f I I I III-II l IJ|'|‘I1 ‘ I ll‘ lu Ill THE MLASUHLHENT OF FKLQH BLEE MUSCLE COLOR CHANGgS BY DISK COLCnleTRY BY Marvin.Mathias Voegeli A THEéIS Submitted to the School of Graduate Studies of Michigan State College of agriculture and Applied science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Animal Husbandry 1952 .. I . ,1 nCKn' 0'57delele The author wishes to express his very sincere appreciation and grateful thanns to Lyman J. Bratzler, Associate Professor of animal Husbandry, for his guidance, constructive criticism, assistance and constant encouragement in the conduct of this study. His high qualities will always be an inspiration to greater achievement. The writer wishes to thanx E. I. du Pont de Nemours and Company for supplying the film used in packaging the meat. To Dorothy, his wife, he is deeply indebted for her encouragement, sacrifices and many hours spent at the typewriter in the course of this advanced work. .l I III- I I'll! I l TABLE OF CONTERTJ IntrOdUCtion ......0.0.0....0.0.0..........OOOOOOOOOOO ReView OfI-Iiteratu‘e 0.0.000.........OOOOOOOOOOOO0.... A. B. Methods Used to Measure Color ............... Methods Used to Express desults of Color hieaSUI‘ement ......OOOOOOOOOOOOOOOOOOOOO0.0... The Color of Fresh Lean Meat ................ Chemistry of Color Change ................... Factors Influencing the Color of Meat ....... (1.) Hemoglobin Content of the Tissue ..... (11.) Effect of Oxygen Pressure ............ (111.) Depth of Oxygen.renetration .......... (1V.) hffect of Time, Temperature, and helative Humidity .................... (V.) Effect of Antioxidants ............... (V1.) Lffect of Storage in.Different atmospheres .......................... (V11.) Effect of Biological agents .......... (V111.) Effect of Packaging Material ......... (1X.) affect of Fat Content ................ Purpose ......0............OCOOOOOOOOOOOO0.0.0.0000... Experimental Procedure ............................... A. B. C. Sampling Procedure ... Method of Color Measurement ................. Accm'acy Of C0101. hiatCh ......OOOOOOOOOOOOOO. Method of Obtaining Color Reading During Storage 00.0.00.........OOIOOOOOOOOOIOOOO.... conditions Of Storage ......OOIOOOOOOOOOOOOOO 10 13 l3 15 17 4O 4O Page F. Conditions of Sample Comparisons ............ 41 (1.) Color Difference Due to Animal ....... 41 (11.) Effect of aging ...................... 42 (111.) Effect of Storage in a Film .......... 42 (Iv.) Effect of Light ...................... 43 (V.) Effect of Freezing ................... 45 (V1.) Effect of Delayed Wrapping ........... 45 Results and Discussion ............................... 47 (1.) Color Difference Due to Animal ....... 55 (11.) Effect of aging ...................... 58 (111.) affect of Storage in a Film .......... 61 (1V.) Effect of Light ...................... 64 (V.) Effect of Freezing ................... 73 (VI.) Effect of Delayed Wrapping ........... 76 Summary .............................................. 86 Bibliography ......................................... 88 Appendix ......OOOOOOOOOOOO......OOOOOOOOOOOOOO0...... 94 ii Diagram Diagram Photograph Photograph Chart Chart Table I4 n: I4 n: is A) :4 Figure 1 Figure la Figures 2 &.2a Figures 3 &.3a Figure 4 Figures 5 & 5a Figures 6 &:6a Figures 7 &'7a Figures 8 & 8a LFigurea 9 & 9a LIST OF ILLUSTRATIONS Three-Dimensional Concept of Color .. Protoheme Structural Formula ........ Front‘View of Matching Booth .1...... Side View of Matching Booth ......... Hue and Chroma Loci at value 3 ...... Hue and Chroma Loci at Value 4 ...... Munsell Renotations and Index of Fading of Unwrapped Sample Stored inDarkneSB 0......OOOOOOOOOOOOOOOOOO Hue and Value Relationships of Unwrapped Sample Stored in.Darkness . Chroma and Value Relationships of Unwrapped Sample Stored in.Darkness . Color Change of Unwrapped Samples Stored in Darkness 0.0000000000000000 Color Changes of wrapped Samples From Two Different.Animals Stored in Darkness 0000006000000000.090.000.900 Color Change of Samples Cut from the Rib Portion after Aging ............. Color Change of Wrapped and‘Unnrapped Samples Stored in.Darkness .......... Color Change of Unwrapped Samples Stored in.Darkness and Two Sources of Light ......OOOOOOOOOOOOO0.0.00.00... Color Change of wrapped Samples Stored under Two Sources of Light .......... Color Change of wrapped Samples Stored under Two Intensities of Fluorescent Light 0.0.000.........OOOOOOOOOCOOOOO Color Change of‘Unwrapped Thawed Frozen Sample Compared with'Unwrapped unfrozen.Sample ..................... iii Page 30 31 35 36 so 51 51 54 57 60 63 67 7O 72 75 Figures l0 & lOa Figures 11 & lla Figures 12 & 12a Figures 13 & 13a Color Change of Samples Wrapped at Different Intervals after Cutting and Stored under 30 Foot Candles of Fluorescent Light ...... Color Change of Samples Wrapped at Different Intervals after Cutting and Stored under 215 Foot Candles of Fluorescent Light . Color Change of Samples Wrapped at Different Intervals after Cutting and Stored in Darkness .... Color Change of Thawed Frozen Samples Wrapped at Different intervals after Cutting and Stored in Darkness ....................... iv 78 80 82 85 INTRODUCTIOX The color of lean beef is an important factor in the grad- ing and salability of beef carcasses and cuts. The range in beef color is recognized in the retail cuts by the consumer, and his preferences are prouected into the standards for grades. The following expressions concerning beef color are frequently used: dark pink, very light cherry red, light cherry red, slight- ly dark cherry red, moderately dark cherry red, darx red, and very dark red. These descriptive terms are difficult to apply because different individuals may have Varied conceptions of the color described. The develOpment of an obgective color measure- ment that could be applied to meats research and also to meat grading would eliminate different conceptions of meat color. The color of fresh neat is SUOJECt to change. Under com- mercial retailing, discoloration is the major factor in deter- mining tne shelf life of prepackaged meats. The Production and Marketing administration of the United States Department of Agriculture (50) states that discoloration of red meats is ac- celerated by high temperature, too much moisture, and too much oxygen. To help prevent discoloration, this report (50) suggests a "blooming period" of 15 to 30 minutes between cutting and wrapping. During this period the desirable bright red color develops and excess free liquid which causes unattractive appear- ance is removed. Consumers are very critical of meat color and discriminate against meat cuts that show discoloration. Kramer (26) found that 10 per cent of the packages presented for sale daily in self- -1- service meat counters were rewrapped packages. The report of the rroddction and garketing administration (50) states that 8 per cent were rewrapped. The maJor cause for removal and rewrapping of packages was discoloration. This one Cause accounted for 20 per cent of the packages reworked. Iethods for promoting and naintaining desirable, appeal- ing color in self-service meat packages would minimize rework- ing and increase Sales, for in self-service, each package is its own salesgan. Iany customers have eagerly accepted prepackaged neat. On April 1, 1948, there were 178 stores Oifering 100 per cent self- service (45). Three years later there were 3,972 stores (2:). Numerous surveys have been made to find consumer and re- tailer reactions to prepackaged meats. These studies by Anon;- mous (2,4,o,7), Kramer (29,26), Ranta (42), Teitelnan (47) and the United States Department of Agriculture (49) have shown that most store operators experienced an immediate increase in sales after converting to self-service meat retailing, not only in heats, but also in other items. Naturally, these operators were in favor of prepaCkaged meats. Favorable comments made by consumers concerning prepacked self-service meat retailing were: 1. They could shop quicker as there was no waiting. 2. The weight and total price were given on the packages and they could purchase to suit the household budget. 3. They could examine the meat more closely and know Just what they were buying. The reasons some consumers did not prefer prepackaged meats were: 1. They wanted the advice of the butcher. 2. They preferred to see the meat cut, tecause they did not know how long prepackaged meat had been paCkaged. 3. They preferred to see both sides of the meat. This new method gave rise inmediately to technical problems. Several tecnnical studies have sought solutions for these. Heisman and Hagen (57) puolished a guide to retailers who were considering converting to prepackage :Eat. The United States Department of Agriculture Production and Larketing administra- tion (49,50), E. I. duPont de Kemours and Company (3), Armour and Company (5) and other agencies have puolished several re- ports on technical problems. Baker (8) and Gilchrist (lo) have presented reports of similar problems. Allied industries, such as the paper companies and self-service refrigerated case manu- facturers have done a considerable amount of reSearch work. The experiment stations of Michigan, hissouri and new Jersey have been engaged in cooperative studies. Results of these studies have been published by Chamberlain and Bratzler (l5), Gowland (l9), and Voegeli (52) of the Michigan Station and Rikert (43) of the New Jersey Station. Few of these studies have emphasized the color changes of fresh meat. Since the color of meat has been shown to be of great importance, the following study applies disk colorimetry in the obuective measurement of beef color. Color changes as aifected by various treatments were investigated using this if: e thOd . REVIEW OF LITEnATUnE In reviewing the literature on the color of meet, it immediately becomes apparent that reports dealing with color changes of meat as such are scarce. Considerable work has been done with solutions of hemoglobin, one of the meat pigments. Kennedy and Whipple (23) made a study to determine if there was any significant difference between blood and muscle hemoglobin. These authors found that muscle hemoglobin was almost indistinguishable from blood hemoglobin. They found evidence that the pigment fraction of muscle and blood hemoglobin was identical but that there were differences in the globin fractions. Spectrophotometrically, the two are quite similar. Many authors have made no attempt to differentiate blood hemoglobin from muscle hemoglobin. It is thought that the reactions of hemoglobin may be applied toward an understanding of meat color changes, since hemo- globin and muscle hemoglobin, usually called myoglobin, are similar in their reactions and the latter compound is the chief pigment of fresh meat. The term hemoglobin will be used to include both blood hemoglobin and.muscle hemoglobin in this review. A. methods Used to heasure Color heference has been made to both subjective and objective methods of color measurement. Eamsbottom (40) used a committee of three judges to rate the color of beef which had been stored. An arbitrary scale from 1 to lo was established, 1 being extranely poor and 10 excellent. Kraft and Wanderstock (24) modified the strictly subjec- tive method by matching meat color with Xunsell color panels (meat scale A). The panels were used as a standard and the grading was on a scale from 1 to l0 in order of increasing darkness. Nickerson (39) has stated that if a standard that actually matches the project can be established, color panels or charts are often useful. Ridgeway charts, haerz and Paul Dictionary of Color, and Munsell charts have all been used for this purpose. Objective color measurements have been made using spectro-_ photometry, colorimetry, and more recently, the Hunter Color Difference Meter. 1. Spectrophotometry - The color may be measured indirectly by specifying the stimulus, completely or partially, in terms oi reflectance or transmittance at each wave length in the visible spectrum. a. Colorimetry - Color may be matched by the use of secondary standards such as filters or disks. -5- 3. Hunter Color Difference Meter - This instrument is a tristimulus colorimeter that measures color on three scales: L scale - visual lightness. a scale - redness when plus, gray when zero, and greenness when minus. b scale - yellowness wnen plus, gray when zero, and blueness when minus. B. methods Used to Express Regults of Color Measurement Nickerson (39) has listed three methods of color notation which are widely used in reporting color measurements. 1. International Commission on Illumination method of color notation - The results of instrument measure- ments are reduced directly into terms of the standard observer and coordinate system of colorimetry. The data are expressed as the absolute (X,Y,Z) and fractional (x,y,z) amounts of three imaginary red, green and blue lights necessary for an imaginary standard observer to match a given sample under a given illuminant. Homogeneous-Heterogeneous Method of Color Notation - In this method of color notation the results of color measurements are reduced through conversion from I.C.I. notation into terms of the homogeneous- heterogenous system in which a mixture is made or calculated for the amount of spectrum light of a -6- homogeneous nature and the amount of heterogeneous light needed to match a given sample. Luminous reflectance or transmittance is measured separately. The wave length of the homogeneous light needed to match the sample is called the dominant wave length of the sample; and the purity is the relative amount of neutral light needed to desaturate the homogeneous spectrum light to match the sample under a chosen illuminant. 