IHLHWHI \ W l | \l W HM I“ l I 121 896 .THS THE mammsauw iéifi ASQGRLEEC ACSE RET‘E‘I‘ “510% Q? TREE} {23523135 AND GEUEEN EEMKES EEREEE: ‘V’E’J '3‘! #305113 METE'E BS {3% CAHééiE‘éG; rs; 2mm, agwmmz‘zz~é$ ma mama Thesis far the Degree of M. S. MECHAGAN STATE CGHEGE Mei-Po Leu Piaf: 1950 ‘ Ir— ' firvwn' —"r— I I o This is to certify that the thesis entitled THE PALATABILITY AND ASCORBIC ACID RETENTION OF RED CHERRIES AND GREEN BEANS PRESERVED BY HOME METHOIB OF CANNING, FREEZING , DEHYDRATING AND SALTING presented by Mei-Po Lou Plan has been accepted towards fulfillment of the requirements for MASTER' 8 degree in Department of Foods and Nutrition School of Home Economics QALCQK Major professor Datemu. log/£9 ‘_. - w..- u I 1 I D 2 I 0 : .L‘ THE PALATABILITY AND ASCORBIC ACID RETENTION OF RED CHERRIES AND GREEN BEANS PRESERVED BY HOME lEI‘HODS OF CANNING, FREEZING, DEHYDRATING AND SALTING Mei-Po Lou Pia; A THESIS 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 MASTER OF SCIENCE Department of Foods and. Nutrition School of Home Economics 1950 ACKNOWLEDGMENT The writer wishes to express her sincere gratitude to Dr. Pauline Paul, Associate Professor of Foods and Nutrition, Michigan State College, for making this in- vestigation possible. Dr. Paul who suggested this prob- lem to the writer has given unfailing direction and offered every possible help during the course of this BtUdye Thanks are also due to Dr. Dena Cederquist, Miss Ruth Ingalls, Mrs. Annabell Jubb, Dr. Pauline Paul and Mrs. Helen Tobey, who served on the scoring panel. *##***#*** *#***#** *t##** *tt* t. * “fifl’lig TABLE OF CONTENTS IBTTRODUCTIONOOOOO0..OOOOOOOOOOOCOOOOOOOO0....OIOOOOOOOOOOOOOOOOOOC LITERATUE .REVIENQOOOOIOOOOO00.0.0000...O...OOOOIOOOOOOOOOOOOOOOOO Processing Methods........................................... Freezing................................................ Canning................................................. Dehydration............................................. Saltlng................................................. Effect of Processing Methods................................. Ascorbic Acid Retention................................. Flavor and Texture...................................... Coloroooooeeecooeooeoooooeoceeooeoeoeoooeeooooooooooeeco EXPERITJLJIJIAL PROCEDUREOO00.00.000.000...OOOIOOOOOOOOOOOO00.0.00... Red Cherries................................................. Unprocessed............................................. Frozen.................................................o Canned.................................................. Dehydrated.............................................. Green Beans.................................................. Unprocessedoeeoooeoeeoeooooooeoaeeoeeoeeeeeeeeooeooso... Frozenoeeoeooeoeoeooeoooeoeeeeeooeooeeoeeooeeoeeeeeooeoo Canned.................................................. Dehydrated.............................................o Brinedooecocoooeooooeooocooeeoecoooooooooooooeeoeeeoooeo Dry-salted.............................................. Analytical Methods........................................... Ascorbic AC1deeoeooeoeeeeoeeeeeeeeoeeeeeeeoeeeoeeooeoeoo llOiStureooeeoeocooooooeeoooeeeoeooeeooooooeoeeeoeooooeee colorOOOOOOOOOOOOOOOOOOO‘COOCOOOOOIOOOOOOOOIOOOOCOOOOOOO PalatabilitYOOOOOOO0.0.0.0...OOOOOOOOOOOOOOOOO00.0.00... RESULTS AND DISCUSSION...........................................o Comparative Lengths of Time Spent in Processing.............. Yield Of Processed PrOduCtSOOOOOOOOOOOO0.0.0.0...00.0.0000... Palatability SCOr68.........................................o Red Cherries............................................ Green Beans............................................. Color Measurement............................................ Red Cherries............................................ Green Beans............................................o Ascorbic ACid.O00......0.00.0000......OOOOOOOOOOOOOOOOOOOOOO. Effect of Freezing...................................... EffeCt Of Canning....................................... Effect of Drying........................................ EffOCt Of Saltlng........................o.............o Ascorbic Acid in Liquid Portions........................ Page 1 mummqmpmmm 145A 16 16 16 17 17 18 18 18 18 19 19 20 20 20 21 21 22 24 24 25 26 26 29 3O 30 33 34 34 37 37 38 38 Page SLUITV‘TARY ABTD CONCLUSIOIESOOOOOO0.0.0.0000...COOOOOOOOOOOOOOOOOOOOOO. 39 LIST OF WEMTCmOOODOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 41 44 APPEE‘IDIXOOOOOOOOOOO0....OOOOOOOOOOOOOOOIOOOOOOOOOOOOOOO0.0.0.0.... INTRODUCTION The preservation of foods is of increasing interest in the home and on the farm due to its immeasurable influence on daily life. Men turned their thoughts at a_very early time to devising means of preventing foods from spoiling. They began with the storage of seeds and grains in crude store houses as a protection against birds, animals and the weather. Later the preservative effects of cold, dehydration and salt were discovered and other methods gradually fol- lowed as canning and freezing. Drying is probably the oldest method. The ancient Egytians and Arabs dried figs, dates, grapes and olives. These are mentioned in ancient writing. However, dehydration by care- fully controlled conditions of temperature, air-flow and humidity is relatively new. Salting is the next oldest method. Salt preservation is a good method of saving vegetables because the process is simple and inexpensive. In 1809 Nicholas Appert discovered the art of canning. Canning has been the most common method of preserving and storing foods for home use ever since. .Artificbd freezing is the most recent method. It has been used on a commercial basis since 1930, but has only been recently applied to food for home use. Both ancient and newer methods are all widely used today. There still is a question as to how fruits and vegetables should be preserved in order to obtain the best product and still retain as much of the vitamins as possible. As there is little experimental work done for the above question it is felt that investigations in this field are needed. -1... The purpose of this study was to compare the relative merits of home canning, freezing and dehydrating of Montmorency cherries and Landreth Stringless Green Pod Snap beans. Salting was also used for snap beans. The factors evaluated in comparing products preserved by each method were palatability and ascorbic acid retention and the effect of six months storage on these factors. The color change of each product varied to different extent with different methods. For this reason the measurement of color retention is important, and so objective as well as subjective color measurements were made on the products. LITERATURE REVIEW Processing Methods Freezing Freezing is the use of low temperature to prevent harmful yeast, molds and bacteria from growing. Low temperatures do not sterilize the product. The microorganisms are ready to grow in foods as soon as the temperature becomes favorable. Therefore certain directions for handling and preparation as given by previous investigators should be followed. Selection 93 Materials The Extension Service of Michigan State College (1948) recommends Montmorency red cherries as the only desir- able variety for freezing. Stringless Green Pod Snap beans is one of the suggested varieties for freezing. All fruits and vegetables used should be of best quality. Freezing retains the goodness but will not increase it in any product. Preparation and Treatment: Winter (1945) found cherries had better texture and flavor if sweetened before freezing. This may be done by mixing them with dry sugar or by packing in sugar