4v : i.; L”: STORAGE G? WHATHAN A?PLES 3N camamtm ATMOSPHERES ANS} Fem CRATE LENERS Thai: for tho Degree of M. 3. MSCHIGAN STA?§ UNIVERS‘IT‘I‘" ‘Waiter Eimer Buflinger €955 'THE’Q‘Q mm11111111111 mm m 3 129 310561 9617 STORAGE OF JONATHAN APPLES IN CONTROLLED ATMOSPHERES AND FILM CRATE LINERS By Walter Elmer Ballinger AN ABSTRACT Submitted to the School of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Horticulture 1955 I I /\ I L" '1 Approved by q:' 1”“‘kflég / 1' r5=°gageqtf I f I Walter Elmer Ballinger 1 Jonathan, a leading variety of apples grown in Michigan, is usually held for a maximum period of four months in regular refrigerated storage. Since a temperature of 32°F favors the development of soft scald, the fruit is generally stored at 36°F. At the latter temperature, however, Jonathan spot frequently becomes serious and the apples have to be marketed accordingly. Controlled atmospheres in conjunction with storage temperatures of 32, 36, and h0°, therefore, were tested as a means of preserving quality and lengthening the storage life of this variety. Apples grown in the experimental orchard at East Lansing were stored October 7, l95h in normal air and in at- mospheres adjusted to carbon dioxide and oxygen percentages, respectively, of 0.5 and 3, 2.5 and 3, S and 3, and 7 and 13. The fruit was examined for changes in external appearance, ground color, firmness, soluble solids, internal disorders, taste, texture, acidity and pH on December 15, 195h, and March 20 and May 2, 1955. Controlled atmospheres were beneficial in maintaining good quality and prolonging storage life. Best storage was attained atjny in 5% carbon dioxide and 3% oxygen. Other atmospheres that yielded promising results at 32° were 2.5% carbon dioxide with 3% oxygen and 7% carbon dioxide with 13% oxygen. The best atmosphere for storage at 36° was 5% carbon Walter Elmer Ballinger 2 dioxide - 3% oxygen. Storage at h0°, regardless of atmos- pheric condition, was unsatisfactory. Carbon dioxide injury was more prevalent at hO°F than at lower storage temperatures. Carbon dioxide levels of 0.5, 2.5, and 5% with 3% oxygen were not injurious at 32°. Slight injury developed in 7% carbon dioxide - 13% oxygen at 32°. Apples at 36° were free of injury in 0.5 and 2.5% carbon dioxide with 3% oxygen. Jonathan spot was effectively controlled in atmospheres of 2.5 and higher per- centages of carbon dioxide at all temperatures. The inci- dence of soft scald was extensive at 32°, slight at 36°, and nil at h0°. Over 50% of the apples stored in normal air‘at 32° had soft scald by March 20, whereas, those in controlled atmospheres at this temperature remained practically free of soft scald for the entire storage period. Modified atmospheres, in which the carbon dioxide and oxygen levels were not controlled, were tested with film crate liners. One-bushel quantities of apples were stored at the above temperatures in sealed 250 and 150 gauge poly- ethylene, sealed 100 gauge Saran 517, and non-sealed 250 gauge polyethylene. Same of the sealed film crate liners were opened January 6 when the fruit became damaged; the I rest were opened and examined March 20. Sealed liners were found to be undesirable for the storage of Jonathan at all three temperatures. The enclosed fruit was damaged by the development of adverse levels of Walter Elmer Ballinger 3 carbon dioxide and oxygen. Injurious levels of carbon dioxide and oxygen did not develop within the folded liners; however, Jonathan spot and soft scald were not controlled. Additional experimentation to verify these findings under variable seasonal conditions is desirable before defi- nite recommendations are made for the storage of Michigan- grown Jonathan apples in controlled atmospheres. ACKN OULEDGMEN T S The author extends his sincere thanks and gratitude to Dr. D. H. Dewey for his constant supervision, encouragement and guidance throughout this study. The writer appreciates the constructive suggestions given by Dr. L. W. Mericle upon reviewing the manuscript. ' Appreciation is due Dr. C. L. Bedford for his interest and frequent assistance during the course of the study. The author is also indebted to the members of the Botany and Horticulture Departments who served as members of the comittee e STORAGE OF JONATHAN APPLES IN CONTROLLED ATMOSPHERES AND FILM CRATE LINERS BY Walter Elmer Ballinger A THESIS Submitted to the School of Agriculture of Michigan State University of Agriculture and Applied Science . in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Horticulture 1955 THESIS TABLE OF CONTENTS Page IN TRODUC TI ON 0 O O O O O O 0 O O 0 O O O O O O O O 1 4:- IflEVIEW OF LITERATURE . . . . . . . . . . O O O O H 0 ETHOD S O O O O O O O O O O O O O O O O Fruit 0 O O O O O 0 O O O O O O 19 Controlled Atmosphere Chambers . . . . . . . . . . 