3. hunsell.Method of Color flotation - This method may be used directly if measurements are made by comparison to‘Munsell charts, or it may be used indirectly by converting I.C.I. notations into Munsell notations. Color is expressed in units of visual difference of three psychological attributes; hue, lightness, and saturation. Results are expressed in terms of color order rather than color mixture and allow an inter- pretation of results directly in terms of the visual qualities hnown in the Munsell system as hue, value and chroma. Munsell hue is that attribute of certain colors in respect to which they differ characteristically from a gray of the same lightness and which permits them to be classed as reds, yellows, greens, blues, or purples. The Munsell circuit is divided into 10 major hues: R - red BG - blue green YR - yellow red B - blue Y - yellow :8 - purple blue GY - green yellow P - purple G - green RP - red purple Munsell value is that attribute of all colors which permits them to be classed as equivalent to some member of a series of greys that are equally spaced under the standard conditions for which the scale was derived. The Munsell scale of greys extends from 0, black, to 10, white. Munsell chroma is that attribute of all colors possessing hue which determines their degree of difference from a gray of the same value. The notation is numerical, with 0 at gray, extending outward from the neutrals toward 10 or more for the strong colors. It is important in color work to thoroughly understand the three-dimensional concept of color. The following diagram illustrates hue, value and chroma in their relation to one another. The circular band represents the hues in proper sequence; the vertical center axis represents the scale of value; the paths outward from the center represent scales of chroma, increasing in strength in the direction indicated by the numbers. (Drawing by F. G. Cooper, from Munsell Book of Color.) Diagram 1 -8- C. TheColor of Fresh Lean meat Br00ks (13) stated that the color of meat was due to the presence of a complex and relatively unstable compound known as hemoglobin. Brooks (9) reported that hemoglobin was present as muscle hemoglobin, and also in any blood corpuscles remaining in the capillaries. In another paper, Brooks (ll) confirmed that the reddish color (hue) of fresh lean meat was due to the pigment muscle hemoglobin found within the muscle fibers. The depth of color (which corresgonds roughly to the two other attributes of color, brilliance and saturation) depended on the concentration of hemoglobin and on the thick- ness of tissue from which light was reflected to the eye by optical heterogeneities within the muscle. The thicker the surface layer and the greater the concentration of pigment, the deeper was the color. Whipple's work (55,56) showed that the amount of muscle hemOglobin present appeared to be independent of the degree of blood removed and dependent on the type of muscle, as well as the breed, age, and condition of the animal. Levers (29) stated that the color of hemogldbin was dark red or purple and was responsible for the dark color in the interior of meat seen on the exposed surface when it is first out. In fresh lean meat exposed to air, Brooks (ll) said that the purplish reduced hemoglobin was found in the tissue underlying the surface layer. Hoagland (21) stated that the red color of fresh lean meat was due to oxyhemoglobin, which is one of the constituents -9- of the blood remaining in the tissues, and to a similar compound which is a normal constituent of the muscles. Lavers (29) found that oxyhemoglobin was bright red and was reaponsible for the attractive bright red color of meat. According to Brooks (ll) the red oxyhemoglobin was found only in a well defined surface layer. The dark brown color in meat is due to methemoglobin (29). Brooks (13) found that the color of lean meat was brownish when about 60 per cent of the hemoglobin present in the super- ficial layer was in the form of methemoglobin. Drying, or dehydration, also caused a color change. Brooks (ll) offered the following explanation for the cause of this color. The rate of evaporation of water from muscle depended on the rate of movement of water through the muscle up to the evaporating surface and the rate of diffusion of water vapor from this surface into the outer atmosphere. With large muscles there appeared to be a sufficient difference between these to give a sharp concentration gradient of water near the exposed surface of drying. D. thmistry of the Color Chaggg Haurowitz (20) has reported that hemoglobin consists of two components, a prosthetic group called protoheme, and a protein group called globin. He stated that the prosthetic group is the same for all hemoglobins and myoglobins and shows the structural formula for this to be as follows: -10.. HC C //C CH I Cde Q \\N C CCH3 \\" (a N// .N HOOCCHngzc---C&¢ h §§Y CCH===CHZ J / \ q. Cd_____? C on HOOCCHZCHZC CH3 Diagram 2 - Frotoheme This compound is made up of four methyl groups (CH3), two vinyl groups (CH===CH2), two propionic acid radicals H 1' J HC/ \ H" (CHECHZCOOH), and four pyrrole rings I which make up HC CH the porphyrin ring in combination with iron (Fe). There are three main forms of hemoglobin which explain the color changes of meat: hemoglobin (purple), oxyhemo- globin (red), and methemoglobin (brown). The color of the meat is greatly influenced by the relative concentrations of these compounds. Eirie, according to haurowitz (20), has illustrated the structure of hemoglobin and important reactions of the iron atom by the following formula. The porphyrin ring is symbolized by the four nitrogen atoms of the pyrrole rings. -11- N K N “If ‘ ‘— e“.- rd iv iv Globin— 'e/ Globin Fe(-—-O2 Glob in Fe{—OH / / E ii h N K’ h Hemoglobin nyhemoglobin Kethemoglobin The iron is in the ferrous (Fe+*) state in hemoglobin (29). In oxynemoglobin the iron is also in the Ierrous (re*+) state, but the compound contains more oxygen than reduced hemoglobin. The oxygen is held only in loose combination. Only oxygena- tion of hemogIODin and not true oxidation has taken place when oxyhemoglobin is formed, since there is no change in Valence of the iron. In methemoglobin the iron has been oxidized to the ferric (Fe+++) state. Lavers (29) stated that oxyhemoglobin is not an inter- mediate in the formation of aethemoglobin. He gave the path of the discoloration reaction as: oxyhemoglobin-———+reduced hemoglobin-———1methemoglobin. Using only the portion of Jensen's (22) diagram which pertains to fresh meat, the color change is shown diagramatically as: Oxyhemoglobin 02 ‘Hemoglobin HbO (red) 4 ‘THb (purple) Ferro-compound Ferrgfcompound Other oxidation pigments Methemoglobin (Green, gray-brown i LHb (brown) Perri-compounds Perri-compound we. E. gactors Influencing the Color of Meat (I) Hemoglobin Content of the Tissue Shenk, Hall and King (44) made a study to determine the hemoglobins in beef muscle tissue. They found that muscle hemoglobin in animals full fed grain while on pasture averaged about 16 per cent higher than in animals full fed in dry lot. animals on pasture alone averaged 37 per cent higher than the animals full fed in dry lot. These authors felt that the difference was not due to nutrition but was due to the increased exercise that the pasture animals were required to take in obtaining their food. Whipple (55), in a study of striated muscles of the dog, found that the leg and back muscles showed a great range in their muscle hemoglobin content. This variation appeared to depend upon exercise and it determined largely the latent muscular power. Whipple also found that as the animal grew older the muscle hemoglobin content increased. (Adult dogs had considerably more hemoglobin present than young dogs and . the adult dogs varied all the way from 400 mgm. per 100 grams hemoglobin in a quiet house dog to 1000 mgm. per 100 grams hemoglobin in an active, trained hunting dog. Whipple (56) also studied the variations in hemoglobin content in striated dog muscle due to anemia or paralysis. He found that severe anemia may reduce the level of muscle hemoglobin slowly. If the original hemoglobin content was high he found that the reduction due to anemia might even -13- amount to 30 or 40 per cent. Muscular paralysis was followed by a fairly rapid loss of muscle hemoglbbin. after a period of seven weeks some paralyzed muscles contained only one-half as much.muscle hemoglobin as normal muscles. This showed the relationship between muscle hemoglobin and exercise and that exercise was more important than anemia in determining the level of muscle hemoglobin. according to Millikan (32) about one-fourth of the living bOdy's hemoglobin is in the form of muscle hemoglobin. The muscle hemoglobin is generally found in large quantities in those muscles requiring slow, repetitive activity of consider- able force. Examples are the heart muscles of larger mammals, breast muscles of the larger flying birds, and leg muscles of running animals such as the horse and dog. The same muscles nmy'vary'widely in.redness from individual to individual and from time to time, depending upon the amount of use to which they are put. Watson (53) measured the concentrations of hemoglobin in different muscles of the same animal and in animals of differ- ent breeds. He found the muscle hemoglobin made up a high percentage of the total hemoglobin in beef muscle. In sheep and pig muscle the percentage of muscle hemoglobin was considerably less. This would account for the darker color in beef muscle than in sheep or pig muscle. The results of these workers would indicate that the amount of hemoglobin in.meat is dependent on the type of -14- muscle, exercise, age, breed, and condition of the animal. (11.) Effect of Oxygen Pressure Neill (37) has shown that there was no evidence that methemoglobin was formed in the complete absence of oxygen, since in this condition there were no oxidizing agents formed to oxidize hemoglobin to methemoglobin. Brooks (9) also showed that when hemoglobin was stored in pure nitrogen storage there was no formation of methemoglobin. From this work it was apparent that oxygen was necessary for the formation of methemoglobin, the dark colored pigment. The reaction in the formation of methemoglobin was from oxyhemoglobin-———-preduced hemoglobin-—-—-’methemoglobin. Brooks (12) found that at 30°C (86°F) oxyhemoglobin dissociated rapidly to reduced hemoglobin as the oxygen pressure dropped ‘below 80 mm. mercury. Since the formation of methemoglobin was dependent on the formation of hemoglobin from oxyhemoglobin one would expect discoloration to proceed rapidly at an oxygen pressure below 80 mm. mercury. Neill and Hastings (38) have substantiated this. Working with hemoglobin solutions, these workers found that at 30°C (86°F) the rate of methemoglobin formation was greatest when the partial pressure of oxygen was about 20 mm. of mercury. Brooks (9) found this to be true for the oxidation of hemoglobin in muscle. He found that at this oxygen pressure the concentration of hemoglobin nearly equals the oxyhemoglobin concentration. The rate of -1j- methemoglobin formation was monomolecular with respect to the hemoglobin concentration at a constant oxygen pressure. At 0°C (32°F) Brooks (13) found the rate of methemoglobin formation was greatest when the partial pressure of oxygen was 4 mm. of mercury. It would seem that the oxygen pressure required for optimum methemoglobin formation is dependent on the temperature. Brooks (12) found that in muscle tissue the concentration of oxygen decreases with increasing distance from the muscle surface. In air the rate of oxidation in the oxygen region increases with increasing distance from the surface. The smaller the pressure of oxygen in the gas in.which the tissue was stored, the nearer to the surface was the region where methemoglobin was most rapidly formed, since the depth of oxygen region was proportional to the square root of the oxygen.pressure. The relation between oxygen pressure and the rate of methemoglobin formation was responsible for the rapid dis- coloration of tissue stored at 0°C (32°F) in gases containing a small amount of oxygen. Brooks (ll) found that methemoglobin formed directly on or very near to the surface altered the color of reflected light to a greater extent than the same amount of pigment produced in the same time but some distance (2 mm. or more) below the surface. In tissues that were still reddish on the surface, Brooxs (9) found that the difference in rate at different distances from the surface was great -15- enough to form a yellow brown zone (containing mainly methemoglobin) immediately adgoining the region of reduced hemoglobin. (111.) Depth of Oxygen Penetration Since methemoglobin was slowly formed on exposure of hemoglobin to oxygen the formation of methemoglobin in muscle exposed to air was confined to a thin surface layer. Brooks (9) found that the tissue had a small oxygen uptake so that given sufficient time a "steady state" was reached where the depth of oxygen penetration was determined by the rate of diffusion of oxygen into the tissue and the oxygen consump- tion. He showed that the depth of the oxygen penetration was determined by the oxygen pressure in atmospheres at the surface of the tissue, the diffusion coefficient of oxygen through the tissue, and the oxygen uptake of the tissue. Brooks (9) found that any factor which altered the depth of the penetration of oxygen into the tissue also affected the discoloration of the tissue. The discoloration of the tissue was confined to the thin superficial layer where oxygen had penetrated. ' Brooks (ll) found that different fresh ox-muscles in air at 0°C (32°F) from the same animal showed values of depth of oxygen penetration varying from 2 to 5 mm. The depth of oxygen penetration showed a slow increase with time, and a rise in temperature decreased the depth. The depth of oxygen -17- penetration was prOportional to the square root of the oxygen pressure of the atmosphere. (IV.) Effect of Time, Temperature, and nelative Humidity Since it has been shown that oxygen penetration of the tissue is neceSSary for the formation of methemoglobin, factors which affect oxygen penetration affect discoloration. Brooks (13) has shown that the depth to which oxygen penetrated the tissue decreased with increasing temperature. tenetration increased slowly with time but rarely exceeded one centimeter even after very long periods of storage. The onset of discoloration is closely connected with the faCtors governing the loss of water from the meat. At high humidities, 99 per cent relative humidity at 0°C (32°F), Brooks (13) found that exposed muscle was discolored by methemoglobin in 20 to 30 days. At low humidities where there was excessive drying, there was a dark appearance due to the optical changes in the tissue very quickly. At 0°C (32°F) Br00ks (10) found that the rate of oxidation in.ox—muscle was slow but that over long periods of storage it produced a marked brown discoloration of the tissue. After the tissue had stood a few hours, Brooks (9) measured the depth of oxygen.penetration and found it to be approximately 2 mm. After 100 hours the depth had increased linearly to approximately 4 mm. In 6-8 weeks the oxidation in ox-muscle was complete in a surface layer of tissue which in extreme -18- cases was 1 cm. thick. at -10°C (14°F) Brooks (13) found no visible discoloration of lean meat stored for 16 weeks. at -1.4°C (29.5°F) there was no discoloration owing to the formation of methemoglobin until 40 to 45 days from killing. Brooks (9) has shown that freezing and thawing meat appeared to increase the rate of methemoglobin formation compared to control tissue which had not been frozen. Mangel (31) included thawing experiments in her work. She found that samples allowed to thaw from one to five times did not show that methemoglobin formation had been increased with repeated thawing and freezing. Mangel (31) stored samples at temperatures ranging from -12°C (10.4°F) to -24°C (-11.2°F). She found that methemo- globin formation was slower in samples stored at the higher temperature than in samples stored at the lower temperatures. Ramsbottom's (40) work would indicate the opposite. He stored fresh beef at six different temperatures ranging from -20°F to 26°F packaged in Du Pont 300 MSAT #87 cellophane. The product stored at 26°F was discolored in less than 30 days, whereas the product stored at -20°F was still scored good in color and appearance after one year's storage. He concluded that the lower the storage temperature the longer the storage life. Ramsbottom and Koonz (41) determined the relative concen- tration of oxyhemoglobin and methemoglobin in the surface -19- tissues of steaks stored for one year at 10°F and —30°F. The absorption spectra curves on extracts of the surface tissue were plotted from spectrOphotometer readings. The curve found for steaks stored at 10°F