syrup. Cruess _e_t_ El (1948) reported that sugar had a protective effect in re- ducing loss of flavor, color and aroma in red cherries during freezing storage. Experiments were made by him to determine the relative ef- fects of syrups of various sugar content on changes of frozen cherries. The results showed syrup of forty degrees Brix was preferred to those of higher and of lower densities. The Bureau of Human Nutrition and Home Economics (1946) advises that green beans should be blanched to -3- lessen the action of enzymes. Enzymes cause food to lose vitamins as well as flavor and color even after freezing. Blanching also bright- ens the color and softens vegetables, making them easier to pack. Vegetables after blanching should be chilled immediately. This stops the cooking and cuts down the chance for spoilage organisms to grow. Freezing and Storaggs The Bureau of Human Nutrition and Home Economics (1946) suggests that the packed products should be frozen immediately. Any delay would cause loss of color and flavor. A temp perature of ~10° F. or below is usually used for freezing. The best result would be obtained when the storage temperature was maintained near 0° F. ‘Winter (1945) found that the difference in products stored at 00 and 5° F. was not great, but every degree above 50 F. shortened the storage period, accelerated the loss of vitamins, and hastened the loss of attractive color in green vegetables. Long-continued stor- age should not be attempted at any temperature above 10° F. Certain microorganisms were capable of growing at low temperatures but very few grew below 19° F. The lowest limit for growth was believed to be about 14° F. Cooking: Winter (1945) also suggests that thawing foods are wet foods and are subject to attack by spoilage organisms. Therefore fro- zen food should remain in the unopened container during thawing or should be cooked promptly after removal from.freezing temperature. Canning The principle of canning is to heat the foods hot enough and long enough to stop the action of the enzymes and to destroy the spoilage organisms. The successful use of a canning method depends on the following factors. Selection 2: Material: The Bureau of Human Nutrition and Home Economics (1947) advised that fruits and vegetables for canning should be fresh, sound and firm. Griswold (1944) found cherries can- ned immediately after picking had a redder, more intense color and tasted better than those held four days at 41° F. or those held at 84° F. for 24 hours before canning. Preparation and Treatment: Green beans should be boiled in boil- ing water and packed hot wdth cooking liquid and salt. Sugar should be added to cherries before heating to draw out the juice. The effect of different proportions of syrup was tested by Griswold (1944). As the percentage of sugar increased from zero to 70, scores for the vari- ous palatability factors increased at first and then decreased at the highest concentration. The judges preferred fruits canned in 40 or 45 percent syrup. She also showed the objective measurement indicated that sugar syrup prevented the loss of color during canning rather than during storage. Processing: Griswold (1944) observed that a wide range of pro- cessing times, 10 to 45 minutes, resulted in little variation. Cherries processed 10 minutes did not seem spoiled and those processed 45 minutes compared closely with those processed for the standard 25 minutes. Storage: Gruetzmacher (1948) recommends the storage temperature of 45° to 600 F. for canned jars in dark and dry places. -5- Dehydration Dehydration means to remove water. Dehydrated foods have their water content reduced to such a degree that they may be stored indefi- nitely. The water must be removed in such a way that the highest pos- sible food value of the products is preserved. Selection pf material: Both Stringless Green snap beans and Mont- moreney cherries are considered by the Georgia Home Food Preservation Committee (1946) as the right varieties that yield nice dehydrated products. Preparation and Treatment: Green beans should be blanched before dehydrating. The effect of blanching on the drying rates of green beans was studied by Sugihara and Cruess (1941). They concluded that blanching caused an increase in.the rate of drying. Crafts (1944, p. 451) summarized the beneficial effects of blanching prior to drying as follows: "1. Intercellular air acts as an insulator restricting inward movement of heat and outward movement of moisture. Experience has proved that blanched products dry more quickly than un- blanched. 2. Air trapped in drying tissue contains oxygen that may re- act with ascorbic acid . . . . Blanched fruits retain their vitamin C content longer than unblanched . . . . 3. Though the change in appearance upon blanching may not be primary importance, it is an index of complete penetration of heat. Such penetration brings about at least two beneficial reactions: first, it inactivates certain enzymes; second, it softens cell walls and improves the texture of the cooked product . . . ." There are some supplementary treatments for cherries to prevent the loss of red color when cherries are dehydrated.“ Alderman (1945) described the use of 0.05 per cent of sodium.bisulfite to soak cherries for 30 seconds prior to dehydration to aid in preserving the color. -5- Cruess (1942) reported that good quality dehydrated cherries were ob- tained when cherries were sulfured prior to dehydration. Processing: According to the suggestion of Bureau of Human N- - trition and Home Economics (1942) the best temperatures of drying fruits and vegetables are between 125° and 160° F. The temperature should be lower with high humidity in the first half of drying to pre- vent case hardening. Finished Products: The Bureau (1943) also stated that the dehy- drated snap beans should be brittle, greenish black, and the cherries should be leathery but sticky. Packing and Storipg: Dehydrated products should be packed in air- tight, moisture-proof glass jars and kept in dark and cool place. Weigand 32 3.1 (1945) reported that cherries stored any appreciable time at 95° F. showed marked darkening in color whether sulfured or not. Rehydration: Alderman (1945) soaked the dehydrated cherries in water for so minutes at temperature of 175° to 180° F. and then brought to a boil for three minutes. His result was quite satisfactory. Salt ing Salting draws water from vegetables by the process of osmosis, forming a brine that inhibits the growth of spoilage organisms. Green beans can be salted in two ways: 1, with brine and 2, with dry salt. Selection 93 Material: Etchells (1943) reported that salting could be adapted to preserving non-acid vegetables as cabbage, green beans and peas. Preservation and Treatment: Etchells (1943) found that green beans blanched prior to salting had better flavor and texture than the unblanched lots. Fabian (1943) wrote that blanched beans fer- mented more readily than.unblanched ones. Processing: Fermentation occurs in brining and salting beans. Loomis (1863, p. 473) explained the fact of fermentation as follows: "The fermentable sugar present in all fruits and vegetables, which is one of the soluble substances extracted by osmotic action, serves as food for lactic-acid bacteria. The growth of lactic bacteria produces a fermentation. The acid thus formed acts upon the vegetable tissues bringing about the changes in color, taste and texture which mark the pickled state. A scum will form on top of the brine in a day or two and this should be carefully skimmed off daily, as it tends to destroy the acidity, break down.the vegetable, and weaken the acid content. The best temperature for curing is be- tween 75° and 85° F., and this will require from 10 days to three weeks. Too low temperature retards fermentation and too high temperature during the period may cause ropy brine and spoilage of the product. 