19 FIlm.Crate Liners . . . . . . . . . . . . . . 22 Observations and fiDeterminations . . . . . . . . . . 23 RESULTS 0 O O O O O O O O O O O O O 0 O O O O O O O 27 contrOlled Atmospheres e e e e e e e e e e e e e e 27 Carbon Dioxide Injury . . . . . . . . . . . . . 27 Jenathan Spot . . . . . . . . . . . . . . . . . 30 sort scald e O o e e e e e e e O O o e e O 33 Surface MOld and Decay e e e e e e e e e e e e e 3“. Flavor and TOXture e e e e e e e e e e e e e e e 3 Internal Breakdown . . . . . . . . . . . . . . . 3 Flesh Firmness . . . . . . . . . . . . . . . . . 36 Ground 0010:. C O I O O O O O O O O O O O O O O ’40 SOluble SOlids . O O O O O O O O O O O O O O O 0 1+0 ACidity O C O C O O O O O C O O O O O O O O C C “.0 Film Crate Liners 0 e e e e e e e e e e e e e o e 0 “)4. Carbon Dioxide and Oxygen Concentrations . . . . uh Condition of Fruit . . . . . . . . . . . . . . 52 DISCUSSION 63 sUWARYANDCONCLUSIONS............... 71 LITERATURECITED..................75 ‘ ”6155'? LIST OF TABLES TABLE Page I. Carbon dioxide injury of Jonathan apples after storage to March 20 at uO°F in controlled atmos phere a O 0 C . O O C O O O 0 O O O O O O 29 II. Percentage of apples stored in controlled atmospheres developing Jonathan spot . . . . . 32 1111. Percentage of Jonathan apples stored in controlled atmospheres with internal breakdown 37 IV. Pressure readings, in pounds, of Jonathan apples stored in controlled atmospheres . . . . . . . 39 V. Ground color ratings of Jonathan apples stored in controlled atmospheres . . . . . . . . . . Al VI. Percent soluble solids of juice of Jonathan apples stored in controlled atmospheres . . . u2 TIII. Acidity of Jonathan apples stored in controlled atmospheres.................1i} VIII. Atmospheres deve10ped at 1+0°F in film crate liners eeeeeeeeeeeeeeeeeoe LLS SIX. Atmospheres developed at 36°F in film crate liners eeeeeeeeeeeeeeeeeee 1+6 .X. Atmospheres develOped at 32°F in film crate liners . . . . C O C C C C O C . C . . C C . “7 3:1. Observations of Jonathan apples stored in sealed Saran crate liners . . . . . . . . . . 5h I[31121. Observations of Jonathan apples stored in sealed 250 gauge polyethylene crate liners . . 55 JXDEJEI. Observations of Jonathan apples stored in sealed 150 gauge polyethylene crate liners . . . . . 56 IJKEEV. Observations of Jonathan apples stored in folded 250 gauge polyethylene crate liners . . . . . 57 3(V. Ground color and flesh firmness of Jonathan apples stored at three temperatures in film crate liners to March 20, 1955 . . . . . . . 6O TABLE XVI. Soluble solids, pH and titratable acidity of Jonathan apples stored at three temperatures in film crate liners to March 20, 1955 . . . . . 61 LIST OF FIGURES FIGURE Page 1. Jonathan apples in sealed film crate liners con- LL. 5;. '7. E3. 10, 11- nected by means of a plastic tube to the orsat gas analyzer for measurement of Carbon dioxide and oxygen surrounding the fruit. . . . . . . . A metal chamber used for the controlled atmosphere storage of two bushels of apples . Flesh injury of Jonathan caused by adverse concentrations of carbon dioxide and oxygen in the storage atmosphere.. . . . . . . . . . . Surface injury assOciated with the damage showninFigur63eee............ Carbon dioxide injury at the core of Jonathan . Soft scald injury of Jonathan apples. . . . . . Jonathan apples with Jonathan spot . . . . . . The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 150 gauge polyethylene crate liners during storage at temperatures of 32, 36 and u0°F. . . The most severe conditions of carbon dioxide accumulation or oxygen depletion within folded 250 gauge polyethylene crate liners during ' storage at temperatures of 32, 36 and uO°F. . . The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 250 gauge polyethylene crate liners during' ' ’ storage at temperatures of 32, 36 and u0°F. . . The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 100 gauge Saran 517 crate liners during storage at temperatures of 32, 36 and'hO°F . . . . . . 21 21 28 28 28 31 31 h8 1&9 So 51 " INTRODUCTION Jonathan is one of the most important varieties of apples grown in Michigan. According to a 1950 survey (Davis, 31; 51, 1950), 28% of the producing trees in Michi- gan were Jonathan, with the other leading varieties Deli- cious, McIntosh and Northern Spy accounting for 11+, 12, and 10% respectively of the bearing trees. 