for one year was quite similar to the curve for methemoglobin. The curve for steaks stored at -30°F indicated a mixture of oxyhemoglobin and methemoglobin. This indicated that a greater oxidation and consequently darker beef occurred in the superficial lean tissues at 10°F than occurred at -30°F. Rikert (43) found that when unpackaged meat was stored at 34°F, 54°F, and 85°F the rate of initial darkening increased as the storage temperature increased. When.meat was packaged under vacuum, Rikert (43) found an initial decrease in redness followed by a return to redness which had in many cases a higher redness value than the original. The time required for the return of the red color in the packaged meat was also shortened as the storage temperature increased. (V.) Effect of Antioxidants Kraft and Wanderstock (24) dissolved antioxidants in a filtered cocoanut oil carrier and brushed this on the surface of meats. The meats were packaged and stored. They found that antioxidants were most effective for checking undesirable color changes in beef round steaks during the first 24 to 48 hours. Nordihydroguaiaretic acid in 0.01 per cent concentra- tion inhibited color changes in round steaks for 144 hours. -20- All of the antioxidant treated samples retained color better than did the untreated ones. Bikert (43) concluded that the effect of 0.05 per cent nordihydroguaiaretic acid was not consistently toward either improvement or degradation of the meat color. When hemoglobin solutions were shaken in air with the addition of ascorbic acid, Lemberg, Legge, andeockwood (30) noted the formation of green bile pigments. Vestling (51) demonstrated that if controlled conditions were used, ascorbic acid could be used in reducing methemoglobin to hemoglobin at 0°C (32°F). Chang and watts (16) found that at 45°C (113°F) the addition of .1 per cent ascorbic acid to hemoglobin caused oxidation of the red color followed by conversion of the hemoglobin to a green hemochromogen. Watts and Lehman (54) concluded that ascorbic acid protected hemoglobin solutions when it was added in low concentrations at low temperatures. At high concentrations and high temperatures it brought about discoloration. Lavers (29) treated wrapping material with ascorbic acid and sodium bisulfite. He found that ascorbic acid was of littka value in preventing discoloration while sodium bisulfite was quite effective. (VI.) Effect of Storage in Different atmospheres Brooks (11) investigated the effect of carbon dioxide at 0°C under conditions where there was little or no drying of the tissue. He stated that there were two possible effects '21- of carbon dioxide. 1. .A change in the depth of oxygen penetration.into the tissue in addition to the decrease caused by the diminution of oxygen.pressure in the gas mixtures. 2. .A change in the rate of methemoglobin formation. Brooks (11) found that in concentrations of carbon.dioxide below 20 per cent the rate of oxidation.of hemoglobin in muscle was not affected to a significant extent. If other conditions of storage were the same, the color changes of lean meat in air and in air containing 20 per cent carbon dioxide were the same. Mangel (31) stored samples under atmospheres of nitrogen, oxygen, and carbon dioxide with air as the control. She found no significant difference but the methemoglobin.formation tended to be slower when the tissue was stored under oxygen than under the other gases. Rikert (43) flushed packaged samples with carbon.dioxide and nitrogen.before evacuating. This resulted in less initial darkening than that which occurred in samples evacuated without flushing. He also stored samples at atmospheric pressure in carbon dioxide and nitrogen, This had a detrimental effect on the top surface color but improved the bottom surface color when compared with samples stored in air. (VII.) Effect of Biological.Agents Neill (34) made an investigation of the oxidationp reduction.activities of Pneumococcus based upon the -22- physical-chemical relations between oxyhemoglobin, hemoglobin and methemOglobin. SuSpension of living cells and relatively large amounts 'of sterile Pneumococcus extract respectively were added to sterile solutions of methemoglobin which were then sealed from the air. Analysis proved the complete absence of both oxyhemoglobin and molecular oxygen. In the absence of air, Neill found that living Pneumococci and sterile cell extracts prepared from them reduced methemoglobin to hemoglobin. When oxygen was present, the extract formed oxidizing agents which oxidized hemoglobin to methemoglobin. Neill (35) made a similar study using anaerobic bacilli. He found that anaerobic bacilli have the ability to oxidize hemoglobin or reduce methemoglobin. The Optimum conditions were provided when the oxygen tension was sufficient for the formation of an active concentration of oxidizing agents without preventing the necessary oxygen dissociation of the oxyhemoglobin. In the absence of oxygen, anaerobes did not oxidize hemoglobin to methemoglobin. autoxidizable substances formed during the autoxidation of pure oleic and linoleic acids and of substances present in turpentine, cod liver oil and linseed oil have been shown by Neill (36) to oxidize hemoglobin to methemoglobin. nutoxidiz- able substances were extracted by alcohol from meat infusion and from potato Juice. Mixtures of the alcohol soluble substances from Either the animal or plant Juices consumed -23- IB-RUw-HL‘ili - K‘ molecular oxygen.with the formation of oxidizing agents capable of oxidizing hemoglobin to methemoglobin. Hemoglobin is oxidized to methemoglobin if oxygen is present while the reverse reaction is induced if oxygen is excluded. The presence or absence of molecular oxygen determines the direction of the reaction.induced by these autoxidizable substances. Neills' studies have shown that “spontaneous“ formation offimethemoglobin.which occurs in sterile drawn‘blood or in ~ sterile hemoglobin.solutions can be prevented by maintaining the hemoglobin system.rendered oxygen-free by biological reducing agents. Since methemoglobin is known to be the oxidation product of hemoglobin it would seem certain.that its ”spontaneous" formation is an oxidation. Neill (37) has shown that the presence of oxygen is necessary for the "spontaneous“ formation of methemoglobin in blood or in.hemoglobin solutions either at ordinary temperatures or at 55°C. (VIII.) Effect of Packaging Material Lovers (29) tested several packaging materials and found that discoloration was not a function.of any particular packaging material. The cause of discoloration was the change of the oxyhemoglobin.to hemoglobin.and this to methemoglobin. Levers (29) stated that when.an.oxygenpimpermeable film was placed on.meat, conditions suitable to rapid discoloration -24- were present. This was due to the supply of oxygen from the air being cut off and a lowered oxygen pressure beneath the film due to diffusion and bacterial action. Allen (1) relates that Du Pont laboratory research has shown that in addition to oxygen permeability, low water-vapor permeability and a certain degree of water-absorptive power are important in maintaining desirable color. a suitable film must have a proper balance of these properties. Du Pont 300 MSAT #80 cellophane has been shown to be effective in holding the color of fresh meat for periods of 72 hours and longer when stored at 34°F to 40°F. This film is characterized by having a "wettable" surface which must be kept in contact with the meat. The oxygen permeability is relatively low as is its water-vapor permeability. The low water-vapor permeability is important in.maintaining color because excessive drying of the meat surface contributes to change in color. The relative humidity of self-service cases may average as low as 60 per cent, therefore, films with high water-vapor permeability may cause excessive loss in weight of the packaged meat. Temperature affects bacterial and enzymatic action which may also play important parts in the retention of color. Allen (1) relates results from an independent laboratory in which 300 MSAT #80 cellophane was one of the films used. 0n the average, the meat wrapped in 300 MSAT #80 cello- phane remained bright and salable for seven to nine days. -25- Steaks in other films were generally discolored at the end of two or three days. There was no bacteriostatic action as the counts were high on all steaks. Kraft and Wanderstock (24) used four different films in their study with antioxidants. They found that a rubber base film gave the best color retention in beef round steaks. Round steaks packaged in films which gave greater retention of color also responded to a greater extent to antioxidant treatment than did the samples packaged in films allowing greater color change. Rikert (43) found that his control samples underwent, in general, the same color change when packaged in cans, poly- ethylene film and cellophane-pliofilm laminate film. (IX.) Effect of Fat Content Mangel (31) added from zero per cent fat up to 25 per cent fat to ground lean beef. For comparison with the ground beef to which no fat was added, one pound unground pieces of the same beef were used. Mangel (31) found that samples containing more than 15 per cent fat showed higher methemo- globin content than those containing less than 15 per cent fat. She observed no difference in the all lean ground samples and the unground samples. This would indicate that the amount of fat in a muscle may influence discoloration. PURPOSE The main purpose of this investigation was to study the application of disk colorimetry as an obJective measurement of fresh beef color. Using this method, it was the purpose to gain information on the color changes as affected by: I. II. III. IV. V. VI. Color Difference due to Animal Aging Storage in a Film Light Freezing Delayed Wrapping BandIMnNTAL PnOCEDURE A. fiampling Procedure Beef was the only meat used in this study. It was secured from animals killed in the Michigan State College meats laboratory. The animals were killed in the usual manner and placed in the laboratory cooler at approximately 34°F for chilling. Seven different animals were used to secure samples: No. of Animal Description Grade Samples I 2 year old Hereford steer Average prime 1 II 2 year old Angus steer average prime 6 III 2Ayear old Hereford steer average choice 4 IV 18 month old Angus steer High choice 4 V 2 year old Hereford steer High commercial 8 VI 20 month old Hereford heifer Low choice 2 VII 18 month old Hereford steer Low choice 18 The longissimus dorsi muscle was used exclusively throughout this study. After the carcasses had been chilled at least 48 hours the wholesale rib portion was removed. at the beginning of each sample run, the rib cut was taken from the cooler to the meat laboratory cutting room. The cutting room temperature ranged from 55 to 70°F, being mostly about 64°F. The longissimus dorsi muscle was removed and cut into steaks three-quarters of an inch in thickness to be measured for color. B. Method of Color Measurement The instrument used to measure the color is shown on pages 30 and 31. The matching booth was made from plywood -48- and painted with blackboard paint to minimize light reflectance. The other equipment used for disk colorimetry in the matching booth were as follows: 1. Electric motor and controls with Hunsell disks. 2. sample standard. 3. Baush and Lomb Optical eyepiece. 4. Mac Beth 300 watt daylight lamp. 5. Black curtains. The Mac Beth 300 watt daylight lamp produces a color temperature of approximately 68000 Kelvin. This is Just a few degrees different from Illuminant C, the light Specifi- cation set up by the International Commission on Illumination under which colors should be matched. This lamp was mounted on the sIOping back of the matching booth so that the angle of the light on the meat surface was 30 degrees. The Munsell disks were backed by a calibrated heavy cardboard disk so that the percentage of each disk used could be.read directly. Red, yellow, white, and black disks were used as suggested by Nickerson (38) and had the following Hunsell notation: Renotation troduction ho. Yellow - 5y8/12 5.5x 8.13/1z.o 3036 White - N9 N8.bO/(Y 0.3) 3551 Black - NI Nl.ll/(PB 0.2) 3556 The prepared sample was mounted upon a fitted plywood 58m 323% .3 so; pcoaa .. > m e“. 3‘ l- backing piece before placing it on the sample stand. This made it possible to remove and replace the sample and still have the same Sample area viewed in matching the color. This was found important as different areas of a muscle gave different results depending upon the concentration of intramuscular fat. By adgusting the Sample so that the top .surface was at the same level as the diSks, equal viewing areas of the sample and disk mixture were obtained. This area was 2 cm. square at 8 3/4 inches from the optical eyepiece base. Since color is three dimensional, to match a sample, these three points were considered: 1. Are the spinning disks redder or yellower than the sample? 2. are they brighter or darker than the sample? 3. Are they stronger or weaker than the sample? Practice and experience were important in obtaining the desired result when adgustment of disk mixtures was made. The experienced observer knows what the addition or subtraction of the individual colors will do to the resulting color mixture. Adjustment of the disks was continued until a satisfactory match with the sample was obtained. A match was not an exact matter in all cases. It was made within a tolerance, with the reduction of that tolerance to the smallest size possible. Cases were found where the addition of one unit of yellow, for example, would change -32- the disk.mixture from slightly lacking in yellow to too much yellow. used in the reading. In such cases the lesser units of yellow were always Since this Study was one of comparison of the same samples over a period of time, as long as this was followed results seemed valid. Upon reaching a satisfactory match of the sample the areas of the diSk mixture were recorded. By knowing the International Commission on Illumination (I.C.I.) tristimulus values (X,Y,Z) of the individual disks and knowing the number of units used in the match, it was possible to calculate the Hunsell renotation. Eroduction No. X_ Y Z Red disk - 534/14 3605 .2283 .1305 .0 54 Yellow disk - 5y8/12 3636 .5794 .6143 .0 65 white disk - N9 3551 .7204 .7435 .8409 Black disk - NI 3556 .0133 .0136 .0173 Suppose that the sample required 32 per cent of the red, 5 per cent of the yellow, 2 per cent of the white, and 01 per cent of the black to match the meat sample. The tristimulus values (X,Y,Z) for this colOr were obtained as weighted means of the (X,Y,Z) data for each disk used, the weights being proportional to the disk area. A Y Z 32%(X,Y,Z) red disk .0731 .0418 .0177 5%(X,Y,Z) yellow disk .0290 .0307 .0043 ,2s(x,y,z) white disk .0145 .0149 .0168 ol£(X,Y,Z) black disk .0081 .0083 .0106 Tristimulus values of sample color.l247 .0957 .0494 Fractional values (x,y,z) -33... x=.462 y:.355 Z: 0 183 I. To convert these data to the Munsell notation it was necessary to refer to a table of I.C.I. (Y) equiva- lents of the recommended hunsell value scale (V) from O/ to 10/. From this table, for Y = .0957 it was found that hunsell value (V) was 3.60. Since V = 3.60/, Munsell hue and chroma were found by interpolation between the Charts for value 3/ and 4/ (See pages 35 and 36) to locate the hue and chroma loci at this value. at value 3/ for x = 0.462 and y = 0.355, the munsell hue was 1.5Yh and the chroma was /5.0. at value 4/ for x = 0.462 and y,- 0.355, the hue was 0.6YR and the chroma was /6.2. Since 3.60 is 0.6 of the distance between 3/ and 4/, the interpolated hue will be that of value 3/ minus 0.6 of the difference between the hue read from values 3/ and 4/. Since the hue on the 3/ chart was 1.5YR and on 4/chart was 0.6YR the interpolated hue was found to be 1.5 - (0.6(1.5-0.6)) = 1.0YH. The interpolated chroma will be that at value 3/ plus 0.6 of the difference between the chromas read from values 3/ and 4/. Since the chroma on the 3/ chart was 5.0 and on 4/ chart was 6.2 the interpolated chroma was found to be 5.0 - (0.6(5.0-6.2)) - 5.7. The complete notation for the meat sample was found to be 1.0YR 3.60/5.7. -34- ‘ 7 '0 , .IE .20 ~ - ’_ . ”'94'3') = (5.555 percent refleclonce —- 006555 Y for lCI Illumunont L. . ' '- . the é’h'mht each radiaiing hue line. From "Final Report of the 0.S.A. Subcommittee on the spacing of the Munsell Colors," (J. Opt. Soc. Am. 32, 385—418, 1943). Indig-g'ed irJ “st'e'vs‘sfi 2.