'When bubbles cease to rise, fermentation is complete." Repacking: Etchells said that fermented material should be re- packed into canning jars and processing in boiling water bath to pre- vent undesirable changes in the material that might occur if not processed. Storage: Fabian (1943) recommends to store salted products at room'temperature. Effect pf ProcessingMethods Ascorbic Acid Retention Vegetables and fruits are subject to some chemical and physical changes during processing. Ascorbic acid is one of the vitamins af- fected to a great extent. Previous investigations have shown that different processing methods have different degrees of effect on ascor- bic acid content. Freezing: Farrell (1942) found the blanched Landreth Stringless Green Pod snap beans lost 33 per cent of their ascorbic acid on freez- ing. The unblanched ones only retained 10 per cent of their original content of ascorbic acid. Kirk and Tressler (1941) explained that heating caused an inactivation of ascorbic acid oxidase and thus inhib- ited further oxidation of ascorbic acid. Blanching also resulted in the loss of dissolved air. Hummel (1942) showed that in vegetables blanched at 930 C. for one minute, the oxidase was destroyed and only about 15 per cent of the ascorbic acid was lost. With rapid packing and freezing there was no further appreciable loss. Jenkin, Tressler and Fitzgerald (1938) reported that freshly cooked vegetables and frozen cooked ones had about the same ascorbic acid content, since the cooking time was materially shortened for the frozen food which was blanched prior to freezing. Fitzgerald and Fellers (1938) found the average content of ascorbic acid of frozen green beans was 0.065 milli- gram per gram of wet basis which was about one half the ascorbic acid of fresh market beans averaging 0.13 milligram per gram. Kirk and Tressler (1941) considered Montmorency cherries as a very poor source of ascorbic acid. They found the average content of ascorbic acid of the raw samples of these cherries was 0.09 milligram per gram. They also described that ascorbic acid content was inversely proportional to the amount of sugar added even when compared on a sugar-free basis. This might be caused by oxidation.by air incorporation while stirring in the sugar. Cruess (1948) learned that relatively little loss occurred in ascorbic acid during freezing if the temperature was at ~10° F. or lower, but 16 to 50 per cent of ascorbic acid was lost in the blanching of vegetables and infthe cooling of fruits before freez- ing. NbIntosh (1944, p. 145) summarized ways to reduce the loss of ascorbic acid in vegetables processed by freezing as follows: "1. Harvest at optimum maturity and process immediately. 2. Use correct blanching period for each vegetable. 3. Cool quickly after blanching and package. 4. Freeze and hold vegetable at or below -18° C. 5. Frozen vege- table may be defrosted to room.temperature before cooking but do not thaw completely or allow them to stand partially defrosted for any length of time. 6. Cook as quickly as possible in a small amount of water. 7. Serve immediately." Canning: Bedford and MbGregor (1948) showed that ascorbic acid retention was greater in unblanched canned green beans than in blanched ones. No differences were noticed in palatability and color of the canned beans with and without blanching. Hayfield and Richardson (1939) reported that snap beans in the fresh, raw state were a good source of ascorbic acid. They showed that when the vegetable was boiled for 45 minutes, a 30 to 40 per cent loss of ascorbic acid occurred. Eighty to 85 per cent of the ascorbic acid was lost in canned snap beans which were stored at room.temperature for eight months. If beans after cooking were allowed to stand one hour before testing they lost an addi- tional 10 per cent of their ascorbic acid content. They also showed that canning process was no more destructive of ascorbic acid than.the process of boiling in an open kettle. 'When the canned beans had been stored two months at room temperature the total loss of ascorbic acid content was increased to seventy per cent. An additional ten per cent of the original ascorbic acid was lost from three to eight months. -10.. At the end of eight months these beans were found to contain 0.04 milligrams of ascorbic acid per gram on wet basis. Guerrant 32 El (1946) found the commercially canned Montmorency cherries retained an average of 96 per cent of the original ascorbic acid (dry weight basis), but canned green beans retained only 41 to 60 per cent. Shmidt (1941) reported that canned cherries had a retention of ascor- bic acid as high as 90 to 100 per cent. He noted that the greatest loss of ascorbic acid occurred from.the time the fruit was plunged into the boiling water to that time when the boiling point was again reached. Dehydration: Farrell (1942) found dehydration of green beans resulted in almost total destruction of ascorbic acid. Eheart and Sholes (1945) dehydrated two lots of green beans. One lot was blanched before dehydration, the other lot was without blanching. They reported the retention of the dehydrated product of the unblanched lot was 0.01 milligram per gram and that of the blanched lot was 0.21 to 0.27 milli- gram per gram. They considered that even the blanched lot was a poor source of ascorbic acid after dehydration, since only 6.9 per cent of the amount in the raw beans remained in.the dehydrated product. They also described the methods of storage of dehydrated products caused significant differences in retention of ascorbic acid during six months of storage. Dehydrated beans stored in refrigerator in cello- phane bags or in fruit jars contained significantly more ascorbic acid, averaging 0.19 and 0.21 milligram per gram.dry basis respectively, than beans stored in cellophane bags at room.temperature which con- tained only 0.09 milligram. Cruess (1942) found there was large loss -11.. of ascorbic acid in the drying of fruit unless the fruit was sulfured. He explained that in some fruits such as apples, prunes and berries, oxidation of ascorbic acid was greatly accelerated by ascorbase, an enzyme found in the flesh of these fruits. If the enzyme was des- troyed by heat or was held in check by sulfur dioxide or other power- ful anti-oxidant, ascorbic acid would be much better retained. Salting: Peterson, Mack and Athawes (1939) observed about a 50 per cent less in ascorbic acid during fermentation of shredded cab- bage and a further 20 per cent less in canning. A protection of sauerkraut from air retained the ascorbic acid content. The loss of ascorbic acid in vegetables seems to be associated with the loss of carbon dioxide after fermentation is complete. Hummel (1942) showed when sauerkraut was made of fresh cabbage and fermented quickly it lost little ascorbic acid but as soon as fermentation with its atmos- phere of carbon dioxide ceased, a steady decrease in ascorbic acid took place. He concluded that in fermentation ascorbic acid was not destroyed directly by most yeasts or bacteria but was subjected to loss by oxidation. Blum and Fabian (1942) described the green beans that were blanched and then salted lost more ascorbic acid than did unblanched. The losses of ascorbic acid varied from 64 to 86 per cent for whole green beans in unblanched samples and from.66 to 89 per cent in blanched samples. Etchells (1943) reported an average of 15 per cent of ascorbic acid was retained in all lots of salted beans after two months at either room.or refrigerator temperature. -13- Flavg£_and Texture Little has been reported by the previous investigators about the _ effect of various processing methods on the flavor and texture changes of green beans and cherries. 