0f the non-bearing trees in 1950, 29% were.Jonathan, which was 8% greater than the next leading varieties of Delicious and McIntosh. Ac- cording to a recent census (U.S.D.A., 1951+), Michigan led the United States in the production of Jonathan with 1, 180,000 bushels, as compared to 1,090,000 bushels in Washington. The Jonathan is a popular all-purpose apple. In Mid- Western markets it is one of the most useful apples for C1assert and culinary purposes as well as for processing (Flagge, 19112). The apples are well-suited for prepackaging in consumer-size transparent bags. Consequently, the variety has a high market value and could be marketed through the ye er (Plagge, l9LL2). «Jonathan apples are not presently available throughout the year since they have a storage life of about three rughths in ordinary cold storage at approximately 36°F. Storage at 32°, as recommended for many varieties, may extend the storage life to the end of January (Phillips and Poapst, 1952), but they are then susceptible to soft scald, a serious physiological disorder. Although soft scald develops less readily at storage temperatures of 35 or 36°, another disorder, Jonathan spot, may cause serious losses. Jonathan spot becomes more prevalent as the storage season progresses so that the apples must be frequently inspected and moved into market channels before excessive damage occurs. There- fore, at either of these temperature levels in ordinary cold storage, the storage life of Jonathan apples is restricted. The storage life of other varieties in the Northeastern States and in England has been greatly extended by utilizing cold storages in which the atmosphere of the storage chamber The normal oxygen content is decreased and the It is of is modified. concentration of the carbon dioxide is increased. Particular value for McIntosh because its storage life at 38°F is equal to or longer than in ordinary storage at 32°. At the latter temperature, brown core is a serious threat, whereas it usually does not develop at the higher temperature. Similarly, it would seem that the combination of temper- attires of 36°F or higher and modified atmospheres would prove Valuable for Jonathan. However, the tolerance of Jonathan to different levels of carbon dioxide has not been clearly ea'Itablished. For example, Smock (1914.9) reported that Jona- than apples grown in New York were severely damaged by carbon 6‘1 oxide in controlled atmospheres. Plagge (19h2), on the other hand, found that this variety in Iowa could be favorably stored in a high level of carbon dioxide without evidence of injury. There is no available information on the response of this variety grown in Michigan to various levels of carbon dioxide in storage or to its suitability to controlled or modified atmospheres. The purpose of this experiment, therefore, was to study the response of the Michigan-grown Jonathan apples to various concentrations of carbon dioxide at several temperatures and to evaluate modified atmospheres as a means of maintaining high quality in this variety during the cold storage period. REVIEW OF LITERATURE Controlled atmosphere storage has often been termed gas storage, modified air storage and modified atmosphere storagee The term gas storage is mdsleading in that it in- correctly creates an impression that a harmful or poisonous gas is used for the storage of apples (Dewey, gt 31, 195k). Modified atmosphere storage is correct in a few instances such as in sealed crate liners where the gas levels are changes, but not actually controlled. However, North.Amer- ican investigators have generally used controlled atmosphere as the most accurate and desirable term.(Fisher and Porritt, 1951). -The values of controlled atmosphere storage for prolong- ing the storage life of apples have been known for some time. High quality can be maintained for longer periods than in , low temperature storage alone and improved firmness and flavor, and better retention of ground color have been reported by numerous investigators. Physiological disorders such as core- flush or brown core, caused by low temperatures, can be avoided and losses due to wilting or shriveling can be minimized (Phil- lips and Poapst, 1952; Fisher, 1939). The values of controlled atmospheres extend beyond the storage period since, upon re- moval from storage, the'apples frequently have a longer shelf- life than fruit from regular storage. This residual effect is