}he inr‘er ovoid being /2 . V. ,. Hue is ‘fiai‘bied near .50 .15 CQI’Omu is .l5 .25 ‘ . .55 .60 .15 .15 .20 .25 . .35 ‘ ' . ' .45 .55 .60 X It r 4 I943): 12.00 percent reflectance =O.|200'Y for |C| Iliuminont C. . . near the end Of each radiating hue line. - Fvom "Final Report of the 0.8.A. Subcommittee on the Spacing of the Munsell colors," (J. Opt. Soc. Am. 32, 385-418, 191.3). '5 i"diCDted in steps of 2, The inner ovoid being /2. The procedure followed by making a single color reading and then obtaining the Munsell renotation of that reading has been presented. In this study a series of readings from the same sample area were made to measure the color changes that occurred during the storage of that sample. To discover the relation between successive readings, they were plotted. since color is three-dimensional, no two-dimensional diagram will reveal all relations. Hickerson (38) suggests that by plotting hue (horizontally) against value (vertically) on one graph and then chroma (horizontally) against value (vertically) on another graph the significance of the color relations should become apparent. To express color differences in terms of a single number instead of in three numbers (hue, value and chroma) color difference formulae have been devised. Sample readings are compared to a standard. Nickerson (38) based a small color difference formula on.hunsell scales of hue, value and chroma. Judd, Scofield and Adams (38) have also presented formulae for this purpose. The Nickerson formula is easy and quick to apply. It is as follows: I (index of fading) = Q (2AH)+ 6AV+3AC b C - chroma of sample DH.— difference in hue between sample and standard AV'- difference in value between sample and standard AC a difference in chroma between sample and standard To show the relationship between successive readings -37.. this formula was used. The standard used for readings of meat taken through cellophane was IYR 4.0/6.0. The standard used for readings of the meat surface direct was 10R 4.0/7.0. The difference in the standards was due to the effect of the cellophane. Since the sample used in computing the example Munsell renotation was wrapped in cellophane its standard was 113 4.0/6.0. Standard notation - l.0YR 4.0/6.0 Sample notation 1.0YR 3.60/5.7 C = 507 AV = 004 AH . 0 no a 0.3 I . 95; (20H) +6AV+3AC I . 532 (2 x o)+(6 x 0.4)+(3 x 0.3) I = 303 By use of this formula, it has been shown that the sample reading was 3.3 units from the standard. By following this procedure, it was possible to find the position of subsequent sample readings in relation to the standard. These positions were plotted against time to snow the color changes of the sample by a single number instead of hue, value, and chroma quantities. -38- C. Accuracy of Color Match It has been estimated that at least one male out of every ten is affected by color blindness to some degree (38). It is therefore important that one working with color should have some check on his accuracy in matching colors. The following procedure was used to check the author's accuracy. Instead of the metal standard to hold the muscle sample, a second motor with spinning disks was mounted. The disks used on the two adJacent motors were the same. The disks on the second motor were set by an operator at percentages unknown to the author. The motor with this disk mixture was set to spinning. The author then came to the matching booth and attempted to match this mixture by altering the disk percentages of the first motor. Definite settings of the unknown disks were made in the following ranges: Red - 14 to 28 units Yellow - 5 to 14 units White - 2 to 8 units Black - 50 to 72 units 6- The author was able to match the unknown disk mixture exactly in all cases but one. In the case where the match was not exact, the error was only 1 unit of the red disk which resulted in an error of only 0.3 hue steps and 0.3 chroma steps, a rather insignificant variance. It is the author' belief that color matches of the meat samples were reasonably accurate. -39.. D. Method of Obtainigg Color Reading Duripg Storagg After the steak sample was prepared and placed in storage, following a procedure to be described later, color matches were made with the spinning disks. The matching booth was installed in the refrigerated storage room. Several color measurements from the same area of the sample were made during the first few hours immediately after placing the sample in storage. Throughout the remainder of storage the color reading was obtained at approximately 24 hour intervals. In.many cases, sample storage was continued beyond the time when the sample was considered unsalable. On several occasions 2.or 3 judges viewed the sample to determine ‘whether it was still salable from the standpoint of color. However, it was impossible to have this done throughout the study, and the time of unsalability as reported was the estimate of the author. Samples which were stored wrapped in a transparent film were matched through the film. E. Conditions of Storggg Three general conditions of storage were held as constant as possible throughout the study. Temperature, relative humidity, and air.movement varied only to the degree prevailing in.the meats laboratory cooler. The wholesale rib cut from which the individual steaks to be matched were cut, and the steaks studied were held under these same conditions. -40- The temperature was recorded by means of a Honeywell Recording Potentiometer. This machine automatically records the temperature by use of thermocouples, and these were distributed in the cooler. Readings from this instrument showed that the temperature varied from.309F to 369F throughout the period of this study. The relative humidity was recorded by use of a Foxboro Dynalog Dewpoint Temperature Recorder. This instrument records dry bulb and dew point temperatures, from which the relative humidity can be determined. The relative humidity varied considerably, depending upon.how much the cooler was being used. It varied from 65 to 90 per cent throughout the study. The most common.relative humidity range was 75 to 85 per cent. Air movement was determined by use of a Hastings Air Meter. This instrument.records air movement in feet per minute. Readings showed that the air movement across the samples was 15 to 20 feet per minute. F. Conditions of Sample Comparisong, (1) Color Difference due to Animal Samples of the longissimus dorsi muscle of different animals were treated similarly to determine if there were color differences in the same muscle of different animals. -41- (II) Effect of aging It was necessary in this study to limit the number of samples placed in storage at one time. Since the time in storage of some samples was for a period of two weeks, considerable time elapsed after removing the first sample from the wholesale rib out until removing the last sample. Comparisons of color changes in samples cut at different intervals of time and then held under similar conditions of storage showed the effect of aging on the color change. (III) Effect of storage in a Film The primary difference between the retailing of meat prepackaged and butcher style is the storing of the retail cut in a transparent film. Prepackaged meat is wrapped soon after the retail cut is made and stored in this condition. In the butcher style of retailing meat, the retail cut is made and placed on trays unwrapped until sold, or cuts are made as demanded. To determine the effect on color of storage in a film compared to storage unwrapped the following procedure was followed: Three-quarter inch steak samples were out. Some were placed unwrapped in storage immediately after cutting. Others were wrapped with cellophane (300 MSnT #80 Du Pont) before placing in storage. -42- w 1 Ntii To wrap a sample the steak was first placed on a Rodeo (brand) Backing Board, so cut that the edges did not extend beyond the steak. The wettable surface of the cellophane was placed against the meat and a tight wrap was made. The film was sealed on the Rodeo Backing Board side by means of transparent adhesive tape. (IV) Effect of Light A survey of markets in the locality offering prepackaged meat showed a variation in light intensity upon the product. The market Operators felt that light was a factor in the discoloration of fresh meat as well as cured meat. It is well established that light causes a fading of cured meats. No report has been noted by this author in which light has been shown to affect the color of fresh meat significantly. The intensity of light on the meat products was measured by means of a Weston Foot Candle Meter which measured the light in foot candles. The variations found were: Market 1 - averaged 60 foot candles Market 2 - averaged 30 foot candles Market 3 - averaged 15 foot candles All of these markets were using white fluorescent light over the fresh meat products. Markets 1 and 2 had lights mounted in the meat cases, and also fluorescent lights mounted from the ceiling above the cases. Market 3 had only fluorescent lights mounted from the ceiling. To duplicate commercial conditions, a battery of fluorescent lights was installed in the sample storage room. By altering the distance of the lights above the samples, different intensities of light were obtained upon the samples. Samples were stored under the following light intensities: l. Darkness - The sample was exposed only to the light required when matching the sample. 4. Thirty foot candles - Storage was under thirty foot Candles of white fluorescent light. 3. Sixty foot candles - Storage was under sixty foot candles of white fluorescent light. 4. Two hundred and fifteen foot candles - Storage was under two hundred and fifteen foot candles obtained by fluorescent light as well as two hundred and fifteen foot candles obtained by incandescent light. A thermometer was placed under the lights to determine if the lights were causing a rise in storage temperature of the samples. Any temperature rise at the sample surface caused by the addition of the lights was noted. (V) Effect of Freezing A portion of the rib cut of animal VII was frozen and stored at O°F for 3 weeks. After thawing at 34°F for 2 days, steaks were obtained to observe the color change of the thawed frozen samples over a period of s torage . (VI) Effect of Delayed Wrapping The United States Department of Agriculture Production and Marketing Administration (50) has suggested that ‘ prepackaged meat should have a "blooming period“ of 15 to 30 minutes before wrapping to help prevent discolor- ation of the product. It is the opinion of the author that immediate wrapping is more efficient if a desirable color can be obtained and maintained for a suitable length of time. The author's personal observations of markets in operation have shown that efficiency of operation is lost when there is a time delay between cutting and wrapping. To determine whether the “blooming period" was advantageous in preventing discoloration, color measurements , ' .45- were made of samples wrapped immediately after cutting and of samples which were allowed a "blooming period" and then wrapped. -45- hESULTS AND DISCUSdICN Two graphic methods of color data presentation have been described in the experimental procedure. To compare these methods, data from a sample stored unwrapped in darkness are presented. These data are shown in tabular form on page 50. Figure 1 illustrates the relationship between hue and value. The sample color renotation 5 minutes after cutting was approximately at the midpoint (5.1YR) of the yellow red hue range at a value of 4.2. After 24 hours of storage the sample color was 5.3 hue steps redder, being in the red hue range (9.8R) and 0.4 value steps darker. With continued storage a maximum redness hue was reached after 111 hours of storage. This was 7.9 hue steps redder than the initial color of the sample. The change in hue was greatest during the first 24 hours of storage as it was 5.3 hue steps redder than the initial color after 24 hours and only 7.9 hue steps redder after 111 hours of storage. After 111 hours of storage the sample color returned toward the yellow red hue range. at 183 hours of storage it was 2.6 hue steps yellower than the color at 111 hours. This was the same hue as the 24 hour color. However, the color was 1.5 value steps darker than the 24 hour color. From the initial reading after cutting until the end of storage the color darkened 1.9 value steps. Figure la illustrates the relationship between chroma -47- and value. The initial color of the sample was weak as indicated by a chroma of only 3.5. The color became stronger during the first 29 hours of storage as the chroma increased 4.0 chroma steps to a chroma of 7.5. The increase in the strength of the color was greatest during the first 150 minutes of storage. After 31 hours of storage the chroma weakened. At the end of storage the color was 0.4 chroma steps weaker and 1.9 value steps darker than it was at the beginning of storage. In the review of literature it was established that the color of fresh meat was greatly influenced by the relative concentrations of the three main forms of hemoglobin; oxyhemoglobin, reduced hemoglobin, and methemoglobin (20,23,39). Oxyhemoglobin was described as being red in color, reduced hemoglobin.purple and methemoglobin brown. (ll,l3,21,29). The color change of the sample illustrated in figures 1 and 1a indicated that: 1. During the first 24 hours of storage there was an increase in the concentration of oxyhemoglobin indicated. This is evidenced by a color change of 5.3 hue steps redder and 3.5 chroma steps stronger. The most rapid increase occurred during the first 150 minutes of storage. 2. From 24 hours until 111 hours of storage there was an apparent increase of reduced hemoglobin. This is evidenced by a change of only 2.6 hue steps redder, -48- 1.0 value steps darker and 1.2 chroma steps weaker. After 111 hours of storage, methemoglobin was the main form of hemoglobin indicated. Brooks (13) found that the color of lean meat was brownish when about 60 per cent of the hemoglobin present in the superficial layer was in the form of methemoglobin. The indicated increase of methemoglobin is evidenced by a change in hue of 2.6 hue steps yellower. Unwrapped Sample Stored in Darkness Trial G - Low Choice 10 Month 01d Hereford Steer Sample cut from rib 3 weeks after slaughter Cutting temperature - 64°F, Cooler temperature - 35°F Standard 10R 4.0/7.