'WOodroof and Shelor (1948) froze green beans at ~15° F. and stored them.at -l5°, 0° and 15° F. Green beans stored at -15° F. were scored the highest on texture and flavor, those stored at 15° F. received the lowest score. A stale or hay-like flavor developed in those beans stored at 15° and 00 F. by the end of eight months and became much worse by the end of the year. Griswold (1944) noticed a decline in flavor and texture of canned cherries for all variations during the course of seventeen.month storage period. The variations were canned cherries stored in dark at room.tempera- ture, stored in light at room.temperature and kept in cold storage at 500 F. The flavor of cherries stored at 50° F. Was rated far ahead of the samples stored at room temperature. There was little differ- ence in the texture of the samples. Alderman (19‘5) showed that de- hydrated red cherries lost the ability to rehydrate satisfactorily after six months' storage. Fabian (1941) found fermentation had no deleterious effect on the flavor and texture of green beans. Etchells (1943) reported that green beans blanched prior to salting possessed better flavor and texture than the unblanched lots. Color Color is one of the properties of fruits and vegetables affected by processing and storage, especially that of highly pigmented food like cherries and green beans. Feaster (1949) found that in ordinary canning procedure the chlorophyll in beans decomposed partially, re- sulting in the loss of the characteristic green color. There was also a continuous decomposition of chlorophyll during storage. The rate of color loss was a function of temperature, and storage at low'temperature was desirable for maximum.color retention. At normal temperature, 21° C. or lower, changes in.the color of most processed products were not of great significance. However holding of processed foods at abnormally high temperature was accompanied by loss of the characteristic bright colors of foods and development of dull and darkened shades in the light-colored products. Griswold (1944) des- cribed that canned cherries stored in.a cool, dark place retained their color well during the long storage period, while the color of samples stored at room.temperature became yellower and less intense. Canned cherries stored in.the dark retained their color better than those stored in the light. Woodroof and Shelor (1948) froze blanched green beans at -15° F. and stored them.at different temperatures. They found color changes of frozen green.beans were much greater at the higher temperature. The beans became gray and yellowish at 15° and 0° F.; there were only slight loss of blue and increase in.yellow color at ~15o F. Lueck 32 El (1941) established that low oxygen con- tent of food products assisted in retarding formation of undesirable colors. However, Feaster (1949) reported that oxidation was not the only factor influencing the color change during storage. Fabian (1943) found that fermentation of green beans destroyed the chlorophyll con- tent to a great extent; further loss of color on storage was not noted. Alderman (1945) showed that dehydrated red cherries deteriorated in -14- color, resulting in a reddish brown product; when rehydrated there was a decided loss of red color. He found that the use of 0.05 per cent sodium.bisulfite solution to soak the fruits prior to drying helped to preserve the color by preventing bleaching of the antho- cyanin pigment upon rehydration and cooking. Anthocyanin is the principal pigment of cherries. Any change of color is the result of change of the anthocyanin pigment. -15- EXPERIMENTAL PROCEDURE The Hontmorency red cherries and the Landreth Stringless Green Pod snap beans used in this study were grown under the supervision of the Department of Horticulture, Hfichigan State College. They were picked at a suitable state of maturity for eating and were brought to the laboratory immediately. Ten pounds of cherries were washed and pitted at one time. Twenty pounds of beans were prepared at one time. The remainder was kept under refrigeration until used. Cherries were processed by three different methods: freezing, canning and dehydration, and green beans were processed by five dif- ferent methods: freezing, canning, dehydration, brining and dry- salting. Analytical determinations were made on unprocessed, freshly processed and stored samples. The length of time spent in prepara- tion and processing was recorded. Red Cherries Unprocessed The cherries were washed and pitted. Seventy-five grams of sugar 'were added to 300 grams of cherries. No water was added since the cherries were very juiey. The mixture was boiled for one minute, then chilled before scoring. Frozen Three hundred grams of cherries were packed in.a‘one-pint carton with 75 grams of sugar, then frozen.at -4° F. (~20° 0.). The frozen cherries were held at this temperature until used. They were prepared -16- for scoring by adding 30 grams of boiling water to the contents of a carton and boiling for three minutes. They were then chilled before serving. Canned Seventy-five grams of sugar were added for each 300 grams of pitted cherries. The mixture was brought to a boil and packed into pint jars. The jars were processed fifteen minutes in a boiling water bath, then cooled and stored at room.temperature. The jars were re- frigerated for two hours before scoring so that all samples would be at the same temperature. Dehydrated Fresh pitted cherries were drained 30 minutes, spread one layer deep on 16" by 22” screened trays, and dehydrated at 1400 to 1670 F. (60° to 75° C.) in a Top-of—the-stove-drier. An electric fan.was used to blow toward the top of the dehydrator so as to improve the ventila- tion. The temperature reached 176° F. (80° C.) for a short time near the end of the dehydration period, at which time the cherries became leathery and sticky. The dehydrated cherries were packed in pint jars and kept at refrigerator temperature of 40° to 44° F. The dried cherries were rehydrated by soaking in water in a double boiler at 140° to 176° F. (60° to 80° c.) for thirty minutes. The amount of water added was figured out in.such a way so that it would bring the dried cherries back to the original fresh weight. It was found out in this experiment that 0.15 pound of dehydrated cherries was equivalent ‘to one pound of fresh ones. Seventy-five grams of sugar were added to -1 7- each 300 grams of rehydrated cherries and the cherries were placed directly over the flame and boiled vigorously for three minutes. They were then chilled before serving. Green Beans Unprocessed The fresh green beans were wathed, snapped and cut into inch pieces. Half teaspoon of salt and one cup of water were added to half pound of these fresh green.beans. The mixture was boiled for ten minutes and served hot. Freshly prepared green beans* were blanched for three minutes, two pounds at a time in.two gallons of boiling water. They were drained, then cooled promptly in running cold water. Two hundred and fifty grams of blanched beans were packed without salt in each pint package. They were frozen and kept at-4° F. (-200 C.) until used. To prepare for'scoring, each package of beans was turned into a sauce- pan containing three—quarters of a cup of boiling water with half teaspoon of salt. They were boiled for five minutes and served hot. Canned Sixteen pounds of freshly prepared beanst were covered with boil- ing water and boiled for