especially marked for the variety McIntosh (Smock and Neubert, 1950). The principle of controlled atmosphere storage centers around the process of respiration (Dewey, et al, 195h; Fisher and Porritt, 1951; Smock and Van Doren, 19ul). A11 fruit, before and after harvest, carries on respiration in m which the sugars of the fruit are utilized in the presence { of oxygen. The usual and products of this oxidation are carbon dioxide, water and heat. The amount of oxygen used is about the same as that of the carbon dioxide produced A} (Smock and Neubert, 1950). The greater the rate of respira- -' tion, the more rapidly the apples deteriorate. The respiratory rate can be controlled by several means. One is to lower the temperature. This is the fundamental principle of cold storage. Another means is to reduce the quantity of oxygen surrounding the fruit in storage so that it is limiting for the respiratory reaction. A third means is to increase the concentration of carbon dioxide so that the chemical reactions in respiration are slowed by the accumu- lation of one of the end products (Brooks, 1939). All three are employed in the controlled or modified atmosphere storage. Controlled atmosphere is not new. According to West (1951), fruit growers in England around 1919 realized a need for an improved method to keep their late varieties of apples. Their apples did not keep favorably under refriger- ated storage, although apples and pears from America held under cold storage and shipped to England were satisfactory. Early experiments showed many home-grown varieties to be in- tolerable to the low temperatures in general use in America at that time, due to low temperature breakdown. The optimum temperature for storage of the leading varieties of English apples in air was 37 to hO°F, except that they ripened too quickly at that temperature. Control of the storage atmos- phere for the Bromley's Seedling variety at 9% carbon dioxide, 12% oxygen, and a temperature of 38° was best (West, 1951)._ Kidd and.Uest conducted extensive experiments in.Eng- land with many varieties of apples. In 1929, controlled atmosphere storage was initially used as a supplement to refrigerated storage in England (West, 1951) and it became of commercial importance within the next ten years (Loudon and Zuroske, 1953). I In the United States, commercial controlled atmosphere storages for apples have existed for approximately 15 years (London and Zuroske, 1953). The work in this country has been directed toward improving or prolonging the keeping of apple varieties that are subject to certain cold storage disorders (Plagge, 19h2). It is estimated that about 90% of the controlled at- mosphere storages in the United States are for the McIntosh variety. The temperature and carbon dioxide recommendations established thus far for various varieties are: McIntosh, 38°F, 5%; Red Delicious, 32°, 2%; Golden Delicious, 32°. 2%; 44 ”4 ‘ii in: '1 Ti .14. ..I.I .I u.‘ l" Romes, 32°, 10%; Northern Spy, 38°, 10% (Dewey, et a1, 195A). The proper level of oxygen for these is 3%, but because of the variable requirements of temperature and carbon dioxide, mpst varieties must be stored separately. Experiments with Jonathan have shown that Jonathan spot can be controlled by this type of storage, but further ex- perimentation is required to discover the Optimum.conditions. Smock and Van Doren (l9hl) and Smock (l9h9) at Cornell feund that Jonathan did.not respond well to a controlled atmosphere of 5% carbon dioxide and 2% oxygen at hO°F. All apples over two and one-half inches in diameter had severe flesh browning and many were soft due to a complete browning and breakdown of the flesh. They reported that Jonathan seems to be very susceptible to carbon dioxide even at relatively high storage temperatures. However, there was no Jonathan spot development in storage or when the fruit was held at room temperature for two weeks after removal.from.storage. Because of these re— sults, Smock and Van Doren advised against commercial controlled atmosphere storage of Jonathan until.further trials with very low levels of carbon dioxide and oxygen could be made. In 19h2, Plagge reported that storing Jonathan at 31-32° and 35-36°F in carbon dioxide concentrations of approximately 7, 9, and 11% increased the marketable storage period 3 to h months over that of air-stored fruit; concentrations of 3 to h% of carbon dioxide were not quite as effective, but never- theless, lengthened the storage period by 2 to 3 months. A.temperature of 32° with 3 to h l/ % carbon