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 5 Minutes 5.1TR 4.2 3.5 18.8 10 " 4.3YR 4.1 3.9 16.6 20 " 3.4ra 4.1 4.6 14.1 30 " 2.oYR 4.1 4.9 12.0 40 " 2.1XR 4.2 5.2 11.0 50 " 2.4ra 4.1 5.4 10.6 60 “ 2.1YR 4.1 5.6 9.5 70 " 1.8YR 4.0 5.4 8.7 90 " 1.6YR 3.9 5.8 7.9 110 " 1.6YR 4.1 6.2 7.0 150 " 1.7ra 4.0 6.4 3.6 235 Hours 9.83 3.8 7.0 1.8 285 " 9.6R 3.7 7.5 4.5 303 " 9.2a 3.6 7.5 6.3 55 " 8.5a 3.4 7.1 8.2 79 " 9.3a 3.2 6.2 8.9 87 " 7.9a 3.1 6.3 12.8* 111 " 7.2a 2.8 5.8 16.3 135 " 7.9a 2.6 4.8 19.0 159 " 8.4a 2.5 4.1 20.3 183 " 9.83 2.3 3.1 22.2 *‘Unsalable In..." VALUE VALUE FIGURE I HUE AND VALUE RELATIONSHIPS or: 50.1 hrsWRADPED SAMPLE STORED IN DARKNESS 5mm w” mm «11,. ng‘wd “N O, UNSALABLE DUE To come \10 11,0 ’50 601° (“\"0 fl 4.0" ‘ ”a5 _ ‘40 3.0 m 2.0— (.0 l l I I I I I l I 1 1 MR 5m 4m ave 1m IYR new: 9YR 8R 7R an. ER HUE 5.0-1 ,4 m‘!‘ ‘7! "1 (NH ‘0‘ I“ (d .I‘ 5 mm 401450 ‘p‘o To .0! “ON ‘ 2 H0" 5 4.0“ 00R uoufls 3.0— FIGURE 1a CHROMA AND VALUE RELATION' SHIPS oF UNWRAPPED SAMPLE 1.0“ STORED IN DARKNESS 0 UNSALABLE Due To COLOR 1.0 2.0 3.0 4.0 5.0 5.0 7.0 8.0 9.0 (0.0 “.0 Figures 2 and 2a illustrate the color differences of the same sample in terms of a single number. To use this method it was necessary to select a standard to compare with the color reading. The author made visual observation of several samples in an attempt to select the most desirable color of meat to be used as the standard. These samples were then matched in the matching booth and their color renotated. It was found that the most desirable color renotation of unwrapped meat was near 108 4.0/7.0. This color renotation was used as the standard for unwrapped meat. The standard for wrapped meat was determined by the same means. This was 1TB 4.0/6.0. It should be pointed out that the observed color of lean beef would be somewhat different from the color of color chips or panels having the above notations. When lean beef is viewed by eye the color of the lean and fat are distinct. The color of the lean and fat are blended into a single color when the sample is viewed through the optical eyepiece. Conditions of illumination also affect the sample color. Viewing the sample under the daylight lamp in the matching booth resulted in a different color than when viewed under ordinary conditions of illumination. Comparison of successive sample color measurements with the standard show the color changes during the storage period. The initial color measurement after cutting was 18.9 units -52- from the standard. The sample color rapidly brightened during the first 150 minutes, being only 3.6 units from the standard at this time. After 24 hours of storage the sample color measurement most nearly equalled the color standard. Subsequent sample color readings showed darkening. This increased throughout storage until 183 hours of storage when the sample color measurement was 22.2 units from the standard. This.method shows the combined effect of hue, value, and chroma in brightening and darkening in relation to a color standard. In this method it is impossible to see the relationp ship of the individual attributes. It is possible for two very different colors to be of equal distance from the standard. To emphasize this, after 87 hours of storage the sample color measurement was 12.8 units from the standard. The sample color measurement was 12.0 units from the standard after only 30 minutes of storage. However, the Munsell renotation of this sample at these periods of storage was considerably different. The sample color renotation after 30 minutes was 2.63m 4.1/4.9. This had changed to 7.93 3.1/6.3 after 87 hours of storage, a change of 4.7 hue steps redder, 1.0 value steps darker, and 1.4 chroma steps stronger. To simplify the presentation of the data obtained in this study, the latter method was used. For a more complete analysis of the individual attributes of the color change, the reader is referred to the appendix. -53- 1.0 / 7.0 FROM STANDARD l0 R UNITS 13 FIGURE 2 ~COLOR CHANGE OF UNWRAPPED SAMPLES STORED lN DARKNESS FROM 5 TO 150 MINUTES I I l l l l l l O 2,0 40 60 12.0 I40 80 I00 I50 [0 R 4.0/7.0 U N ITS FROM STANDARD gd 10" FIGURE 24!. - COLOR CHANGE OF UNWRAPDED SAMPLES STORED IN DARKNESS FROM 24 TO 18?) HOURS 4 O UNSALABLE DUE TO COLOR I I l I fi 96 12.0 I44 I68 I92. (1.) Color Difference Due to animal Reference was made to studies (32,44,53,5p,56) that indicated that the amount of hemoglobin in meat was depen- dent on the type of muscle, exercise, age, breed, and condition of the animal. We would therefore expect color differences in meat of different animals. Figures 3 and 3a illustrate the color changes of samples obtained from different animals. The animals compared represent the extreme in the grades used in this study. One animal was a 2 year old.Angus steer graded average prime, the other was a 2 year old Hereford steer graded high commercial. This comparison is not meant to characterize the color of meat in these grades, but is offered to show that there are differences in color. The rate of the color change of these samples was similar for the first 125 minutes of storage. The prime sample darkened rapidly after 24 hours of storage while the commercial sample fluctuated during the interval 30 to 244 hours. After 244 hours the commercial sample darkened rapidly. The prime sample was considered salable until 168 hours compared with 316 hours for the commercial sample. These results are contrary to common belief. The higher grades of beef are generally considered to maintain a more desirable color for a longer time than the lower grades of beef. Within the grades of meat there are color differences so that this one comparison does not characterize the color change of these grades. -55- Tabular data are shown in Appendix h for these samples. The initial color reading of the prime sample shows it to be 1.4 hue steps yellower, .56 value steps brighter, and .6 chroma steps weaker than the initial color of the commer- cial sample. Since different animals show color differences, the following comparisons are made with samples from the same muscle (longissimus dorsi) and from the same animal. UNITS I=ROM STANDARD IYR 4.0/6.0 ‘6 I 3 l 2‘ 4d 6‘ C? Q \ 0. d. d 8 I: > Q g..- o E I— II) ill. 0 o.’ u I; ,4. FIGURE 3 COLOR CHANGES OF WRAPPED SAMPLES 2 FROM TWO DIFFERENT ANIMALS 3 STORED IN DARKNESS FROM 6 To I50 MINUTES ----- TRIAL 2_I, AVERAGE PRIME ANGUS STEEFL -——- TRIAL 8, HIGH COMMERCIAL HEREFORD STEER I I I I l 1 2.0 40 so 80 I00 ILO 0‘ I 00 I p 1 FIGURE 3h - COLOR CHANCE OF WRAPPED SAMPLES STORED IN DARKNESS FRONI 2.4- To 3634' HOURS ---- TRIAL 2| , AVERAGE PRIME ANGUS STEER — TRIAL 8, HIGH COM- MERCIAL HEREFORD STEER. 0 UNSALABLE DUE TO COLOR b I I I I I I I I I I I I I ‘ I I I I I I I I I I I I I G) I I I I I l I .14» 4—8 72. 96 I20 I44- I68 I I I l I 2.441 264 2&5 I I I I I I91 2I6 BIZ. 336 360 .384 408 II. Effect of aging Since it Was impossible to place all of the necessary samples in storage at one time, the effect of aging the rib cut on the color of samples cut at different times was tested. Figure 4 illustrates the color changes of unwrapped samples during the first 6 hours of storage. samples were taken 1 week, 2 weeks, and 4 weeks after slaughter. Tabular data are shown in Appendix B. Differences in the initial color of the samples would indicate that the longer the aging the darker the color. However, this difference in color could be accounted for in the amount of intramuscular fat in the area ol the sample viewed. Since the optical eyepiece blended the lean and fat color, variations were found within a single sample depending upon the amount of intramuscular fat within the area being viewed. The rate of the color change of these three samples was quite similar. The samples out after aging increased in brightness slightly faster but this difference was not great. Neill (37), Brooks (9), and others have shown that methemoglobin is not formed in the absence of oxygen. Brooks (9) measured the depth of oxygen penetration in ox muscle and found that at 0°C (32°F) oxidation (methemoglobin formation) was complete in the surface layer which in extreme cases was only 1 cm. thick in 6 to 8 weeks. Therefore, aging Would affect only the color of tne exposed surfaces of the rib cut. The exposed surfaces were not used in obtaining samples to be measured for color. From this information it would seem that aging does not affect the color of the sample providing the exposed surfaces are removed. Therefore, the effect of aging is not considered in the comparison of treatments which follow. 80R 4.0/7.0 UNITS FROM STANDARD 16‘ FIGURE 4 COLOR CHANGE OF SAMPLES cur FROM THE RIB PORTION AFTER AGING, STORED UNIIIRAepm IN DARKNESS FROM 3T0 394 MINUTES —-—TRIAI. B, [WEEK AFTER SLAUGHTER -———-——TRIAI. F', 2WEEK5 AFTER SLAUGHTER ----- TRIAL O, 3 WEEKS AFTER SLAUGHTER I I00 2.20 .140 .250 p 259 300 310 3, 4o (III.) Effect of Storage in a Film Figures 5 and 5a are graphic presentations to compare the effect of storage in a film with storage unwrapped on the color of the meat. Figure 5 shows the color change during the first 150 minutes of storage while figure 5a shows the color change over a period of hours. The film used for all packaged meat was Du Pont cellophane, identified as 300 MSAT #80. This is a film developed especially for prepackaged fresh meats. The rate of color change of the wrapped and unwrapped samples was approximately equal during the first 60 minutes of storage. after 60 minutes, the color change of the wrapped sample was slower than the unwrapped sample. At 139 minutes of storage of the wrapped sample and 150 minutes of storage of the unwrapped sample their colors were 4.7 and 3.6 units respectively from their standards. The color of these samples more nearly approximated their standards after 24 hours of storage. The color of the unwrapped sample changed rapidly after 24 hours of storage. The color had darkened enough to be considered unsalable after 87 hours of storage. At this time it was 12.8 units from the standard. After 24 hours, the color of the wrapped sample changed very little until 190 hours of storage. The color change was rapid after 190 hours. At 310 hours of storage the color of this sample was considered unsalable. This is compared with 87 hours when the unwrapped sample was considered unsalable. ~61- Brooks (13) found that discoloration is closely connected with the factors governing the loss of water from the meat. It should be expected that the unwrapped sample would lose moisture faster than the wrapped sample since allen (1) related that the film (300 Mth #80 Du Pont cellophane) used on the wrapped sample has a low water vapor permeability and a wettable surface. From this standpoint, discoloration should be faster on the unwrapped sample. Brooks (13) also found that at 0°C (32°F) the rate of methemoglobin formation was greatest when the partial pressure of oxygen was 4 mm. of mercury. Allen (1) stated that the oxygen permeability of the cellophane used was relatively low. Therefore, if the oxygen pressure in the wrapped package was low, rapid discoloration should have resulted. This did not occur. Lavers (29) found that packaging fresh meat in an oxygen- impermeable film caused rapid discoloration. He found that this was due to a lowered oxygen pressure beneath the film due to diffusion into the meat and bacterial oxygen demand. The results obtained with the wrapped sample are in agreement with results related by Allen (1) where meat wrapped in 300 MSAT #80 cellophane remained bright and salable for seven to nine days. The loss of water from the samples seemed to be more important than the low oxygen pressure in causing the discolor- ation of these samples. Tabular data of these samples are shown in.Appendix C. 2. ‘ =2 ‘ 4 . 4 ‘ e~ 6‘ \\ a“ 8‘ .---_\ \‘\\ o 2 w‘ ii '0‘ 5 ° \ z \ a :2 (9 I- In .2- W l9.“ 2 E 2 c: u FIGURE 5.5- COLOR CHANGE OF WRAPPED AND “- I4“ w W- UNWRAPPED SAMPLES sroaso m In I- DARKNESS I: 5 FROM 2.4 To me HOURS 3 FIGURE 5 -coI.oa CHANGE or WRAPPED MID 2 —;$A:Ibfd:umwam:s°bl :AOMPLES Ie- UNWRADPED SAMPLES 57°89” 'N ‘6‘ ---- TRIAL. H,WPIAPPED SAMPLES I DARKNESS STANDARD I vs 4.0/6.0 ' FROM 5 To ISO MINUTES GUNSALABLE ”“5 7° COLOR K -— TRIAL G,u«uIP.APP£D SHmPLE I6“ STANDARD = IO a 4.0/ 7.0 '8' TRIAL H, WRAPPED ssmPLE STANDARD =I vs 4.0/6.0 10‘ 2°! 22- 2.2." 23 I 23 I I I I I I I I I o 7.0 40 (go 80 I00 I20' I40 I50 24 48 72. 96 I10 I44 I68 I92. ZIG 2.40 264 2.88 3l2. (IV.) Effect of Light Figures 6 and 6a show the effect of light on the color change of fresn meat Stored unwrapped. Tabular data are shown in appendix D. The rate of color change of the samples stored under 215 foot candles of light compared to darkness was approximately the same during the first 120 minutes of storage. Considerable differences were found at 24 hours of storage. The color of the sample stored under 215 foot candles of fluorescent light was more desirable as it was only 3.2 units from the standard. The color of the samples stored under 215 foot candles of incandescent light was Very undesirable as indicated by its being 27 units from the standard. The color of the sample stored in darkness had changed to a less desirable color also. After 24 hours of storage the color of the sample stored in darkness and the sample stored under 215 foot candles of fluorescent light changed at approximately the same rate. The color of the sample stored under 215 foot candles of fluorescent light was considered unsalable after 50 hours of storage compared to 72 hours of storage for the sample stored in darkness and the sample stored under 215 foot candles of incandescent light show little difference (see Appendix D). The initial color attributes of the sample stored under 215 foot candles of fluorescent light were 1.8 hue steps yellower, .43 value steps brighter, and .9 chroma steps weaker than the -54- sample stored in darkness. This difference may be accounted for in the amount of intramuscular fat within the area viewed. A thermometer was placed at the meat surface to determine if the lights were causing an increase in temperature. The light used to supply 215 foot candles of incandescent light caused an increase in temperature of 15°F at the meat surface. The storage room temperature was 34°F so that with the 15°F increase caused by the light, the meat sample storage temperature was 49°F. The temperature of the sample stored under 215 foot candles of fluorescent light was increased 30F above that of the storage room temperature. This sample was therefore stored at a temperature of 37°F. To account for the rapid discoloration of the sample stored under 215 foot candles of incandescent light, the following explanation is offered. as pointed out, incandescent light caused a storage temperature increase of 15°“. Brooks (13) has shown that the depth to which oxygen penetrated the tissue decreased with increasing temperature. Brooks (11) also found that methemoglobin formed directly on or very near the surface darkened the color to a greater extent than the same amount of pigment produced in the same time but some distance below the surface. Therefore, the increase in temperature would cause the formation of methemoglobin to be closer to the surface and consequently a darker color when compared to the sample stored in darkness at the lower temperature. Rikert (43) found that the rate of darkening -55- of unpackaged meat increased with an increase in temperature. The sample also evidenced a loss of moisture. This could account for the dark color of the sample since Brooks (13) has shown that excessive drying causes a dark appearance due to the Optical changes in the tissue. No doubt a combination of these factors caused the rapid discoloration. Comparing the sample stored in darkness with the sample stored under 215 foot candles of fluorescent light, the storage temperature difference was 30F. Other than the color change after 130 minutes, until 24 hours, the change of these two samples was similar. This would indicate that light did not affect the color change of the samples. -66- ‘. s 4.4 4.. ‘. FIGURE 62‘ COLOR CHANGE OF UNWRAPPED _ I. SAMPLES STORED IN DARKNESS .