five minutes. They were then packed in pint jars to within half inch of the top and covered with hot cooking liquid. Half teaspoon of salt was added to each pint of beans. *Freshly prepared beans are beans being washed, snipped and out into inch pieces. The jars were closed and processed under ten pounds pressure (2400 F.) for twenty minutes. The canned beans were stored at room temperature in a cupboard. They were brought to a boil for ten minutes before being served for scoring. pghydrat ed Freshly prepared beanst were blanched in steam.for twenty minutes and dehydrated at 167° to 185° F. (75° to 85° C.) in a top-of—the- stove drier in.the same manner as for dehydrated cherries. The dehy- drated beans were packed in pint jars and stored under refrigeration. They were rehydrated by adding three cups of water and half teaspoon of salt to each 60 grams of dried beans. The mixture was covered and brought slowly to a boil, cooked for thirty minutes, and served hot. Brined Freshly prepared beans* were blanched, two pounds at a time in two gallons of boiling water, for five minutes. They were drained and cooled promptly in cold water. The blanched beans were packed firmly into a 5-gallon crock. Several layers of clean white cheesecloth were used to cover the beans. Then the top was weighted with a plate and a piece of stone and the crock filled with one and a half gallons of brine. The brine was prepared by mixing half pound of salt and eight ounces of household vinegar to each gallon of water. The beans were stored at room temperature (70° to 80° F.) for two weeks. The scum was removed and cheesecloth changed every other day. At the end of this period, the beans were repacked into pint jars and processed in *Freshly prepared beans are beans being washed, snipped and cut into inch pieces. -19.. a boiling water bath for twenty-five minutes. They were stored at room temperature in a cupboard. The brined beans were soaked over- night at the rate of one gallon of water for each pound of beans in order to remove the salt. They were then brought to a boil in a small amount of fresh water and served hot. Dry Salt ed The preliminary treatment for fresh green beans through blanching was the same as for brining. Half pound of salt was evenly mixed with each ten pounds of blanched beans. They were then packed in a con- tainer, covered with several layers of cheesecloth and weighted down with a plate and a piece of stone. Eight ounces of household vinegar for each ten pounds of beans were used to cover the beans. The rest of the treatment from weighting down was the same as for brined beans. Analytical Methods Analyses were made on samples at different stages: 1) raw, 2) freshly cooked, 3) freshly processed and 4) after storage for two, four and six and a half months. The canned, brined and salted and frozen products were analyzed as stored. The dehydrated products were rehydrated before analyzing. The drained weights for rehydrated, Canned and salted products were determined after draining for two minutes in a colander. iscorbic Acid The method of Loeffler and Ponting (1942) was used for the ascor- bic acid determinations. One hundred gram samples of both liquids -20... and solids were us ed. Samples of frozen products were taken right from the freezer. Samples of canned and salted products were taken from the jars. Samples of dehydrated products were taken as they were first rehydrated. Analyses were made in triplicate. Moisture The samples for moisture determination were chopped and dried to constant weight in an oven with forced draft ventilation at a tempera- ture of 158° F. (70° C.) for forty-eight hours. A semi-automatic moisture testernI was used for the moisture determination for the later part of the experiments. The temperature was set at 258° F. (120° 0.). Bean samples were dried for two hours and cherry samples for five hours. Color The color of the samples of both cherries and beans was meas- ured objectively by the use of Mans ell color disc according to the method described by Good (1948). The sample was packed down in the sample cell to avoid large empty areas on the cell surface, some liquid was used to fill the gaps. The colors of the green beans were Compared with 1Munsell color discs: Nl (black), N5 (grey), GY5/8 (green-yellow), and YRS/12 (yellow-red). For red cherries, N1 (black), N5 (gray), R3.8/l4 (red) and YR6/12 (yellow-red) were used. #Brabender Semi-automatic Moisture Tester, manufactured by Brabender Corporation, Rochelle Park, N. J. -21- Palatability Samples of each lot of beans and cherries were cooked and scored 'to determine the palatability. A panel of judges assisted in each 'test. The products were scored according to the chart shown in Figure I. -22- .mwonaflsofi .muonhnw .wQ«nopmom ones: no muonapndam .Hdaaevde snowman mo oodomcam .mmonnwsop .oHSpHoe .wnaXOeH nobeHm Heazpsn .unowndnvmd no .nsom cop .peokm oov .nosBHm mmo no nwuonou his «noseam .uoousononm pod Loco Heunpdn .mnouo Heunvann: nonpo no douavauo .nomo .codpsuoaoouwu nosvo and .wqansonp .mmoeHHse .wnwnouudu no madden «uoaoo .nOHPAOQ peace saga ewsvda mo noapdnemom cease .moonmm nH .opo .meaxm mo weaswsoam .waammdflaoo .wcHHMnaak..wnaM:«ugm ounce «oocdhsommw Heaonow «haueanowpudm open on upcomon poem much noon pawn _Bsaeoe voow voow much w pnoaaooxfl I b m I I I I “'31:!!an hem wnauoo 02 no no» u onwpmooo< doweeHoqowaMhoneu onspxoa ____¢L - nebuHm p eeeo ’"F"'"[“"“""F-"“"( aOHeo condueommd Heuonou . 1...”-.. - L-._..-7L--~.~_4Le- .. F. L,_ML-WQ_HM r- --—-—-_-1-.. .mmmweHgadm open moanevowob use spasms nououm pom undo choom H HMDUHm csdz - 3 2 n RESULTS AND DISCUSSION Tables 1 and 2 show the time spent in preparing and processing one pound of raw material by the various methods. Dnying took almost four and a half times longer than freezing and nearly two and a half times longer than canning for the same amount of raw cherries. A pound of raW'cherries took eighteen minutes for washing and pitting and one minute to mix with sugar and package for freezing. Twenty minutes were required to prepare and pack one pound of raw green beans for freezing. Canning took about twice as long as freezing, and drying three times as long. Both brining and salting required less time than canning but more time than freezing. Table 1. Average lengths of time spent in preparing and processing red cherries. (minutes per pound per person) Preparation Processing Total stemming & pitting Frozen 18 1 19 Dried 18 70 88 Canned 18 16 34 Table 2. Average lengths of time in preparing and processing green beans. (minutes per pound per person) Preparation Processing Total snipping & cutting Dry salted 17 12 29 Brined 17 11 28 Frozen 17 3 20 Dried 17 44 61 Canned 17 20 37 Yield 22 Processed Products Table 3 shows the yield of processed products from the same amount of fresh material. Dehydrated products required the least space to store. Frozen cherries yielded 16 pints (about 50 per cent) more than canned cherries from the same amount of raw material. The frozen ones were not ‘blanched'while the canned ones were brought to a boil before pack- ing. This heating process softened the fruit tissue so that they pack- ed more easily and consequently did not take as much space. The same amount of green beans produced 4 pints (about 10 per cent) more as canned than as frozen beans. The beans for freezing and for canning both received a short cooking before packing, so they packed and yielded about the same number of jars from a given weight of vegetable. Blanch- ing causes the shrinkage of the beans and the expulsion of gases from -25- inside the vegetable tissue. Both brined and dry-salted beans had about the same yield as the canned