dioxide yielded fruit of the best flavor, but best all-around keeping quali- ties were obtained at 7%; the apples were free from brown heart and developed characteristic Jonathan flavor. Some brown core and soggy breakdown were found at 9 and 11%, the two highest carbon dioxide concentrations tested. Full, :1. rich, Jonathan flavor was always lacking at these two con- centrations, even after they were ripened at room tempera- ture. Plagge concluded that controlled atmosphere maintained quality, prolonged the market season, and controlled Jonathan spot, but did not control soggy breakdown of Jonathan at 32°. Plagge and Fisher (1942) studied the pectic changes in Jonathan apples as a measure of ripening under differential carbon dioxide treatments. They found that the concentra- tion of carbon dioxide was directly proportional to its in- hibiting effect upon the hydrolysis of protopectin to soluble pectin, that is, the greater the concentration of carbon dioxide, the more slowly the fruit ripened in storage. A comparison of samples held at 32° and 36°F revealed a slightly further advanced condition of protopectin hydrolysis with the higher temperature. Although ripening, as judged by flavor and freedom from brown heart, was best retarded at the 9 and 11% levels, 7% carbon dioxide at both 31-32° and 35-36° seemed best for general storage. Workers in other countries have also reported experi- mentation with controlled atmosphere storage. Van Hiele (1951) reported that 150 tons of Jonathan apples were com- mercially stored in refrigerated controlled atmosphere stor- ages in the Netherlands in 1950-1951; 7% carbon dioxide and 13% oxygen were successfully utilized. Jonathan, the leading variety in Victoria, Australia, has been stored under con- trolled atmospheres with considerable success, according to Vickery, et al (1951). Soft scald was minimized by storing the fruit for the fhPst h weeks at 36°F, the next h weeks at 3u°, and thereafter at 32°. Jonathan spot was virtually controlled by storage in 5% carbon dioxide and 16% oxygen; in addition, bitter pit and decay were consistently reduced. Storage under the above conditions increased the storage life of Jonathans to 6 months, or 2 months longer than in regular refrigerated storage and produced a residual effect in that the stored fruit retained its superior quality after removal from storage and had a longer post-storage life. Vickery, et al suggest that retardation of softening and flavor losses are mainly effects of carbon dioxide. E. G. Hall (1955) re- ported that 5% carbon dioxide and 16% oxygen have given very satisfactory results with the Australian-grown Jonathan. In Denmark, Rasmussen (1951) reported complete control of Jonathan spot under controlled atmosphere conditions of 8 to 10% carbon dioxide and 11 to 13% oxygen. Controlled atmospheres are also under test in Canada. Phillips and Poapst (1952) included Jonathan in a list of varieties which experimentation thus far has shown no r44—7;" 7“ ‘ . 2‘1-h-r—I- ache-v I s“ '-1 I'M c... ‘4- "I 'rw '0" u..1 u“ q 10 advantage of controlled atmosphere storage over ordinary storage . Since then, D. V. Fisher (195A) of the Canadian Department of Agriculture Experiment Station, Summerland, EL 0., found that concentrations of h% carbon dioxide and 16% oxygen gave complete Jonathan spot control, although for Inst quality preservation concentrations of 7% carbon dioxide and 13% oxygen were preferred. Plastic-film crate liners are sometimes used to help lengthen the storage life of apples. These crate or box liners have been used several years primarily for the pur- pose of preventing excessive water losses and the resultant shrivel, especially with the variety Golden Delicious. Har- denburg (195A) stored this variety in various types of sealed and'unsealed crate liners at a storage temperature of 31°F and 85-90% relative humidity. Definite gas-storage effects were achieved with 150 gauge Polyethylene bag liners. The rate of ripening, as determined by ground color changes,was decreased, the apples in such sealed film-lined boxes were three to four pounds firmer than those in the non-sealed éontainers, and decay was decreased. Oxygen levels in the sealed liners averaged 2.h to 2.8 percent and dropped as law as 0.9 percent. Carbon dioxide concentrations averaged 5~5 to 5.9 percent. Hardenburg concluded that the dangers of the gas-storage effect outweigh the advantages and recomp mended the use of non-sealed liners. 