‘ AND TWO SOURCES OF LIGHT . FROM 2.4 To an: nouns ‘. ——TRIAL s DARKNESS 6‘ e- I, ——— TRIRL 6 ms poo-r CANDLES I Incnupesceu'r LIGHT I| -----TR|BL Io :us coo-r CANDLES .. FLUORESCENT LIGHT r .| O UNSALAeLa nu: To COLOR 8' o 8‘ I. N '. g a 3 \ d” I 0_ :04 I0- ‘. st 0‘ ‘. I o . x '- I 9 a 0 ll‘ 5‘: It at o < 2 q - Il - i2“ I, an... ,’ ¢ fl 4 FIGURE 8 COLOR CHANGE or WRADDED SAMPLES a ." STORED UNDER Two INTENSITIES OF 2 . FLUORESCENT LIGHT g d '4 FROM I2. To I35 MINUTES “'4 __.TRIAI. II, 2|5 FOOT CANDLES FLUORESCENT LIGHT S —--- TRIAL 2.0, 60 £001“ mxmaie‘j o FLUORESCENT LIGHT g 16" ”‘6‘ z a 18" 18“ 10‘ 20‘ I. 22 I I I I I ' 1 | 22 100 110 140 O l I10 I I44 T l l I I I I I I j JOB I92. 2K: '140. 264 2.86 .3I1 536 360 384 (V.) EffeCL of Freezing To show the effect of freezing on the color changes, a portion of the wholesale rib cut was frozen and held for a period of 3 weeks at 003. After thawing 2 days at 34°F 8 sample was removed to compare the color changes with a sample from the same cut that had not been frozen. figures 9 and 9a illustrate the results of these samples stored unwrapped in darkness. Tabular data are shown in appendix G. The rate of the color change of the sample whicn had been frozen was much slower than the rate of the color change of the unfrozen sample during the first 120 minutes of storage. The color of the unfrozen sample more nearly equalled that of the standard at 19 hours of storage. after 19 hours of storage the color of the unfrozen sample darkened rapidly. This sample was considered unsalable at 71 hours of storage. The color of the sample that had been frozen increased in desirability until 36 hours of storage. after this, the sample began to darken until it was considered unsalable at 84 hours of storage. after 84 hours the rate of darkening was faster. Brooks (9) found that freezing and thawing of meat appeared to increase the rate of methemoglobin formation compared to control tisaue which had not been frozen. Mangel (31) was unable to verify this, as her samples allowed to thaw from one to five times did not show increased rate of methemoglobin formation. The results presented in figures -734 9 and 9a indiCate that the rate of oxyhemoglobin formation was slower in the sample which had been frozen compared to the unfrozen sample, but the rate of methemoglobin formation (discoloration) was not increased. -74- 4.4 ‘d IOR 4.0/7.0 UNITS FROM $1’AN DARD I COLOR. CIIRNGE OF UNWRAPPED THHWED FRozm SAMPLE COMPARED WITH UN- WRAPPED uumozen SAMPLE. 'FROM 3 To I14 MINUTES '—TRIAL N .FRESH SAMPLE --- TRIAL 1'. THAth menu SAMPLE 41 FIGURE 9a. COLOR CHANGE OF UNWRAPPED THAWED _ FROZEN SAMPLE COM- “ PARED WITH UNFROZEN SAMPLE FROM I). TO Iao HOURS ---TRIAL N, :IImI snmme 8' ----TI\IAL T, THAwso C FROZEN SAMPLE 5 ’r- -~‘ 0 UNSALABLE DUE To COLOR I ‘s n I ~ . [o‘ I V! ’1' Q, d 1' ‘I G ,’ . “ I | a n." ,I' ‘\ I! I 3 'I Z ‘I < “ )- .. m IQ |‘ ’IA‘ 2 ’ ‘I O ‘I g \ “- Ie“ ‘\‘ w \ I- k - \ Z ‘\ \ 3 B— \. 20‘ 22. 2“ T T l I l l I fl 0 2.4 +3 72. 96 no ‘I68 I44 I92 (VI.) Effect of Delayed Wrapping Figures 10 and 10a show the effect of a "blooming period" on the color Change. A pair of samples was cut at the same time. One sample was Wrapped 3 minutes after cutting and the other was wrapped 30 minutes after cutting. These samples were stored under 30 foot candles of white fluorescent light. Tabular data are snown in appendix H. The color of the sample wrapped 30 minutes after cutting did not snow any appreciable Change until 30 hours of storage, whereas the color of the sample wrapped 3 minutes after cutting brightened rapidly during the first hour. after 00 minutes of storage the color of the sample wrapped 3 minutes after cutting was nearly the same as the color of the sample wrapped 30 minutes after cutting. The color of the sample wrapped 30 minutes after cutting was most desirable after 30 hours of storage compared with 82 hours of storage for the sample wrapped 3 minutes after cutting. After 200 hours darkening was noticeable and the rate of the color change of these samples was very similar throughout the remainder of storage. The sample wrapped 3 minutes after cutting was unsalable after 444 hours of storage compared with 420 hours for the sample wrapped 30 minutes after cutting. The Production.& Marketing administration of the United States Department of agriculture (50) suggests that pre- packaged meat retailers allow for a "blooming period" of l5 to 30 minutes after cutting as one of several measures to slow discoloration. The sample wrapped 3 minutes after -70- cutting obtained a desirable color within one hour and remained salable as long as the sample wrapped after 30 minutes. This would indicate that the blooming period does not necessarily prolong salable storage time. -77- -I O— -I 2" 4* 4" o 43 9 \ ND q \ + ' °— 6‘ v O E n: - Z. 6‘ 5‘ a a O < I: q < z o E K" g IO“ D) In E FIGURE IO-COLOR CHANGE OF SAMPLES WRAPPED 5 FIGURE IOU-COLOR CHANGE OF snmmzs WRAPPED \ c: :1— AT DIFFERENT INTERVALS AFTER CUTTING g .3 AT DIFFERENT INTERVALs AFTER CUTTING \\ “ AND STORED UNDER :50 FOOT CANDLES h AND sToRED UNDER so FooT CANDLES a V) OF FLUORESCENT LIGHT ‘0 OF FLUORESCENT LIGHT \ I- ; ,4. FROM 8 To Iso MINUTES £2: 34.. FROM 30 TO 490 HOURS 3 TRIAL II, WRAPPED :5 MINUTES 3 TRIAL II.WRAPPED 3 MINUTES AFTER CUTTING AFTER CUTTING ----- TRIAL Y, WRAPPED 30 MINUTEs ----- TRIAL I, WRAPPED 30 MINUTES AFTER CUTTING . AFTER CUTTING 6‘ _ I 3‘“ GUNSALABLE DUE. TO COLOR ' I \\ \ ‘\ “\ IF“ 18" \L, I I I I I I 1 I 20 I I I I I II I I r I I I I I I I I I l I w 20 4: 60 BC iOO ‘11-} , ‘40 IGO C- 24 48 72. 9G: :10 1+4 Ho: :92. 2.66 .2410 gaff ,3"? «34:5. 33)" 3“ 384' 4'05 +51 45.5 450. 504‘ A second pair of samples from another animal was treated similarly. These samples were stored under 215 foot candles of fluorescent light. The color changes are illustrated in figures ll and lla. Tabular data are shown in.Appendix I. The color of the sample wrapped 3 minutes after cutting indicated a peculiar color change. The color brightened rapidly during the first 35 minutes. at this time the color was brighter than the color of the sample wrapped 30 minutes after cutting. after 35 minutes, the color of the sample wrapped 3 minutes after cutting, showed a slow but steady darkening until 125 minutes of storage. No other sample showed this darkening in color during the first two hours of storage. The sample wrapped after 30 minutes increased in color desirability during this period of storage. The rate of the color change of these samples was very similar after 24 hours of storage. Both samples were considered to be unsalable after 240 hours of storage. These results also indicate that the blooming period was not necessary, as the sample wrapped without a blooming period remained salable as long as the sample wrapped after a blooming period. -79.. 1“ 1‘ FIGURE Ila. COLOR CHANGE OF SAMPLES WRAPPED AT DIFFERENT INTERVALS AFTER CUTTING AND STORED UNDER ~~~.---—\ :45 FOOT CANDLES FLUORESCENT \\ LIGHT if. 4 \\ FROM 24 TO 338 HOURS \ ----TRIAL so,WRAPPEn 3 MINUTES 0 0. \ AFTER CUTTING . \D \ ~o \ q \ ___TRIAI. aI, WRAPPED so MINUTEs \s‘ o 6 \ AFTER CUTTING o ‘ ‘. ' J V \ 0 UNSALABLE. DUE TO COLOR I! ‘ ‘ It >- > 8‘ / " 8‘ — l/ a O /I d d .’ < < O o _ Z - 2 10 < )0 :2 I» h In 2 Eu. 0 liq a: FIGURE II coma CHANCE OF aAwwLES wmwneb E u. AT DIFFERENT INTERVALS AFTER CUTTING w :3 AND STORED UNDER 25 FOOT CANBLE’S t 4 -2- H“ FLUORESCENT LIGHT Z '0’ \ . D 3 FROM 5 To I38 MIN UTES """' TRIAL 30 ,WRAPPED 3 MINUTES AFTER CUTTING _ TRIAL 3| , WRAPPED so MINUTES AFTER CUTTING 20 I I I l 5 I 2.0 I I I I I I I I T ‘I I I I » r 1 0 22> 4'0 so r50 :00 Ian ’ [4'0 0 .24- 48 71 96 I10 144' I65 I92. 2.16 240 .164 .286 3+2. 334. 360 aw A third pair of samples was treated similarly and stored in darkness. The color changes of these samples are illustrated in figures 12 and 12a. Tabular data are shown in Appendix.J. The rate of color change of these samples was nearly equal until 150 minutes of storage. The color of the sample wrapped 30.minutes after cutting was most desirable at 24 hours of storage. The color of this sample then decreased in.desirability as storage time continued. This change was slow until 163 hours of storage, after which the rate in, creased. The color of the sample wrapped.5 minutes after cutting did not obtain its maximum desirability until 120 hours of storage. There was little change in the color after 80 hours until 144 hours. Darkening began after 144 hours and the rate of color change was approximately equal to that of the sample wrapped 30 minutes after cutting. The color of both samples was rapidly approaching an.unsalable color at the end of storage, about 300 hours. The results from this pair of samples again indicate that the sample wrapped 30 minutes after cutting obtained its most desirable color sooner than the sample wrapped 5 minutes after cutting. However, comparing the color of the two samples at equal times after cutting showed little difference in color. The color of the sample wrapped 5 Minutes after cutting was as desirable as the sample wrapped 30 minutes after cutting at the end of storage. -81- IYR 4.0/"5.0 UNITS FROM STANDARD 8'4 38" 2.0 COLOR CHANGE OF SAMPLES WRAPPED AT DIFFERENT INTERVALS AFTER CUTTING AND STORED IN DARKNESS FROM Io TO ISO MINUTES ----TRIAL I, WRAPPED 3 MINUTES AFTER CUTTING --—-' TRIAL .T. WRAPPED 30 MINUTES AFTER CUTTING FIGURE l2 UNITS FROM STANDARD IYR 4.0/so 6‘ I (D A '5 J p L 3 I FIGURE Ila COLOR CHANCE OF SAMPLES WRAPPED AT DIFFERENT INTERVALS AFTER cUTTINC. AND STORED IN DARKNESS FROM 2.4 To 308 I-IouRs ----TRIAI. I .WRAPPED 3 MINUTES AFTER CUTTING ...—TRIAL :r,WRAPPED 30 MINUTES AFTER CUTTING ' 0 UNSALABLE DUE TO COLOR I I I I I I I v I I I I 14» 43 72. 96 I10 III-4 I68 I92. 1H: To determine the effect of freezing on the color change of wrapped samples, a portion of the same rib cut, from which the samples illustrated in figures 12 and 12a were obtained, was frozen 3 weeks at 00F. After thawing 2 days at 34°F, samples were removed and wrapped at different times to determine if a blooming period delayed discoloration of samples which had been frozen. The results are shown in figures 13 and 13a. The initial rate of the color change of the thawed samples which had been frozen was approximately the same as the initial rate of the color change of the unfrozen sample (compare figures 12 and 12a with 13 and 13a). After 24 hours, however, the samples which had been frozen, regardless of time of wrapping after cutting, all darxened in color much faster than the unfrozen samples. The blooming period on the samples which had been frozen did not increase the salable storage time. The sample wrapped 60 minutes after cutting was considered unsalable after l48 hours of storage compared with 172 hours of storage for the sample wrapped 30 minutes after cutting and lo3 hours for the sample wrapped 4 minutes after cutting. Comparing these periods with the unfrozen samples in figures 12 and 12a, the samples which had been frozen were unsalable much sooner. Brooks (9) and Mangel (31) have reported conflicting results on the effect of freezing and thawing of meat on the rate of methemoglobin formation. Brooks (9) found that this -53- 'increased the rate of methemoglobin formation while Mangel (31) found that it did not increase the rate of methemoglobin formation. The results of the unwrapped thawed frozen sample (illustrated in figures 9 and 9a) previously discussed indicated that freezing and thawing did not increase the rate of methemoglobin formation. The results of the wrapped thawed frozen samples illustrated in figures 13 and 13a indicate that the freezing and thawing did increase the rate of methemoglobin formation when these are compared to wrapped unfrozen samples illustrated in figures 12 and 12a. Tabular data of these samples are shown in.Appendix K. IYR 4.0 /6.o UNITS FROM STANDARD .4 8‘ .11 .—-- ..-—-0 I I I I I I I I l.- —-.———_—f’ x" / ______ / ’x.‘ // /.€>‘I\I ///._’—~/ /'/,/" FIGURE 13 COLOR CHANCE OF THAWED. FROZEN SHMI’LES WRAPPED AT DIFFLRENT’ IN- TERVALS AFTER CUTTING AND STORED IN DARKNESS FROM IO To I55 MINUT’ES —-- TRIAL Y, WRAPPED 4- MINUTES h‘FT’ER CUTTING. ----- TRIAL R,WR&PPED 30 MINUTES AFTER OUTTING -—--— TRIAL w, wRAPPED so MINUTE$ AFTER- cmmc' (so 80 IOO I20 “IO [80 IYR 4.0/so UN ITS FROM STANDARD 1'1 4'4 6‘ 20‘ FIGURE ISA Co LOP. CHANCE OF THAWED FROZEN SAM PLES WRAPPED AT DIFFERENT INTERVALS AFTER CUTTING AND STORED IN DARKNESS. \ FROM 2.8 To 340 HOURS I - __TRIAL. v, WRAPPED 4 . I MINUTES AFTER CUTTING ....... TRIAL R, WRAPPED 30 MINUTES AFTER CUTTING TRIAL w, WRAPPED so MINUTES AFTER CUTTING I, 0 UNSALABLE Due To COLOR 2.1 I I I I_ I f I I I r I I I j 14 48 71 96 I10 III} (68 I91 346 2.4-0 .294 2.88 an. 335 Pt. ii . , ‘1‘ ‘L r v V 1,. h . , V. DD AIL: - u'iiiY The application of disk colorimetry as an obgective measurement of color changes of fresh beef muscle has been presented. Color differences were found in the longissimus dorsi muscle of different animals. Differences were also noted in different areas of the same sample. aging of the rib portion before cutting the steak samples did not alter the rate of the color change. Under similar conditions of storage, samples wrapped in Du Pont 300 MSAT #80 cellophane maintained a salable color longer than unwrapped samples. Many wrapped samples maintained a salable color in excess of 10 days. It should be noted, however, that there was no stacking and handling of the samples after placing in storage. Under the conditions of this study the samples brightened rapidly during the first two hours after cutting. The color change of the samples was approximately twice as great during the first one hour as it was during the second hour. Subsequent desirable color changes occurred at a slower rate. The intensities of light employed did not affect the rate of color change of unwrapped samples under comparable storage temperatures. sources of light that increased the storage temperature reduced the salable storage time of -50- both wrapped and unwrapped samples. Freezing and thawing of the rib cut before cutting the steak samples reduced the salable storage life of wrapped samples. This did not, however, reduce the salable storage life of unwrapped samples. a blooming period before wrapping did not extend the salable storage life when compared with samples wrapped immediately. It did, however, shorten the time necessary for the development of optimum color. T BIBLIOGRAPHY lO. BanlQGRAPHY Allen, N. 1949 Rest Film Consideration. modern raCkaging. January 1949. Anonymous 1946 Self-Service Meat. E. I. Du Pont de Kemours and Company, Wilmington, Delaware. 