products. Table 3. Yield of processed products Food Fresh Frozen Canned Dehydrated Brined Dry-salted lbs. pints pints lbs. pints pints Cherries 50 46 30 4.5 Green Beans 20 36 40 2 42 42 Palatability Scores The mean scores for cherries and green beans are shown in Tables 4 and 5. In general, palatability declined with storage. When the flavor is rated low, no matter how high other factors are graded, the general conclusion is also rated low; The color data are related to the scores for odor and flavor showing that a sample which receives a high score for color would probably be scored high for odor and for flavor. The judges consistently preferred the frozen products to the products processed in other ways. Cherries The treatments caused differences in general appearance and color. Both freshly canned and frozen cherries were rated higher than the freshly cooked samples. Dried cherries were rated very low. A complete rehydration of dried cherries was impossible. The rehydrated dried cherries looked shrunken and dark, and had lost the characteristic red color of cherri es. Table 4. Average scores for palatability factors of red cherries for different treatments and storage periods. (maximum possible score - 7) 7' 7 Treatment ‘Freshly 1 Frozen Dried ‘ Canned cooked F.P.* Stored F.P.* Stored F.P.* Stored 3 (months) ‘A (months) L_ (months) 4‘ ‘ 2 4 6% 2 4 6% 2 4 6&7 (17 (17 (2) (1)7317 (17 00 (URI) (4) (37 (5L °°n°rail 4.4 5.3 5.5 5.1 4.6 3.9 3.9 3.7 3.0 5.3 4.7 3.5 4.5 appearance h Color 5.0 5.4 5.8 5.1 5.1 3.2 3.7 3.7 3.2 5.5 5.2 4.4 4.4 Odor 6.2 6.7 6.0 5.6 6.3 5.2 5.8 5.0 5.2 5.3 5.3 4.4 4.3 Flavor 5.8 6.4 5.8 5.4 5.5 4.7‘4.6 4.7 4.8 5.7 4.3 3.5 4.2 Texture 5.6 _5.7 5.5 5.5 5.6 4.2 4.5 4.3 3.6 5.5 5.3 3.9 4.9 °°n°ra1 5.5 ’6.0 5.3 5.1 5.3 3.8 4.2 4.4 4.1 5.3 4.1 3.4 4.3 conclusion ; 1 A°°°Ptab1° YiYYYYYYYYYYYY Yes orNo 9 4 Freshly processed. (1) Each number is the average of 12 figures as 4 judges and 3 composites for the experiment. (2) Each number is the average of 4 figures as 2 judges and 2 composites for the experiment. (3) Each number is the average of 10 figures as 5 judges and 2 composites for the experiment. (4) Each number is the average of 9 figures as 3 judges and 3 composites for the experiment. (5) Each number is the average of 15 figures as 5 judges and 3 composites for the experiment. -27- .pnosanomxo esp you mopwmomsoo m use mowusn m as monswwu 0H mo owenobu on» ma honfinn zoom on .pnofiwuomxo onp.nom movwmomsoo m was newezn m we someway ma no omduobu on» on homes: noun Amv .pqosunomxo onp non mopHmOQEoo m use momesn n we mouswflm m we cwenoba onp.m« nomads seem Aev .pnoeauomxo o:p.nom navamomsoo m use mowean e as mouswam NH mo owenoba on» a“ genius zoom Amv .puosuuomxo on» new mouanomfioo m use mowusn m we mouswfiw m mo owenope one a“ nonesn seem Amv .pfioEwucmHo esp mom mopamomsoo m use mowesn e ed someway m we oweaubd on» ma Aeneas zoom Adv candpmoood hashes I I» commooonm hammonm I .m.m es noxooo haemoum I .o.m * n M A 7 H _ e d 7 . , 02 no mowr M w w M H w r z z I» w _ M _ w w M w M H w z I» z w . I» 2 .IM 2 mVLr canepmoood r41 {1 e » nowmsflcnoor o.» H.w m.¢ o.¢ o.m , m.m ¢.N m.n H.w m.¢ m.m ¢.m m.m ¢.m m.m. o.» m.m m.wrm.m m.m. e.» H.m H.w m.w m.mm Heaonow m.¢ m.¢ m.¢ s.¢ ,m.m w New m.m ¢.¢ H.» m.m _ m.m o.m m.m m.w m.me s.w m.m m.m 5.4 m.m o.m m.¢ m.m m.¢ m.mfl manpxoa s.m m.¢ n.¢ m.¢ _m.me m.m m.m m.m m.m ,m.m m.m ¢.m m.m ¢.m m.me m.m m.m m.¢ n.H m.me o.m H.m m.m H.m m.mm nobeam s.» m.» m.¢ s.n m.¢ w e.m m.» m.m s.m o.m o.w N.o o.w w.m m.mw >.m o.¢ m.m e.» m.m H.» m.& m.¢ s.» H.m“ mono w.¢ H.¢ s.¢ N.v .m.w W s.m m.m ¢.n H.m rm.¢ o.w s.m o.m w.m ,m.¢w s.n m.¢ m.n m.¢ m.w m.¢ s.¢ N.¢ m.¢ s.¢w uoaoo nHw _ 17 M . 41,00qendommmu o.m s.¢ o.m m.¢ m.¢ _ m.m o.n o.¢ m.m mm.¢ _ m.m ¢.m ¢.m ¢.m em.m w.m w.¢ s.¢ e.m m.m s.¢ m.¢ m.¢ m.m . rHsnonow m m L3 5 E b3 (.35 Se E E A3 is _ B AS E 53 E E E E ea E ,58 “EB AS 3 two e N rte .0. me e «Intense me e «Jane .0...“ mm e m and 6.47 me e N .mé . pmmmqospvouopm ** _ * mmmsoevwonowmree n * amnpco£VWonopm ** * nnmnospwonowm ** I 4 Rmnmeospmouoym754 em nonndo woman nononm " ecsanm eopHsmIzua As u once» canamnomrasfiwxdav .muoauom oweuopu use nanoapdouv vaoaommfie you mason nooam no unaposm hnwaflndpdflom mom nonoon swapped .m canes The judges made no comments concerning off-odor in any of the samples. Frozen cherries retained most of the characteristic odor while canned and dried cherries kept only a part of the original odor. The odor of freshly frozen cherries was rated the highest but there was a gradual decline in the scores with the lengths of time in storage. The scores of the dried cherries after storage were about the same as the freshly dried. Frozen cherries received the highest scores for flavor and dried ones the lowest. The judges described the dried cherries as being sour and lacking in characteristic flavor. One of the judges said that they were acceptable as dehydrated cherries. The scores for the flavor of dehydrated cherries changed very little with storage but that for both frozen and canned dropped gradually during the 6-month storage. The texture of the frozen cherries was most desirable and that of canned was closely comparable with the freshly cooked fruits. Two of the judges commented on.the toughness of the dehydrated samples. The frozen cherries received the highest average score on general conclusion, the canned was close second. The dried cherries received the lowest score. There was a definite decline in all the general scores with the length of time in storage. All the samples were accept- able to all the judges. Green Beans ‘Frozen beans retained as much green color as the freshly cooked beans and received the highest scores in color and appearance. Dried beans were rated the poorest. The canned, dry-salted and brined beans -29- were rated in between and in order as listed. The judges described the dried beans as being dark and brown. The scores for flavor were highest for frozen beans and lowest for brined and dry-salted.beans with canned second and dried third. One of the judges commented frequently on.the flatness, saltiness and sourness of the salted beans and suggested that unless the salted vegetable was blended with some other food it was not acceptable. The salted vegetables were rated higher in texture than the canned ones which in.turn were rated higher than the dried beans. Frozen beans received the highest scores in texture. The poor flavor of the salted beans had a great effect in the general conclusion. They were not acceptable in.the freshly processed and 4-month stored and barely acceptable in the rest of the periods. Frozen beans were most desirable to the judges throughout the en- tire test period and canned beans second. Dried beans were acceptable as freshly processed, later declined from barely acceptable to not accept- able with storage. Color measurement The results from.the objective color tests on the cherries and beans are shown in Tables 6 and '7. Cherries _‘~—————— The figures for hue of frozen and canned cherries show about the same gradual change from red to yellow-red with increasing time in storage. The dehydrated cherries retained the least amount of red and -30- JL Table 6. thsell color readings of cherriesfl’ Freshly Freshly After storage for cooked processed 2 months 4 months 6fi-months Hue* 6.5 7.2 7.1 7.8 7.0 Frozen Value** 3.5 3.4 3.4 3.2 2.7 Chroma*** 5.8 7.2 5.2 4.7 4.5 Hue 6.5 7.1 7.6 8.6 8.9 Canned Value 3.5 3.1 3.2 5.0 2.7 Chroma 5.8 6.0 5.8 4.6 4.5 Hue 6.5 10.1 10.1 12.4 10.3 Dehy- Value 3.5 206 3.7 206 205 drated Chroma 5.8 1.6 3.4 2.0 2.1 :# Each number is the average of 3 replicate samples. * Hue is the quality that differentiates from.gray of the same value. The hue number of red is 5 and yellowbred is 15. ** Value is the lightness of color. The scale begins at O (absolute black) to 10 (absolute white). *** Chroma is the strength of a color, neutral gray being 0, while higher numbers represent stronger colors. -31- Table 7. Nunsell color readings of green beansi# Freshly Freshly After storage for cooked processed 2 months 4 months E-months Hue* 33.4 34.1 34.3 34.2 33.7 Frozen. Value** 4.3 4.1 4.0 3.8 3.8 Chroma*** 5.4 405 3.9 304 3.5 Hue 34.0 25.2 25.4 24.7 25.5 Canned Value 406 3.9 4.5 3.8 4.4 Chroma 5.5 3.2 5.0 3.5 4.6 . Hue 32.5 23.6 23.6 21.6 23.4 Dehy" Value 4.0 2.7 3.0 300 3.4 drated Chroma 3.8 2.7 1.9 1.9 2.8 Hue 33.2 25.5 18.3 23.9 25.5 Brined ‘Value 4.3 3.8 3.3 4.3 4.0 Chroma 5.4 3.7 2.6 4.2 3.7 Hue 33.6 26.4 19.0 24.0 24.7 Dl'y- value 4.4 3.7 3.4 402 305 salted Chroma 5.5 3.7 3.0 4.2 2.8 =# Each number is the average of 3 replicates. * Hue is the quality that differentiates from gray of the same value. The hue number of yellowered is 15 and greenfiyellow is 35. ** value is the lightness of color. The scale begins at 0 (absolute black) to 10 (absolute white). 