11 In their work with Golden Delicious apples, Gerhardt and Schomer (195h) found that sealed liners had no effect on the soluble pectin, but respiration was retarded and flavor was maintained. High moisture-proof liners such as 300 MSAT and u50 MSAT cellophane, and Pliofilms 120 PM and 120 P6 should not be used since they are-too resistant to the movement of carbon dioxide and oxygen gases. Polyethylene 150 and Pliofilms 80 FMl and 80H? were the most satisfactory for sealed liners. Gerhardt and Schomer were of the opinion that benefits from sealed liners have not been proven. Plagge and Maney (19hl) lined boxes and baskets of Jhnathan with pliofilm, inserted a copper tube to the centers of the boxes and sealed them. The apples were held until the latter part of March at 35-36°F. The carbon dioxide concentration varied from.h.6 to 6%. Although the fruit was overmature and therefore susceptible to Jonathan spot, the sealed fruit had only 13 percent compared to 83.5 percent spot on the check lots of fruit at the end of the storage period. Disorders such as mealy-breakdown and internal breakdown, iflaich are associated with senility or old age of the fruit, develop more slowly in controlled atmosphere storage than in ordinary storage (Smock and Neubert, 1950).. There are 8‘ev'eral disorders of Jonathan that are not particularly aSsociated with senility, but are affected by storage con- ditions. One of these is Jonathan spot (Plagge and Haney. 12 192k). It has been known in this country for at least half a century, since it was recognized in Virginia and West Virginia in 1911 (Healer and Whetzel, 1920). The symptoms leave been reported by numerous authors (Smock and Neubert, 21950; Brooks, 21 £1, 1920; Healer and Whetzel, 1920; wright, 21953; Plagge and Nancy, l92h; Rose, 9; g}, 1951). The die- ¢1rder is manifested by dark-colored superficial spots which *vary in size from minute dots to a quarter of an inch or more in diameter on the surface of the fruit. The spots are gen- orally circular in shape and centered at lenticels, but they sometimes merge, forming irregularly shaped patches (Fisher land Porritt, 1951). Although Jonathan spot sometimes occurs oe caduceus use moweao><* III III ameOHwofl 0000+ OOH :NOOHOOMH 00.0%..3." fiODdfi0< 00.0...33 8.0... .3 00. 0.3 00.0%...." 00.0.4.3 mmA. .3 0.3 0.5 00.0mm 3 0....0H0 S 3.0% 3 00.3%.3 30.0%.3 00.3..”H S 0..m 0.m 3.0“: 3 2.0%. 3 3.0...» 3 00.0...a.3 3.03.3 00.3... .3 0.m m.0 mm 2.” .6- 30.3.3.3 00.0.1.3 soéufifi 00.30.43 e323 3.0% 3 00.0.». 3 3.30 3 30.3... 3 2.0... 3 003.... 3 0 3 0.. 00.0H0.3 3.0..” .3 3.0%.3 2.0“ .3 00.1.0.3 3.3.0.3 0.m 0.m 3.0.3.3 00.0%.3 3.0.1.3 3.0%.3 30.0%.3 SAHTS 0.m ms... 3.000 3 8.3m 3 mash.» 3 3.0..”m m. 8.0...b 3 3.0.... m. 0 m m 0 3 H H .3... mi. .2... 3.0. 3.3. 00.0..3 33...... 0 3 0 a u-.. 2... «0.0% “a 8.3“.” 3 5.0“. 3 00.3. 3 0 m 0.m .II' -0- O H II 0 .H OMH O O 0 0.0.0. . no.0. m 00.3mm 20.3....0. 3 0 m m m 2... .3- I3 3 I~.3 ITNA 10.3 0.m m.0 0: 05.0. no.0. no.0. 30.0. a “$00 . mm a. .a 3-0.. 0. . -0 a. we a. E: 3 .8004 m as: 23m 3 .303 0m no.3: uhmmmwa moped 3 .80 W0 M00 m. .. genes: omqqomazoe 3 Queen magma. 255423. .8 $350.. 2.3 $0285.... $035.. 3:03am. .«0 20E >H Hmmn mmmmmmmozfid NH mnm<9 87 605:0008 pen I_MV .. a- a- u- «.5 5.0 0.0 0.5 005 u- a- u- u- 0.5 0.0 0.0 0.5 ««5 in is an I: 0.0 5.5 5.0 5.5 m0 0.05 0.05 0V. 000 0.0 0.5 0.0 0.5 55 5.0 0.05 0.5 0.0« 5.5 0.5 5.0 0.0 mm 0.55 «.55 0.0 0.0« 0.0 0.0 «.0 0.0 00 0.55 0.0 5.0 0.«5 0.0 5.0 5.5 0.0 05 0050.0 00500 0050.0 .ocomummmummmnmmd «.0« 0.0 0.0« 0.0 a- a- 0.5 0.0 005 0.05 0.0 0.05 5.0 .-s -u «.5 0.0 ««5 0.0« 0.0 m.0« «.0 a- u- 0.5 0.05 00 «.0« 0.0 .0« 0.0 0.0 0.05 0.0 «.«5 55 «.0« 0.0 0.0« 0.0 «.0 0.05 0.0 0.«5 mm 0.05 «.0 5.05 0.0 0.0 0.05 0.0 0.05 mm 0.0« 0.0 0.0« 0.5 5.5. 0.05 0.0 0.05 05 .00 .50 500 550 .00 5a. 500 500 «0 «00 «0 «00 . «0 «00 «0 «00 N pod a pod N uoq A non omdnoum 0.0500 qccmmummmwmmMImww 005000 .ocmmwmmmwwmmnmww 00 0500 000255 05<00 :550 25 .m.«m 54 000050000 00000500254 5.05045 Percent Carbon Dioxide And Oxygen is 32°F F 1 36°F I fit 1 db 1 Days an ......... FIG. 8. The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 150 gauge polyethylene crate liners durin storage at temperatures of 32, 36, and 0°F. ‘ . * - . '- .'~I€‘1k"1 d. -i Percent Carbon Dioxide And Oxygen 1L9 30 32°F 200 |"di III-dboeeeeeseeeeeeepeeeeeeeeesees-neeelse-Ieeeeqpeeeeeeeeeeecansenes-Illnesses-IIOI"""9'01 - A A A A A A A A A A A L - A V V v v f v V v v ' V V 0 20"\\\F w—f 4? 36°F ' 1D ‘OICIICIIIIIIII. I. .IIIIIIIIIICIOUIIOIIOI .-II.I.