45 pp. anonymous 1945 How To Prepackage Meat. E. I. Du Pont de Nemours and Company, Hilmington, Delaware. 24 pp. Anonymous 1949 Housewives Prefer Self-Service, USDA Survery Shows; Some Shoppers Miss Personal Contacts. The National Provisioner, 121: December 25:19. Anonymous 1949 Prepackaged Self-Service Meats. 1949 Report, Armour & Company. 31 pp. Anonymous 1950 Boon Continues, Survey Shows. Reported by Armour & Company in The National Provisioner, 122: June 23:14. Anonymous 1950 More Meats, Other Items Sold in Super Markets Having 100% Prepak Meat Units, Survey Shows. The National Provisioner, 122: March lO:40. Baker, Jim 1949 Packaging Problems and Solutions. Reprint of a speech presented at the National Independent Meat Packers Association meeting reported in The National Provisioner, 120: June 23:120-142. Brooks, John 1929 Post-mortem Formation of Methemoglobin in Red Muscle. Biochemicangournal, g3: 1391-1400. Brooks, John l93l The Oxidation of Hemoglobin to Methamoglobin by Oxygen. Proceedings of the Royal Society of London, (BI, 199: 35Q50. 12. 13. l4. 15. lo. 17. BI‘OOKS , 50m 1933 The Effect of Carbon Dioxide on the Color Changes or Bloom of Lean Meat. Journal of the Society of Chemical Industry, 52: l7T-19T. Brooks, John 1935 The Oxidation of Hemoglobin to Hethemoglobin by Oxygen. II. The Relation Between the mate of Oxidation and the Partial Pressure of Oxygen. Proceedings of the Boyal Society of London, (E), llé: 500. Brooks, John “ 1937 Color of Heat. Food Research, 3: 75-77. Brooks, John - 1946 The Oxidation of Hemoglobin to Methemoglobin by Oxygen. Journal of Physiology, 107: 332-335. Chamberlain, C. C. and Bratzler, L. J. 1946 Report on Hope-Elannagan ProJect l-A, 1947-1948, Michigan Agricultural fixperiment Station, Animal Husbandry Department, mimeographed publication. 13 pp- Chang, I. and Watts, B. n. 1949 Antioxidants in the Hemoglobin Catalyzed Oxidation of Unsaturated Fats. Food Technology, 3: 332. Gilchrist, F. W. 1948 An Analysis of Pre-Packaged and Self-Service as a means of Lowering Costs of Retailing Meat and Delicatessen Products. A copy of a dissertation presented to the faculty of the Department of ,Economics, University of Southern California, . Los Angeles, June, 1945. 10 pages. GilChriSt, 5‘9 1:510 1949 Self-Service Retailing of Meat. The Journal of Marketing, 13(3): 295-304. Gowland, J. S. 1949 Technical and Operational Prcblems of Self-Service Meat Merchandising. Michigan State College Thesis, typewritten publication. 58 pages. Haurowitz, Felix 1950 Chemistry and Biology of Proteins. academic Press Inc. New York, new York. 374 pp. -89- 27. 3o. 31. Hoagland, n. Coloring Matter of Raw and Cooked salted meats. Journal Agricultural Research, 3: 211. 1915 Jensen, 1949 Kennedy, R. P. and Whipple, G. The Identify of Muscle 1926 L. B. microbiologywof Heats. Cilainliaaign, 36‘] PE. The Garrard Press, v 7. P: ML. Hemoglobin and Blood Hemoglobin. American Journal of Physiology, 7o: bOj-0920 Kraft, A. A. and sanderstock, J. J. meat Color Problem is Closer to Solution. Food 1950 Kralile I‘ , 1949 Kramer, 1951 Kraner, 1952 Industries, 22(1): 65. R. C. Consumer Response to Prepackaged Fresh Keats. Kichigsn Agricultural Experiment 3tation_;uarter1y Bulletin, 32(1): l2—lo. R. C. An.Economic Analysis of Prepackaged Heat. merchandising with Particular amphasis Upon Sales, Consumer Reaction, and Operational Sfficiency, michigan State College Thesis, typewritten publication. R. C. Increasing Labor Efficiency in Prepackaging Meat. Himeographed copy of Journal Article E0. 1322, Hichigan Agricultural Experiment Station. 7 pages. Kraybill, H. R. New Developments in Meat Products. Food Technology, 1951 Levers, 5: 4550 C. G. 1948 Discoloration of Packaged fled Heat. modern Packag- igg, 21(5): January 1948. Lemberg, R., Legge, J. W., and Lockwood, W. H. Coupled Oxidation of Ascorbic Acid with Hemoglobin. Biochemical Journa1, 33: 754. 193 Mangel, 1951 Margaret The Dete*mination of Methemoglobin in.Beef Muscle Extracts. I. A study of the Spectrophotometric method. 11. Factors affecting hethemoglobin Formation in Frozen Beef. University of missouri Research Bulletin 474. o- 24 pages. 34. 3o. 37- 39. 40. Millikan, G. A. 1939 Muscle hemoglobin. Physiological Reviews, 19: 503-523- Ioran, T. 1935 Post-Hortem and Refrigeration Changes in Heat. Journgl of the Society of Chemical Industry, 5i: 149T-151T. Neill, James H. 1925 Studies on the Oxidation-Reduction of Hemoglobin to Mathemoglobin. I. The Changes Induced by Pneumococci and by Sterile animal Tissue. Journal ongxperimental Medicine, 41: 299-313. Neill, James M. 1925 Studies of the Oxidation-Reduction of Hemoglobin to hethemoglobin. II. The Oxidation of Hemoglobin and seduction of Hethemoglobin by anaerobic Bacilli and by Sterile Plant Tissue. Journal of ggperimental Medicine, 1;; 535-549. Neill, James M. 1925 Studies on The Oxidation-heduction of Hemoglobin and Methemoglobin. 111. The Formation of Methemoglobin during the Oxidation of Autoxidizable Substances. Journal of Experimental Medicine, $1: 551-560. Neill, James M. 1925 Studies on the Oxidation-heduction of Hemoglobin and Hethemoglobin. IV. The Inhibition of "Spontaneous“ Methemoglobin Formation. Journal of Experimental Medicine, 1;: Sol-570. Neill, James M. and Hastings, A. B. 1925 The Influence of the Tension of Molecular Oxygen Upon Certain Oxidations of Hemoglobin. Journal of Biological Chemistry, Q3: 479. Nickerson, Dorothy 1946 U. S. Department of Agriculture. Colorjgeasurement and Its Application to the Grading of agricultuggl Products. Washington: Government Printing Office, 1946. 02 pp. Hamsbottom, J. M. 1947 Freezer Storage Effect on Fresh heat Quality. Refrigerating Engineering, 53: 19-23. -91- 41. 43. 4b. 47. 48. 50. 51. Ramsbottom, J. m. and Koonz, C. a. 1941 Freezer Storage Temperature as Related to Drip and to Color in Frozen-Defrosted beef. Food Researcn, Q: 571-500. Rants, R. R. 1951 an analysis of Consumer Reaction to rrepacxaged Meat. Michigan State College Thesis, typewritten publication. 173 pages. hiKeI‘t, J. A. 1952 Color Changes of Fresh Meats as Influenced by Some Antioxidant, Temperature and Atmospheric Variations Rutgers University Thesis, typewritten publication. >7 pasES- Shenx, J. H., Hall, J. L., and Ring, H. H. 1934 Spectrophotometric Characteristics of Hemoglobin. 1. Beef Blood and Muscle Hemoglobins. Journal of Biological Ciemistry, 105: 741-752. Teitelman, Sam 194s fire-PackagedJgelf-Service Meats. armour & Company, Chicago. 36 pp. Teitelman, Sam 1949 Self-Service Meats. The National Provisioner, 120: May 14:3o. Teitelman, Sam 1949 Packer Survey Trends in Self-Service Meats. The National Provisioner, 120: May 21:15. Teitelman, Sam 1949 Ere-Eachaged Self-Service Meats. armour & Company, Chicago. 31 pp. U. S. Department of Agriculture. Retailing Prepackaged Meats. Washington: Government Printing Office, 1949. 27 pp. U. S. Department of Agriculture. Costs of and Reasons for RewrappinggPrepackaged Meats, Poultry and Cheese. Washington: Government Printing Office, 1951. 34 pp. Vestling, S. 1941 The Reduction of Methemoglobin by Ascorbic acid. Proceedings of the American Society of Biological Chemistry in.Journa1 Biological Chemistry, 140: 135. v r -94- 53. 54. 55- 56. 58. Voegeli, M. M. 1950 Flow Sheets of frepackaged Fresh heat. Michigan State College Thesis, typewritten publication. 9o pages. Watson,.Rodger H. 1935 CCLII. Some Observations on the Estimation of muscle Hemoglobin. Biochemical Journal, 29(2): 2114-2121. Watts, B. M. and Lehmann, B. T. 1952 The Effect of ascorbic acid on the Oxidation of Hemoglobin and the Formation Nitric Oxide Hemoglobin. Food Research, 12: 100-106. Whipple, e. H. 7 1920 The Hemoglobin of Striated Muscle. I. Variations . Due to Age and Exercise. american Journalyof gt Physiology, Zé: 693-707. Whipple, G. H. 1926 The Hemoglobin of Striated Muscle. II. Variations Due to Anemia and Paralysis. American.Journal of Physiology, zé: 706-714. fliesman, C. K. 1947 Packaging Supplies, Equipment, and Product Care of Meats for Retail Self-Service. Armour & Company, mimeographed publication, 12 pages. fliesman, C. K. and Hagen, R. F. 1949 Technical Aspects of Self-Service Meats. armour & Company, mimeographed publication, 21 pages. -93... AP Prllfl') IX Wrapped Sample Stored in.Darkness Trial 21 - Average Prime 2 Year Old.Ang us Steer Cutting temperature - 64°F, Cooler temperature - 34°F Standard IYR 4. O/o.O Time of Reading Units from _§£;er Cutting Hue Value Chroma Standard 10 Minutes 4.3ra 4.06 3.7 12.4 20 " 4.0YR 3.98 4.1 10.6 30 " 3.7YR 4.0 4.2 9.9 40 " 3.313 4.0 4.4 8.8 55 " 3.1YR 4.06 4.5 8.9 70 " 2.3YR 4.21 4.7 7.5 85 " 2.1YR 4.23 4.8 6.9 100 " 1.9YR 4.25 4.9 6.9 115 " 1.9YR. 14.25 4.9 6.9 130 " 1.713 4.26 5.0 6.2 244 Hours 1.713 4.42 5.5 5.4 68 " 2.0YR 4.61 5.4 7.6 95 " 3.1ra 4.43 5.1 9.4 121 " 2.8YR 4.40 4.6 9.9 144 a 3.913 4.32 4.1 12.3 168 " 8.0ya 4.23 2.9 18.6* 192 " 9.4111 4.18 2.6 20.1 * Unsalable -94- APPENDIX A - continued Wrapped Sample Stored in.Darkness Trial 8 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 2 weeks after slaughter Cutting temperature - 64°F, Cooler temperature - 33°F Wrapped 3 minutes after cutting Standard 1Y3 4.0/6.0 Time of Reading Units from after Cutting, Hue Value Chroma Standard 6 Minutes 2.9YR 3.50 4.3 11.4 16 " 1.9YR 3.58 4.7 8.0 26 " 1.713 3.61 4.8 7.3 36 " 1.6YR 3.63 4.9 6.9 51 " 1.4YR 3.65 4.0 5.6 66 " 0.9YR 3.69 5.3 4.1 81 " 0.9YR 3.69 5.3 4.1 96 " 1.1xa 3.56 5.7 3.5 111 " 1.8YR 3.71 5.8 4.3 126 * 1.8YR 3.71 5.8 4.3 30 Hours 0.6YR 3.96 6.1 1.3 78 " 10.0R 4.23 6.0 3.6 102 " 0.4YR 4.09 6.0 2.0 126 " 0.6YR 3.96 6.1 1.3 150 " 1.1YR 3.90 5.9 1.1 174 " 1.4YR 3.87 5.7 2.4 196 ' 1.4YR 3.85 5.6 2.7 220 " 1.2YR 3.96 5.4 2.2 244 " 1.8YR 3.98 5.8 2.5 268 " 2.2YR 3.94 5.6 4.5 -95- ArPENDIX A - continued Trial 8 - continued Time of Reading Units from after Cutting Hue Value Chroma Standard 292 Hours 2.1YR 3.77 5.1 6.1 316 " 3.813 3.89 4.4 10.3* 340° " 5.1xa 3.79 3.9 13.9 364 " 7.4YR 3.68 3.3 18.3 * Unsalable -96- Unwrapped Sample Stored in.Darkness APPENDIX B Trial B - Low Choice 16 Month Old Hereford Steer Sample cut from rib 1 week after slaughter Cutting temperature - 64°F, Cooler temperature - 36°F Standard 10R 4.0/7.0 Time of Reading Units from after Cutting, Hue Value Chroma Standard 3 Minutes 3.413 4.2 3.6 16.2 18 " 2.613 4.3 4.4 14.2 23 " 2.113 4.4 4.7 13.2 33 u 1.513 4.4 4.9 11.6 43 H 1.613 4.3 4.7 11.7 53 a 1.613 4.3 4.7 11.7 63 a 1.412 4.3 4.8 11.1 93 " 1.113 4.2 5.1 9.1 123 " 1.113 4.2 5.1 9.1 153 v 0.913 4.3 5.4 8.5 183 " 0.9YR 4.3 5.4 8.5 268 " 1.21s 4.1 5.3 8.2 373 " 0.3YR 4.1 5.5 2.8 -97- Unwrapped Sample Stored in Darkness APPEHDIX B - continued Trial F - Low Choice 18 honth.Old Hereford Steer Sample cut from rib 2 weeks after slaughter Cutting temperature - 65°F, Cooler temperature - 34°F Standard 103 4.0/7.0 Time of Reading Units from after Cuttgng Hue Value Chroma Standard 3 Minutes 4.713 4.1 3.3 17.9 13 " 3.513 4.1 3.7 15.7 28 " 2.613 4.2 4.1 14.2 33 " 2.313 4.2 4.2 13.5 43 " 1.913 4.2 4.7 11.7 53 " 1.713 4.2 4.8 11.1 63 a 1.713 4.2 4.8 11.1 83 " 1.513 4.1 5.5 8.4 113 * 0.413 4.1 5.4 6.3 152 " 0.313 4.0 5.8 4.3 242 " 0.613 3.9 6.1 4.8 302 " 0.213 4.0 6.4 2.3 362 " 0.213 4.0 6.4 2.3 ._ ”w. APPENDIX B - continued Unwrapped Sample Stored in.Darkness Trial 0 - Low Choice 15 Month.01d Hereford Steer Sample cut from rib 4 weeks after slaughter Cutting temperature - 60°F, Cooler temperature - 32°F Standard 10R 4.0/7.0 Time of Reading Units from after Cuttgng Hue Value Chroma Standard 5 Minutes 5.2YR 4.56 3.8 21.1 20 “ 4.0YR 4.46 4.5 17.7 30 " 3.513 4.41 5.0 15.4 40 a 3.513 4.33 5.3 14.3 50 " 2.7YR 4.27 5.3 12.6 60 " 2.313 4.32 5.6 11.2 70 " 2.0YR 4.34 - 5.7 10.3 80 " 1.4YR 4.28 5.7 8.9 90 " 1.413 4.28 5.7 8.9 100 " 1.013 4.33 6.0 7.2 120 " 1.113 4.23 6.2 6.3 140 " 1.213 4.14 6.6 6.8 260 " 1.013 4.16 6.7 4.8 394 a 0.413 4.04 7.2 1.8 APPENDIX C Unwrapped Sample Stored in Darkness Trial G - Low Choice 18 month Old Hereford Steer Sample cut from rib 3 weeks after slaughter Cutting temperature - 64oF, Cooler temperature - 35°F Standard 10R 4.0/7.0 Time of Reading Units from after Cutting_ Hue Value Chroma Standard 5 minutes 5.11R 4.2 3.5 18.8 10 " 4.313 4.1 3.9 16.6 20 " 3.413 4.1 4.6 14.1 30 " 2.613 4.1 4.9 12.0 40 " 2.131 4.2 5.2 11.0 50 " 2.413. 4.1. 5.4 10.6 60 " 2.113 4.1 5.6 9.5 70 " 1.813 4.0 5.4 8.7 90 v 1.613 3.9 5.8 7.9 110 " 1.613 4.1 6.2 7.0 150 " 1.713 4.0 6.4 3.6 233 Hours 9.83 3.8 7.0 1.8 283 u 9.63 3.7 7.5 4.5 303 u 9.23 3.6 7.5 6.3 55 n 8.53 3.4 7.1 8-2 79 " 9.33‘ 3.2 6.2 8.9 87 " 7.93 3.1 6.3 12.8* 111 u 7.23 2.8 5.8 16.3 135 n 7.93 2.6 4.8 19.0 159 u 8.43 2.5 4.1 20.3 183 u 9.83 2.3 3.1 22.2 * Unsalable -lOO- 1'1PPE1‘DL‘C C Wrapped Sample Stored in.Darkness Trial H - Low Choice 18 Month.01d Hereford Steer Sample cut from rib 3 weeks after slaughter Cutting temperature - 65°F, Cooler temperature - 35°F Wrapped 4 minutes after cutting Standard 113 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 9 minutes 3.81R 3.9 3.9 11.3 19 N 3.613 3.9 4.0 10.8 29 N 3.213 4.0 4.3 8.8 39 N 2.913 4.1 4.7 8.1 49 N 3.013 4.0 5.0 7.0 59 N 2.413 4.1 5.3 5.7 o9 N 2.413 4.1 5.3 5.7 79 N 2.413 4.1 5.3 5.7 99 N 2.413 4.1 5.4 5.4 119 N 2.213 4.1 5.5 4.7 139 N 2.213 4.1 5.5 4.7 24 Hours 1.9YR 4.1 5.6 3.8 27 N 1.713 4.1 5.7 3.1 53 N 1.513 4.2 5.7 2.7 78 N 1.513 4.2 5.7 2.7 102 N 1.713 4.1 5.7 3.1 118 N 1.713 4.1 5.7 3.1 142 N 2.313 4.3 5.8 3.1 166 N 1.313 4.3 5.8 3.1 N 1.913 4.0 5.8 2.7 190 -101- APPEIDIX C - continued Trial H - continued Time of Reading Units from after Cutting Hue Value Chroma Standard 244 Hours 2.713 3.8 4.9 7.8 262 " 2.7YR 3.8 4.9 7.8. 286 N 3.313 3.7 4.8 9.8 310 " 4.01R 3.7 4.7 11.3* * Unsalable -102- 13.1313231fo IA D Unwrapped Sample Stored in Darkness Trial 5 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 2 weeks after slaughter Cutting temperature - 64°F, Cooler temperature - 33°F Standard 10R 4.0/7.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 10 Minutes 3.213 3.89 4.0 14.7 20 N 2.113_ 3.98 4.6 11.1 30 N 1.513 3.92 5.1 9.3 40 N p 1.413 3.85 5.6 7.9 55 N 1.413 3.85 5.6 7.9 70 N 1.113 3.88 5.8 6.8 85 N 1.113 3.90 5.9 6.5 100 N 0.913 3.92 6.0 5.8 115 N 0.813 3.94 6.1 5.3 130 N 0.613 3.96 6.1 4.2 24 Hours 8.23 3.58 6.9 7.7 48 N 7.43 3.40 6.6 11.7 72 N 7.63 3.25 7.0 11.9* 96 N 6.43 3.21 6.4 15.8 120 N 7.03 2.97 6.3 15.7 144 N 7.23 2.80 5.8 17.3 168 N 7.53 2.71 5.3 18.2 192 N 7.93 2.62 4.9 18.8 216 N 7.73 2.72 3.8 20.9 * Unsalable -103- APPENDIX D - continued Unwrapped Sample Stored in Light Trial 10 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 4 weeks after slaughter Cutting temperature - 65°F, Cooler temperature - 34°F 215 foot candles white fluorescent light Rise in temperature at meat surface due to light 30F Standard 10R 4.0/7.0 Time of Reading Units from after Cutting Hue Value Chroma Standard_ 4 Minutes 5.0YR 4.32 3.1 19.7 14 N 4.213 4.48 3.7 18.1 24 N 3.213 4.36 4.4 15.8 34 N 2.813 4.40 4.6 14.8 49 N 2.513 4.43 4.8 13.8 64 N 2.413 4.36 5.1 13.0 79 N 2.013 4.38 5.2 12.0 94 N 1.713 4.41 5.4 10.9 109 N 1.713 4.41 5.4 10.9 124 N 1.713 4.42 5.5 10.6 25 Hours 9.9R 3.86 6.2 3.2 50 N 7.93 3.26 5.9 12.5* 73 N 7.93 3.41 4.6 14.7 106 N 8.63 3.46 3.8 14.7 130 N 9.43 3.41 ' 2.9 16.0 154 N 7.93 3.47 2.5 18.6 178 N 9.23 3.05 1.9 21.3 N Unsalable -lO4- APPENDIX D - continued Unwrapped Sample Stored in.Light Trial 6 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 2 weeks after slaughter Cutting temperature - 64°F, Cooler temperature - 33°F 215 foot candles incandescent light Rise in temperature at meat surface due to light lSOF Standard 103 4.0/7.