44* Chroma is the strength of a color, neutral gray being 0, while higher numbers represent stronger colors. -32- greatest amount of yellowered. Storage did not have much effect on the hue of dehydrated cherries. The freshly processed samples of frozen and canned cherries were darker (1ower value) than were the freshly cocked cherries. Both frozen and canned cherries became darker with storage. Dehydrated cherries had very low values and no marked change was shown during storage. The highest chroma was found in freshly frozen cherries, lower in freshly canned and very low in dehydrated ones. Frozen and canned cherries showed a decided decrease in chroma from the first time inter- val to the last, indicating loss of color with storage. The dehy- drated cherries had the lowest chroma, when.just processed, then the chroma increased slightly with storage. Green Beans All the samples of frozen green beans had higher hue readings than samples processed in other ways. A slight decrease in the greenness of the frozen samples at the end of the storage period was observed. Canned and brined beans contained the next largest amount of green, while the dehydrated and dry-salted beans contained the least amount. The value figures showed that dehydrated beans were the darkest, the freshly cooked samples were the lightest and the rest were about the same. All the samples, except the frozen and dry-salted ones, had a slight increase in value from the freshly processed stage to the last storage stage. Frozen and dry-salted beans became darker (lower value) during storage. -33- Freshly cooked beans had the highest chroma, the freshly frozen ones were second, canned and salted third and dehydrated lowest. Dehy- drated and brined beans showed little change in chroma, but the other samples showed a decrease, with length of time in storage. Ascorbic Acid The results of the ascorbic acid determinations are summarized in Tables 8 and 9. The calculation of dry basis was made from.data on per- cent total solids listed in.Tables 10 and 11, Appendix. It is evident that red cherries and snap beans after processed decreased in ascorbic acid content in different degrees with various treatments. Effect ganreezing Freezing had less effect on ascorbic acid retention than any of the other methods tested. Both frozen cherries and beans had the least loss of ascorbic acid in comparison with the products processed in other ways. The retention of ascorbic acid in freshly frozen cherries was 73 percent on wet basis which was higher than.that for freshly cooked ones. One reason.may be that frozen cherries were not blanched and were packed raw with sugar before packing for freezing. The 27 percent loss of ascorbic acid of the freshly frozen cherries was due to freezing process while the 35 percent loss of ascorbic acid of the freshly cooked samples was due to cooking. This showed that freezing had less effect on ascor- bic acid retention in cherries than cooking. -34- Table 8. Effect of freezing, canning and dehydration on ascorbic acid content of Montmorency cherries. Ascorbic acid per 100 grams Product Freshly Freshly'L- After storage for Raw' COOki; processed 2 months 4 months %-months mg. 8* mg. Rt mg. %R* mg. %R* mg. %R* i wet 7* t 7’ Frozen n basis 7.7 5.0 65 5.6 73 4.2! 55 3.3 43 3.1 41 cartons any - basis 58 18 33 26 45 127 21 13 22 13 22 113313 wet 4'5 407 3.0 2.7 2.4 -T--" T" ~ Canned-igrs basis 7.7 5.0 65 4.7 61 3.1. 40 2.6 34 2.3 30 . d . V. ja;: beige 58 19 33 14 24 9 15 9 15 5 14 Dehy- as b:::s 7.7 5.0 65 #4 4* at 4* 4* at *4 *4 drated Sizigd biggs 58 18 32 *4 it 4* at #t as 4* *4 t %R.- % retention. ** No ascorbic acid. -35- Table 9. Effect of freezing, canning, dehydrating and salting on ascorbic acid content of Landreth Stringless Green Pod Snap beans. Ascorbic acid per 100 grams Freshly ;Freshly I After storage for Product 1 Raw cooked Aprocessed 2 months 4 months* 6% months mg: %R* mg. %thI mg. %R ' mg. %R mg. %R in b:::s 25.5 23.4 92 24.5 96 18.6 73. 18.2 71 17.9 70 Frozen cart°°3 bzgis 282 332 118 272 96 198 70 215 76 190 67 112318 ‘wet 9.0 11.3 10.0 ’ 7.7‘ 8.6 beifié 29.5 14.4 48 9.8 33 9.2 31 9.- 32 9.8 33 Canned in jars basis 29.5 12.1 41 10.5 36 9.5 32 8.7 29 9,3 32 1a:: biggs 241 233 97 256 106 200 83 184 76 192 80 Dehy as 52:33 21.7 18.3 84 4* *4 4* *t *4 ** as 4* drated 3:218d bggis 229 396 172 ** at as we 4* at 4* 4* 113318 wet 15'2 3'0 > 2-8 2.7 2.7 Dny_ beifis 27.5 18.9 69 2.5 9 2.7 10 2.6 9 2.5 9 8°1t°d 13:: basis 27.5 17.6 64 27 9 2.7 10 2.4 9 2.6 9 jaig biggs 261 283 108 35 13 36 13 31 12 34 13 li::id wet 21.2 2.8 2.5 2.6 2.5 beiflg 25.6 23.5 92 3.0 12 3.3 13 2.6 10 2.6 10 Brined in jars baSiS 25.6 23.1 91 2.9 11 2.9 11 206 10 2.6 10 #39:: bzzgs 282 332 118 40 14 41 15 37 13 39 14 * %R.- % retention. ** No ascorbic acid. -35- Freshly frozen beans retained 96 percent of the original ascorbic acid content on wet basis, while freshly cooked beans retained 92 per- cent which was very close to the former. Frozen beans were blanched before freezing. Freshly cooked beans were cooked in water. The results indicated the similar effects on ascorbic acid retention due to freezing process and cooking. Frozen cherries and green beans suffered a further loss of 23 and 29 percent of ascorbic acid respectively after half year of storage. Effect pf Canning The cherries lost 39 percent of their original ascorbic acid on wet basis while the beans lost 44 percent during canning. The freshly cooked cherries retained 65 percent of the original ascorbic acid and the freshly canned retained 61 percent. The retention of freshly cooked beans was 41 percent and that of freshly processed beans was 36 percent. The additional handling in canning in both cases did not cause any marked loss. Cherries lost another 21 percent of ascorbic acid during the first two months' storage and 10 percent till the end of the storage. Two months' storage caused 4 percent loss of ascorbic acid in beans and the later additional four months' storage had no effect on the ascorbic acid content of the canned beans. It showed that the main loss of ascorbic acid during storage of canned products occurred in the first two months. Effect pf Drying Dehydration of both cherries and beans resulted in total destruction of ascorbié acid. One important factor that caused this total loss is -37- due to the long exposure of material in the air at high temperature during dehydration. EEEEEE.2£ Saltipg Freshly brined and dry-salted beans retained relatively little amount of the original ascorbic acid. The retention