-IIIOIICIUCCUIIIIIIIICICU .CCCQCIUUICIICICOI. O * A, 7 fix ' o O _ A v T V V ‘ - L f r v V ' 0mg" 5 : 40°F A A A A A - A A A A 0 FIG. 9. 5'0 I60 ' I50 Days 0% The most severe conditions of carbon dioxide accumulation or oxygen depletion within folded 250 gauge polyethylene crate liners during storage at temperatures of 32, 36, and hO°F. Percent Carbon Dioxide And Oxygen 50 30 32°F 0 20i 1 '00 eeeeeeeeeeeeeee ee ...... eel eeeeeeeeee nee-0'" ‘P o ; :‘ng : j: a = t‘ c A: : : : 30 36°F 1 ""1 I _ ‘ £0. 5 - ‘ ‘ - - 40°F e ueee llllll eeeeeeeenehe-e ..... ee ----- t v : ; A r ; A i ._.___ A; A, 50 I00 . ISO D a y s €02 .e ....... 02 — P160100 The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 250 gauge polyethylene crate liners during storage at temperatures of 32, 36, and 00°F. Percent Carbon Dioxide And Oxygen 51 32°F ‘fl’A' “A: imfij 'i I“ 36°F 1 1D 1 F13. lle ISO Days C% ......... The most severe conditions of carbon dioxide accumulation or oxygen depletion within sealed 100 gauge Saran 517 crate liners during storage at temperatures of 32, 36, and 00°F. 52 32 or 36°. with the small increases in carbon dioxide, there were equivalent decreases in oxygen. The carbon dioxide con- centrations in the sealed polethylene films (FIG. Stand 10) reached.maximum levels shortly after placement in storage and then decreased slightly during the rest of the storage period. Generally, the concentrations of carbon dioxide were greater at the higher temperatures than at the lower temperatures. An exception was 150 gauge polyethylene wherein the levels were similar throughout the test period at 32 and 26°. The 250 gauge polyethylene allowed a greater accumulation of car- bon dioxide than the thinner 150 gauge material. Oxygen levels below 1% occurred within the sealed polyethylene, and the total percentages of carbon dioxide and oxygen were less than 21% in all instances. Carbon dioxide continually accumulated in the sealed Saran at 32 and 36°F so that concentrations in excess of 30% were obtained in one to two months of storage. The oxygen was quickly depleted and could not be measured with the orsat apparatus as the carbon dioxide levels increased. The behavior of Saran at h0° was different than at the two lower tempera- tures; it reached a maximum level of about 20% and then de- creased to nearly 13%. In this material, the oxygen was de- creased no lower than 2.0%. Condition of Fruit Visible injury was observed after two and a half months on fruit stored in all lots of sealed Saran at 32 and 36°F, 53 and in single lots of sealed 250 polyethylene at 32 and 36°. These liners were opened at this time, January 6, for further examination of the fruit. The others were not opened until March 20, after approximately 5 months of storage. The measurements and evaluations of fruit condition immediately upon removal from storage and after holding samples of 20 apples at room.temperature for 10 days are summarized in Tables II to XIV. Storage in liners was not satisfactory at 32°F. The fruit was susceptible to carbon dioxide injury in sealed liners and to soft scald in folded liners or in the sealed liners that accumulated relatively small amounts of carbon dioxide. Fruit of satisfactory flavor and texture was found in one lot of sealed Saran. This lot was one of the two stored at 00°: however it was of poor general condition due to Jonathan spot and carbon dioxide injury. A single lot of fruit in 150 gauge~polethylene was free of injuries and judged to be of fair condition for marketing (see Table XIII). As shown in Table XIV, all apples stored in folded 250 gauge polethylene at 36°F were free of defects except for a minor amount of Jonathan spot in one lot. The texture and flavor were of fair acceptability for marketing. Those at h0° had 13 to 24 percent Jonathan spot and were mealy and lacking in flavor. .. n. 0. \ [0.05. IWEF. - . 4 000005000 u.mV in. Amaswca N.ma H.0H twwoo oao>omv ow wyd mma N 5 552 0000 000.0 «m o o N 0 m 00 5500505 «00 . . 000 0000 .0 0 05 « 05 Ho enamoomv on . on mmd H 0005055 0000 0000 0« 0 0 0.« 0.0« Amasnna OHHon “Vo+o ewm: N N Noo go>omv iooad mom 0 0 mo 00.0.." m 552 0000 550552 0 0m 0000 OH 00000 mw_+0 N “manna“ £300 dado: op +.m: 00 0000000 -00000 -0050 00 0 0 «.0 00 «0 5 552 0000 55000000 0.05 0050 . 0008 752:0: 80 05505.5 . . 2.305 00 60.50 00%. up»: «.0 m 00 0000000. 0000 55000550 55 0 0 0.55 0.0 H02 on 0005234. aSom «m N “hadnna oaaofl iw.o +.:m oo oao>omv nooad on on 552 0000 .000050 00 0 0 5.0 0.«5 «0 5 .1 va 500 500 mu. mmv 50500 50 0 has aH poem canon o oo 0O5awm on: damaSee hpaaanapoxaaz 0559503 aoaaam moo asapaSOH auom nonenaaoap< :5 emcam owaaoum non owaaoum meZHA afidmo z00 m.d 0.0 00 0000 0000 05500 om 0 0 . 