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 9 Minutes 3.5YR 3.75 4.1 15.6 19 N 2.413 3.73 4.9 12.8 29 " 1.9YR 3.67 5.6 10.3 39 N 1.813 3.71 5.8 9.6 54 N 1.613 3.75 6.0 8.0 69 " 1.4YR 3.66 6.5 6.9 84 N 1.213 3.70 6.7 5.9 114 N 0.513 3.60 6.7 4.6 129 N 0.413 3.62 6.8 4.1 23 Hours 6.5R 2.10 3.4 27.0* * Unsalable -105- APPENDIX E Wrapped Sample Stored in Light Trial 7 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 2 weeks after slaughter Cutting temperature - 64oF, Cooler temperature - 33°F Wrapped 3 minutes after cutting 215 foot candles incandescent light Rise in temperature at meat surface due to light 15°F Standard 1Y3 4.0/6.0 Time of Reading Units from after Cutting. Hue Value Chroma Standard 10 Minutes 3.813 3.44 3.8 14.5 20 N 3.113 3.36 4.6 11.7 30 N 2.513 3.41 4.8 10.1 40 N 2.513 3.41 4.8 10.1 55 N 1.713 3.50 5.2 6.9 70 N 1.613 3.52 5.3 6.4 85 N 1.613 3.52 5.3 6.4 100 N 1.413 3.54 5.4 5.7 115 N 1.113 3.56 5.7 3.4 130 N 1.113 3.56 5.7 3.4 31 Hours 0.9YR 3.38 5.2 6.2 55 N 2.013 3.37 4.0 11.2* 79 N 5.013 2.79 2.6 21.6 103 N 5.213 2.76 2.5 21.9 * Unsalable -lOb- anHNDIX E - continued Wrapped Sample Stored in Light Trial 12 - High Commercial 2 Year Old Hereford Steer Sample cut from rib 4 weexs after slaughter Cutting temperature - 65°F, Cooler temperature - 34°F Wrapped 4 minutes after cutting 215 foot candles white fluorescent light Rise in temperature at meat surface due to light 30F Standard 1Y3 4.0/6.0 Time of Reading Units from after Cutting; Hue Value Chroma Standard__ 9 Minutes 4.0YH 3.98 4.1 10.6 19 N 3.013 3.94 4.7 8.3 29 N 2.713 3.98 5.0 6.4 39 " 2.4YR 3.90 5.4 5.4 54 “ 2.4YR 3.92 5.5 5.2 69 N 2.213 3.94 5.6 4.5 84 N 1.913 3.96 5.8 2.7 99 " 1.613 3.83 5.5 4.0 114 N 1.413 3.87 5.7 2.4 129 " 1.1YR 3.90 5.9 1.1 25 Hours 2.4YR 4.17 5.6 5.5 59 " 2.4YR 3.92 5.5 5.2 83 N 3.113 4.00 5.4 6.3 107 N 3.013 3.94 4.8 8.0 155 N 3.013 3.94 4.7 8.3 179 " 3.5YR 4.02 4.3 9.4 216 N 5.013 4.06 4.1 12.9 274 N 5.713 4.00 3.7 13.9* 298 N 7.013 3.95 3.5 I 15.9 322 N 9.013 4.08 3.2 19.2 346 N 9.613 4.07 3.0 19.9 * Unsalable [4.1" PbNDIX F Wrapped Sample Stored in Light Trial 20 - Average Prime 2 Year Old.Angus Steer Cutting temperature - 65°F, Cooler temperature - 34°F Wrapped 7 minutes after cutting 60 foot candles white fluorescent light Hise in temperature at meat surface due to light l-2°F Standard IYR 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Standa£d_ 15 Minutes 4.3YR 3.57 4.1 13.5 25 N 4.013 3.61 4.3 12.7 35 N 3.413 3.65 4.5 10.6 45 N 2.713 3.69 4.7 8.9 60 N 2.413 3.73 4.9 7.8 75 " 2.3YH 3.75 5.1 6.6 90 N 1.813 3.79 5.4 4.7 105 N 1.813 3.81 5.4 4.7 120 N 1.813 3.81 5.4 4.7 135 N 1.813 3.81 5.4 4.7 25 Hours 2.413 4.17 5.6 5.5 58 N 2.813 4.23 5.1 7.6 95 N 3.613 4.16 4.7 10.0 121 N 3.913 4.02 4.7 9.4 144 N 5.513 3.91 4.0 13.8 168 N 6.113 3.87 3.8 15.0* 192 N 6.613 3.72 3.5 17.1 216 N 9.213 3.72 2.7 20.6 * Unsalable -lO8- 33333311 F - continued Wrapped Sample Stored in Light Trial 11 — Average Prime 2 Year Old nngus Steer Cutting temperature - 65°F, Cooler temperature - 34°F Wrapped 5 minutes after cutting 215 foot candles White fluorescent light Rise in temperature at meat surface due to light 30F Standard lYH 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 12 Minutes 3.413 3.81 4.8 9.4 22 N 2.813 3.87 5.3 6.5 32 N 2.413 3.90 5.4 5.4 42 N 2.413 3.90 5.4 5.4 57 N 2.313 3.82 5.9 4.6 72 N 2.313 3.85 6.0 3.7 87 N 2.013 3.86 6.1 3.3 102 N 1.813 3.90 6.3 3.5 117 N 1.613 3.92 6.4 3.3 132 N 1.613 3.92 6.4 3.3 26 Hours 2.4YR 3.92 5.5 5.2 60 N 3.013 3.94 4.7 8.3 84 " 3.1YH 3.83 5.0 8.4 108 N 3.513 3.79 4.8 9.6 156 N 3.013 3.79 4.3 9.7 180 N 3.513 3.75 4.1 11.0 218 N 4.613 3.93 3.8 12.7 276 " 5.1YR 3.91 3.7 13.6 300 N 6.113 3.87 3.8 15.0* -109- APPENDIX Trial 11 - continued Time of Reading F - continued Units from after Cutting_ Hue Value Chroma Standard 324 Hours 6.513 3.85 3.8 15.6 348 " 7-0YR 3-95 3-5 15.9 372 " '7-33fR 3-93 3-5 15-9 396 N 8.513 3.88 3.2 18.6 * Unsalable -llO- APPENDIX G Unwrapped Sample Stored in.DarKness Trial N - Low Choice lb Month Old Hereford Steer Sample cut from rib 4 weeks after slaughter Cutting temperature - 64°F, Cooler temperature - 32°F Standard 103 4.0/7.0 Time of Reading Units from after Cutting. Hue Value Chroma Standard 4 Minutes 4.513 4.37 3.3 19.4 14 " 2.8YH 4.39 4.2 15.5 24 " 2.9YH 4.31 4.3 14.9 34 N 2.313 4.26 4.9 12.6 44 " 2.1YH 4.29 5.0 12.0 54 " 1.7YH 4.33 5.3 10.5 64 N 1.313 4.36 5.5 9.7 74 " 1.3YH 4.37 5.5 9.7 84 N 0.913 4.39 5.7 8.4 94 " 0.518 4.22 5.9 5.7 104 " 0.5YR 4.22 5.9 5.7 114 N 0.513 4.23 5.9 5.7 124 N 0.413 4.25 6.0 5.8 19 Hours 9.13 3.85 7.4 4.5 26 “ 0.53 3.76 7.4 6.8 71 " 7.63 3.20 6.9 11.7* 91 " 6.68 3.01 6.6 16.2 115 " 7.13 2.84 5.9 17.3 * Unsalable APPHNDIX G - continued Unwrapped Thawed Frozen Sample Stored in.Darkness Trial T - Low Choice 18 Month Old Hereford Steer Sample cut from rib 9 weeks after slaughter Frozen 3 weeks (5-8), Thawed 1 week Cutting temperature 70°F, Cooler temperature - 34°F Standard 103 4.0/7.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 3 Minutes 7.7YH 4.35 3.6 23.7 13 N 6.313 4.32 4.0 20.9 23 " 5.4YR 4.47 4.6 20.1 33 " 5.0YH 4.50 4.8 19.2 48 N 4.613 4.53 5.0 18.2 63 N 4.513 4.46 5.2 17.8 78 " 4.5YR 4.46 5.2 17.8 93 " 4.0YR 4.36 5.4 17.1 108 N 4.613 4.36 5.4 17.1 123 " 4.3YR 4.39 5.0 16.2 12 Hours 2.9YR 4.40 6.1 12.2 36 " 1.0YH 3.72 5.8 9.1 60 " 1.6YR 3.83 5.5 9.2 84 N 0.613 3.41 5.3 10.0* 108 " 2.5YH 3.52 4.4 15.2 132 " 1.3YH 3.54 4.0 14.1 156 " 2.4YH 3.46 3.5 16.9 180 “ 2.7YR 3.44 3.4 18.1 * Unsalable ~112- “PPM-EM H Wrapped Sample Stored in Light Trial IV - Low Choice 20 Honth 01d Hereford Heifer Sample cut from rib 9 days after slaughter Cutting temperature - 65°F, Cooler temperature - 35°F Wrapped 3 minutes after cutting 30 foot Candles white fluorescent light No measureable rise in temperature due to light Standard 1YR 4.0/6.0 Time of Reading Units from after Cutting Hue Value chroma Standard 8 Hinutes 3.213 3.48 4.1 12.3 18 N 2.813 3.39 4.6 11.1 33 N 1.913 3.47 5.1 7.5 48 N 1.413 3.54 5.4 5.7 63 N 1.113 3.56 5.7 3.5 93 N 1.013 3.60 5.7 3.3 123 N 0.813 3.62 5.9 3.2 30 Hours 0.6YH 3.68 6.2 3.4 58 N 0.613 3.66 6.1 3.1 82 N 1.413 3.77 6.0 2.2 106 " 0.713 3.62 5.8 3.7 145 N 1.613 3.75 6.0 2.6 180 N 1.613 3.72 5.8 3.8 199 N 1.813 3.81 5.4 4.7 227 N 1.913 3.67 5.6 5.0 251 N 1.913 3.67 5.6 5.0 271 N 2.213 3.65 5.5 5.9 295 N 2.213 3.65 5.5 5.9 324 N 3.113 3.73 5.4 8.1 -113- HPPHNDIX H - continued Trial IV - continued Time of Reading Units from after Cutting_r Hue Value Chroma Standard 348 Hours 3.613 3.69 5.2 9.6 370 N 2.813 3.58 5.1 8.8 396 N 3.313 3.54 4.9 10.8 420 N 3.313 3.54 4.9 10.8 444 N 4.613 3.71 4.4 12.9* 468 N 4.913 3.41 4.2 15.6 490 N 5.413 3.51 3.7 16.4 * Unsalable -114- H”PHHDIX H - continued ed Sample Stored In Light Trial V - Low Choice 20 month Old Hereford Heifer Sample cut from rib 9 days after slaughter Cutting temperature - 65°F, Cooler teaperature - 35°F Wrapped 30 minutes after cutting 30 foot candles white fluorescent light N0 measureable rise in temperature due to light Standard 1YH 4.0/0.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 35 Minutes 1.4YH 3.94 5.2 3.8 45 N 0.413 3.86 5.3 4.0 60 N 0.313 3.90 5.5 3.6 75 N 0.113 3.92 5.7 3.6 90 N 0.113 3.92 5.7 3.6 105 N 0.113 3.92 5.7 3.6 135 N 9.73 3.96 5.8 3.6 150 N 9.73 3.96 5.8 3.6 30 Hours 9.78 3.96 6.0 3.1 58 N 9.53 4.10 5.8 4.7 82 N 9.53 4.10 5.8 4.7 106 N 9.73 4.07 5.6 4.7 180 N 0.213 4.02. 5.2 4.3 199 N 0.413 4.0 5.2 3.6 227 N 0.513 3.98 5.1 3.7 251 N 1.413 4.06 5.0 4.4 271 N 1.413 4.04 4.8 4.4 295 N 1.413 4.04 4.8 4.4 324 N 2.313 4.11 4.9 6.4 -115- HPPHHDIX H - continued Trial V - continued Time of Reading Units from after Cutting Hue Value Chroma Standard 348 Hours 2.113 3.98 4.6 6.2 370 N 2.313 3.95 4.4 7.1 390 “ 3.2YR 3.89 4.0 10.1 420 N 4.113 3.82 3.6 12.9* 444 N 5.213 3.76 3.3 14.8 468 " 6.813 3.70 3.0 17.8 490 N 7.113 3.68 2.9 18.2 * Unsalable -116- A1} :SIJDIX I Wrapped Sample Stored in Light - Immediate versus Delayed Wrapping Trial 30 - average Choice 2 Year Old Hereford Steer Sample Cut from rib 13 days after slaughter Cutting temperature - 07°F, Cooler temperature - 34°F Wrapped_3gminutes after cutting 215 foot candles wnite Iluorescent light nise in temperature at meat surface due to light 30F Standard 1Y3 4.0/0.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 5 Minutes 1.5YH 3.29 4.6 9.3 15 " 1.2YR 3.19 5.2 7.6 25 N 0.913 3.24 5.5 6.5 35 N 0.913 3.26 5.7 5.3 45 N 0.o13 3.28 5.8 5.7 55 " 0.513 3.31 6.0 5.4 65 N 0.513 3.31 6.0 5.4 80 " 0.2YR 3.38 6.2 6.2 95 N 0.213 3.38 6.2 6.2 110 " 0.1YR 3.40 6.3 6.8 125 N 10.03 3.42 6.4 7.4 25 Hours 0.0YR 3.66 6.1 3.1 54 N 1.013 3.60 5.7 3.3 76 " 1.0YR 3.58 5.7 3.3 98 " 1.113 3.67 5.1 4.7 122 N 1.513 3.63 4.9 6.7 150 " 3.113 3.67 4.6 9.9 174 N 3.413 3.65 4.5 10.6 213 N 4.313 3.57 4.1 13.5 HLPENDIK I - continued Trial 30 - continued Time of Reading Units from after Cutting; Hue value Chroma Standard 239 Hours 4.413 3.70 3.8 13.6* 295 “ 6.013 3.60 3.3 17.1 316 " 6.013 3.60 3.3 17.1 338 " 6.7YR 3.57 3.2 18.1 * Unsalable -118- HPPHNDIX I - continued Wrapped Sample Stored in.Light - Immediate versus Delayed Wrapping Trial 31 - Average Choice 2 Year Old Hereford Steer Sample cut from rib 13 days after slaughter Cutting temperature - 07°F, Cooler temperature - 34°F Hrapped 30 minutes after cutting 215 foot candles wnite fluorescent light Hise in temperature at meat surface due to light 30F Standard 1Y3 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 33 minutes 1.7YR 3.38 5.6 6.4 43 N 1.513 3.40 5.8 5.4 53 N 1.313 3.42 5.9 4.6 63 N 1.313 3.42 5.9 4.6 73 N 1.313 3.45 5.9 4.6 83 N 1.313 3.45 5.9 4.6 93 N 1.113 3.47 6.1 3.5 108 N 1.113 3.49 6.2 3.8 123 N 0.913 3.51 6.3 4.2 138 N 0.913 3.51 6.3 4.2 25 Hours 1.513 3.75 6.0 2.4 54 N 1.813 3.81 5.4 4.7 76 N 2.013 3.77 5.2 5.7 98 N 2.213 3.85 4.7 6.8 122 N 2.713 3.81 4.5 8.8 150 N 3.513 3.75 4.1 11.0 174 N 3.913 3.71 3.9 12.6 213 N 4.813 3.66 3.6 14.5 -119- APPENDIX I - continued Trial 31 - continued Time of Reading Units from after Cutting Hue Value Chroma Standard 239 Hours 5.0YR 3.78 3.4 14.4* 295 N 7.013 3.68 2.9 18.1 316 N 7.613 3.80 3.1 18.1 338 " 7.8YR 3.78 3.0 18.4 * Unsalable -120- Wrapped Sample Stored in Darkness - Immediate versus Delayed Wrapping APPENDIX J Trial I - Low Choice 18 Month Old Hereford Steer Sample cut from rib 3 weeks after slaughter Cutting temperature - 63°F, Cooler temperature - 34°F Wrapped 5 minutes after cutting, Standard 1Y3 4.0/0.0 Time of Reading Units from after Cutting Hue Value Chroma Stanggrd 10 Minutes 4.013 3.9 4.5 10.5 20 N 3.913 3.9 4.6 10.1 30 N 3.413 4.0 4.8 8.2 40 N 3.513 3.9 5.1 8.4 50 " 3.213 3-9 ' 5-3 7.4 60 N 3.213 3.9 5.3 7.4 70 N 3.013 3.9 5.4 6.7 90 N 2.913 3.9 5.5 6.3 120 N 2.513 4.0 5.7 4.3 150 N 2.513 4.0 5.8 4.1 31 Hours 2.3YR 4.0 5.8 3.6 56 N 1.613 3.9 5.8 2.6 72 N 1.613 3.9 g 5.8 2.6 80 N 1.113 4.1 5.8 1.5 96 N 1.113 4.1 5.8 1.5 120 N 0.913 4.1 5.9 1.1 144 N 1.113 4.1 5.8 1.5 168 N 0.813 3.9 5.5 2.5 222 N 1.813 3.8 4.8 6.3 241 N 1.813 3.8 4.8 6.3 265 N 2.313 3.7 4.9 7.6 289 N 2.713 3.6 4.7 9.5 Wrapped Sample Stored in Darkness - Immediate versus Delayed Wrapping APPENDIX J - continued Trial J - Low Choice 18 Month.01d Hereford Steer Sample cut from rib 3 weeks after slaughter Cutting temperature - 63°F, Cooler temperature - 34°F Wrapped130 minutes after cutting Standard 1Y3 4.0/5:0 Time of Reading Units from after Cutting Hue Value Chroma Standard 35 Minutes 2.9YR 4.2 5.5 6.9 45 N 2.713 4.2 5.7 5.0 55 N 2.413 4.2 5.8 5.0 65 N 2.413 4.2 5.8 5.0 75 N 2.413 4.2 5.8 5.0 85 N 2.413 4.2 5.8 5.0 95 N 1.913 4.1 5.7 3.6 145 N 1.513 4.2 6.0 2.4 26 Hours 0.813 4.1 6.0 1.1 50 N 1.113 4.1 5.8 1.3 79 N 0.813 4.1 5.9 1.4 87 N 1.313 4.0 5.6 1.9 115 N 1.513 4.2 6.0 2.4 139, N 1.513 4.2 6.0 2.4 163 N 1.513 4.2 6.0 2.4 187 N 1.713 4.0 5.4 3.3 229 N 1.613 3.8 4.9 5.7 259 N 1.913 3.8 4.7 6.8 283 N 2.213 3.8 4.5 7.9 308 N 2.513 3.8 4.5 8.4 * Unsalable APPENDIX K Wrapped Thawed Frozen Sample Stored in Darkness - Immediate versus Delayed Wrapping Trial Y - Low Choice 18 Month 01d Hereford Steer Sample cut from rib 8 weeks after slaughter - Frozen the last weeks Cutting temperature - 63°F, Cooler temperature - 34 F Wrapped 4 minutes after cutting ' Standard 1YR 4.076.0 Time of Reading Units from after Cutting Hue Value Chroma Standard 10 Minutes 4.3YR 4.56 3.5 15.7 20 N 3.913 4.60 3.7 14.8 30 N 3.113 4.48 4.3 11.7 40 N 3.013 4.38 4.5 10.5 55 N 2.813 4.41 4.7 9.7 70 N 3.013 4.52 4.9 10.2 85 N 2.913 4.53 5.0 9.8 100 N 2.713 4.55 5.1 9.8 115 N 2.513 4.56 5.2 9.1 130 N ' 2.513 4.49 5.4 8.0 29 Hours 2.6YR 4.38 5.6 7.2 50 N 3.313 4.41 5.0 10.0 67 N 4.613 4.51 4.4 14.1 91 N 4.813 4.49 4.4 14.5 115 N 4.413 4.41 4.3 13.3 139 N 4.813 4.38 4.2 14.2 163 N 4.913 4.46 3.9 15.4* 211 N 6.113 4.42 3.6 16.9 235 N 6.213 4.30 3.7 16.4 259 N 8.313 4.42 3.3 20.1 283 N 8.613 4.40 3.2 20.5 * Unsalable HFPSNDIX K - continued Wrapped Thawed Frozen Sample Stored in.Darkness - _ Immediate versus Delayed Wrapping Trial R - Low Choice 18 Month Old Hereford Steer Sample cut from rib 8 weeks after slaughter - Frozen the last 3 weeks Cutting temperature - 63°F, Cooler temperature - 32°F Wrapped 60 minutes after cutting Standard lYR 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Standarg__ 65 Minutes 3.313 3.86 5.7 6.7 75 N 3.313 3.88 5.8 6.5 85 N 3.313 3.88 5.8 6.5 95 N 3.313 3.88 5.8 6.5 110 N 3.013 3.92 5.9 5.6 125 N 3.013 3.92 5.9 5.6 250 N 3.013 3.92 5.9 5.6 28 Hours 2.913 4.02 5.5 5.7 52 N 3.513 4.05 5.0 8.6 76 N 3.413 4.07 5.0 8.4 100 N 3.913 4.02 4.7 9.4 124 N 4.313 3.98 4.5 10.4 148 N 4.613 4.06 4.3 11.9* 172 N 5.513 4.13 4.2 13.6 196 N 6.013 4.02 4.3 13.7 220 N 6.713 3.98 4.1 15.0 244‘ N 6.713 4.10 3.9 15.8 2o8 N 6.013 3.99 3.7 14.3 292 N 7.013 3.95 3.5 15.9 316 N 8.013 4.03 3.5 17.3 340 N 7.513 4.05 3.2 17.3 * Unsalable APPENDIX K - continued Wrapped Thawed Frozen Sample Stored in.Darkness - Immediate versus Delayed Wrapping Trial W - Low Choice 18 Month Old Hereford Steer Sample cut from rib 8 weeks after slaughter - Frozen the last 3 weeks Cutting temperature — 63°F, Cooler temperature - 34°F Wrapped 30 minutes after cutting_ Standard lYR 4.0/6.0 Time of Reading Units from after Cutting Hue Value Chroma Stdndard 40 Minutes 3.5YR 3.6 4.4 11.6 50 N 3.313 3.7 4.6 10.2 60 N 3.113 3.7 4.6 9.9 70 N 2.813 3.7 4.7 8.9 85 N 2.713 3.7 4.8 8.7 95 N 3.113 3.7 5.4 8.1 110 N 3.013 3.8 5.6 6.9 125 N 3.013 3.8 5.6 6.9 140 " 2.613 3.8 5.7 5.7 155 N 2.613 3.8 5.7 5.7 28 Hours 2.613 3.8 5.7 5.7 50 N 2.513 3.6 5.4 7.4 76 N 3.513 3.8 4.8 9.6 100 N 4.113 3.8 4.6 11.1 124 N 4.013 3.6 4.3 12.7 148 N 4.413 3.6 4.2 13.5 172 N 4.613 3.6 4.0 14.2* 196 N 5.113 3.8 3.3 14.7 220 N 7.413 3.68 3.3 18.3 244 N 8.413 3.64 3.1 20.3 268 N 9.213 3.60 2.9 21.2 292 N 9.713 3.57 . 2.8 21.7 * Unsalable I‘ .nv " x». . 1;" ' .- "‘i m 1510 1961 ,uf ’5/21 6/ “W