00 00 005 5 552 -005< 0.0 0.05 05¢me 555mm 0mm?» V MWN $.05 no 0.530.00m80.“ 5 M0 . 0 5000 0 05550000000: 0000005 000050 00000000 0000 0000000000 05 00000 0000000 0000000 050 0 00 005050000 mmfizHA MB4MU mzmAMmBMfiuom MGDmMmmO HHN mflmwm mmwca wws m.~ 0.0 on oscv as «an oaaon :m o 0 on cu mma N HHz . madam -ooa< m.o :.oa .mmmv om “whduNOp 0H Hound ca manna“ mmmcaamos m.n How 00 0» ozcv unmflam noom om H o on on mma a HHz madam «.0 o.HH N.H Hoe -on- ofiao: on on Hfiz coca -oo~< m o : m.o 0.0 mma m Auo>mam ahac new endpxou 0H umpum .hhdnau moo mwmcaaaoa , H.H mom NM .vamom pmomv unmaan oaaon m H HH on 0» mma H adz madam nooaq m.o o.» «fiv oww hawmwa mem canon mRv may Amman. Amov muwaanauoxpaz ousuuoa ao>aam moo Gdnuchh puom o oo weapom ohsuwuoasoa pasnm mo :oauwcnoo monogamoau< Ca owndm omanoum pod owwn0pm mmMZHA m94mo NZMANMBMMuom mwb¢u omH QMQ¢MW zH QMMOBm mmqmm< zmmmmo HHHN mnmaHm nwoo canawGOh whom monogamQEp4 :H omcwm owaOpm omanoam pHsum HomwmpHunoo mmflZHq memmwmo >HN mnm<fi 58 The best market quality of all lots was obtained in a sealed 250 gauge polyethylene liner. This fruit (Table XII: 36°, Lot 1) was of good condition in all respects. The dup- licate lot was seriously affected with carbon dioxide injury after 82 days of storage. These differences were apparently associated with the gas retentive characteristics of the raw liners. i 5 Jonathan spot was practically controlled in the sealed : liners. It was serious in the folded liners at hO°F where i ;% it affected 13 to an percent of the stored fruit. It also Ki developed in the folded liners at 32 and 36°, but in minor m'“’ amounts. Soft scald developed only at 32°F. Over 50 percent of the fruit were affected in the folded liners and h to ll percent were affected in the sealed 150 gauge polyethylene. The sealed Saran and 250 polyethylene prevented soft scald development. Apples stored in sealed liners developed alcoholic or other off-flavors in many instances. In general, these off-flavors developed in atmospheres in which the oxygen levels were below 2%. Certain exceptions. such as lot 2 of sealed Saran at 32°F, developed an alcoholic flavor even though exceptionally low oxygen nor high carbon dioxide levels were recorded. Mealiness at the end of theaztorage period developed only in the u0°F lots of folded 250 gauge polyethylene. 59 After 10 days, however, the fruit stored at 32 and 36° in this material also showed signs of mealiness. Some meali- ness was found in 150 gauge polyethylene at each storage temperature. No mealiness was found in fruit stored in sealed 250 polyethylene or Saran. The ground color and flesh firmness of apples removed from storage on March 20 are summarized in Table XV. The pressure test data show that fruit stored in the non-sealed V liners at all three temperatures had softened more than fruit in the sealed liners. The degree of softening in these folded liners was inversely related to the storage temp “WV perature. The firmest fruit on March 20 was that sealed in polyethylene 150. As with the pressure tests, the fruit in the unsealed liners generally was lower in ground color rating than fruit in sealed liners. Low temperature reduced yellowing in the folded liners; whereas, in the sealed liners, green color retention was greatest at the high temperature. Soluble solids, pH and titratable acidity of apples removed from storage on March 20 are given in Table XVI. Prior to storage, a random sample of SO apples averaged 13.25 percent soluble solids. After 5 months storage, the soluble solids of the fruit stored in the folded liners ranged from 11.3 to 13.7 percent, and fruit in sealed liners ranged from 13.0 to 1h.8 percent. No relationship of soluble solids to storage temperature was evident, but there was a tendency 60 .moHade om mo msoH wH>oo A»... Fall. On vuwdcwum and no dho>< I.NV doUEOOOA noz.l MN .0 .Gdh UOuGCHEHOB I “V 00 H no.H oH.H om.onm.mH m~.onm.oH oo.one.oH m eoeHoa oo.H o. . 1.. . . . a on o. a H Ha H ma.o+m mH oo.one mH oo.ono NH H omm onoH a» H m oo.~ mm.H n . H 1H.oH uh. .HV em.Hum w ma.o+ _ om.o+ mH m eoHsom om.m oo.m om.N ::.dflo.mH 0H.HHH.mH g.onJH H .omH oconfipohHom om.m fl mu :3: «V «V m . mo.H+ oeHsom on m om.H mo.H :~.ouo.oH oo.ons.mH :m.onm.mH H .omm ocuHansoaHom SH HQ 3 . L6H 3 «V m 00 H+ omHmom .CGAem :3 4V fl 8.0%.3 «V mu H moo: moon m.mm moo: moon momm poH socHH wansm 90Hoo 0:30am .MV Amocdomv apnea enamueam mmoH .ow meme: ca mmm mamas 94 ammoam mmqmma zN mgmN mqm