of ascorbic acid in freshly brined beans was 11 percent, and that of freshly dry-salted beans 9 percent of the original content. Fermentation and repacking process caused a great loss of ascorbic acid in beans. Ascorbic Acid in Liquid Portions Tables 8 and 9 show that liquid contents of the processed products contained a considerable portion of the ascorbic acid present. The ascorbic acid content tended to become equalized in the solid and liquid parts with time in storage. The ascorbic acid diffused gradually from the fruit and vegetable to the surrounding liquid during storage. The average percentage present in the liquid of the products at the end of storage was around 50 percent in wet basis. -38- SUMMARY AND CONCLUSIONS Landreth Stringless Green Pod beans were preserved by home methods of canning, freezing, dehydrating and salting while Montmorenoy cherries ‘were preserved by canning, freezing and dehydrating. Palatability tests, ascorbic acid determinations and objective color measurements were made on samples at different stages: 1) raw, 2) freshly cooked, 3) freshly processed and 4) after storage for two, four and six and a half months. The results of the tests permit the following conclusions: 1. 2. 3. 5. Freezing gave the best results for palatability factors and ascorbic acid values of both cherries and beans. Canning was rated the second best methodoin ascorbic acid retention and palatability scores. Dehydration of both cherries and green beans resulted in complete destruction of ascorbic acid, and unfavorable changes of color, flavor and texture. Both brined and salted beans were poor sources of ascorbic acid, but good in texture and fair in other palatability scores. The palatability of processed food declined with storage. Dehydrated, brined and dry-salted beans became unaccept- able towards the end of the six and a half months of storage. All other samples were satisfactory throughout the experiment. -39- 6. The color qualities varied with different processing methods and declined with storage. Dehydrated samples had the low- est figures for value (darkest) and chroma (loss of color). Frozen samples had the highest readings for hue (most green of beans and most red of cherries) and chroma (color reten- tion) and had high readings for value next to the freshly cooked. Samples processed in other ways had readings in be- tween for these three qualities. -40.. LIST OF REFERENCES Alderman, D. C. and B. Newcombe. Dehydration Of Montmorency cherries. 1945 Mich..Agr. Exp. Sta. Quar. Bull. 2§_#2. Bedford, C. L. and M. A. McGregor. Effect of canning on the ascorbic 1948 acid and thiamine in vegetables. J. Am. Dietetic Assoc. 33; 866-869. Blum, H. B. and F. W} Fabian. The influence of salting upon.vitamins 1942 A and c in vegetables. Fruit Products J. _2_2_ #9: 273-275, 283. Bureau of Home Economics. Community food preservation centers. U. S. 1941 D. A. Miscellaneous Publication #472. Bureau of Human.Nutrition and Home Economics. Cooking dehydrated 1944 vegetables. U. S. D. A. AIS-8. . Drying foods for victory meals. U. S. D. A. Far- 1942 mers' Bull. #1918. . Home canning of fruits and vegetables. U. S. D. A. 1947 AIS-64. . Home freezing of fruits and vegetables. U. S. D. A. 1946 AIS-48. o Oven drying. U0 3. Do A. AVE-59. Crafts, A. S. Cellular changes in certain fruits and vegetables during 1944 blanching and dehydration. Food Research 9; 442-452. Cruess, W3 V. The nutritive value of dried fruits and vegetable. 1942 Fruit Products J. 2_2#3: 3-6, 69-72, 91; #4: 111-114; #5: 136-137; #6: 171-174; #8: 181. , A. Afifi and I. G. A. Glazewsky. Experiments on frozen 1948 fruits. Frozen Food Ind. 4'#l: 6-11. Eheart, M. S. and M. L. Sholes. Effects of methods of blanching, stor- 1945 age, and cooking on calcium, phosphorus and ascorbic acid contents of dehydrated green beans. Food Research 12; 342- 350. Etchells, J. L. Preservation of vegetables by salting or brining. U. S. 1943 D. A. Farmers' Bull. #1932. , and I. D. Jones. Commercial brined preservation of vegetables. "'I9"'"43" Fruit Products J. §_2_#8: 242-246, 251-253. Fabian, F. 1. and H. B. Blum. Preserving vegetables by salting. 1943 Fruit Products J. 2§.#8: 228-236. Farrell, K. T. and C. R. Fellers. 'Vitamin content of green snap 1942 beans. Influence of freezing, canning and dehydration on the content of thiamin, riboflavin and ascorbic acid. Food Research Z: 171. Feaster, J. F., M; D. Tompkins and W. E. Pearce. Effect of storage 1949 on.vitamins and quality in canned foods. Food research 14: 25-390 Fitzgerald, G. A. and C. R. Fellers. Carotene and ascorbic acid 1938 content of fresh market and commercially frozen fruits and vegetables. Food Research 3; 109-120. Georgia Home Food Preservation Committee. Progress report and recomp 1946 mendations. Ga. Agr. Coll. Ext. Bull. #525: 1—39. Guerrant, N. B., M. G. Vavich and O. B. Fardig. The nutritive value 1946 of canned foods. Changes in the vitamin content of foods during canning. J. Nutrition 32} 435-458. Good, Nary K. A study of the prevention of browning in frozen sliced 1948 apples for use in pie. Unpublished M. S. Thesis, Mich. State College, 23-26. Griswold, Ruth M. Factors influencing the quality of home canned 1944 Nontmorency cherries. Mich. St. Agr. Exp. Sta. Tech. Bull. #194. Gruetzmacher, L. C., T. Onsdorff and M. C. mask. Canning for home 1948 food preservation. Oregon Agr. Exp. Ext. Bull. =#689. IHummel, M. E. Factors in processing which affect the ascorbic acid 1942 content of fruits and vegetables. Fruit Products J. 21' #93 2730 (Tenkins, R. R., D. K. Tressler and G. A. Fitzgerald. Vitamin C in 1938 vegetables. Storage temperature for frosted vegetables. Ice and Cold Storage 31: 100-101. PCirk, M. M. and D. K. Tressler. Ascorbic acid content of pigmented 1941 fruits, vegetables and their juices. Food Research 6: 395-409. Iuoeffler, H; J. and J. D. Ponting. Ascorbic acid - rapid determina- 1942 tion in fresh, frozen or dehydrated fruits and vegetables. Ind. Engr. Chem. Anal. Ed. 14; 846-849. -42- Loomis, L. C. The preservation of food. U. S. D. A. Report #1862: 1863 470-494. Iueck, R. H. and R.‘W. Pilcher. Canning fruit juice: Technical 1941 aspects. Ind. Engr. Chem. 33; 292-300. Imyfield, H. L. anle. E. Richardson. The vitamin content of green 1939 string beans when cooked or canned and stored. Mont. Agr. EXP. Sta. 81.111. #3730 McIntosh, J. The effect of preparation for freezing, freezing storage 1944 and cooking on the vitamin content of vegetables. Fruit Products J. 23 #r: 143-145, 149. Michigan State College Extension Service. Preservation of fruits and 1948 vegetables by freezing. Mich. St. 0011. Ext. Bull.-#208. Peterson, C. S., G. L. mack and W} L. Athawes. Vitamin C content of 1939 sauerkraut. Food Research 4: 31-45. Shmidt, A. A. Stability of vitamin C during commercial canning of 1941 fruits and vegetables. Chem. Abstracts 36: 2943. (Proc. Sci. Inst. Vitamin Research U. S. S. R.j§?#l: 234-244). Sugihara, J. and'W2 V. Cruess. Effect of blanching on the dehydra- 1941 tion rate of vegetables. Fruit Products J. §l_#4: 104-106; #5 3 159‘1400 Weigand, E. H., E. M. Litwiller and M. B. Hatch. Dehydration of cher- 1945 rise and small fruits. Fruit Products J. 2§f#l: 9-14, 23. Winter, J. D. and A. Hustrulid. Freezing foods for home use. Minn. 1945 Agr. Ext. Bull. #244. 'Woodroof, J. G. and E. Shelor. Effect of storage temperature on frozen 1948 foods. Refrig. Engr. 56} 514-517, 550. -43- APPENDIX Table 10. Percent Total Solids of Green Beans. mien-1mm r . . flit! l l I I I i I (liquid 1 1.. ~45- §Treatment Raw ‘ Freshly iFreshly l Stored LII i cooked processed 2 months—i4 months !6 months I' a % Dry- “drained 12.23 10.84 10.94 10.61 10.93 10.38 salted: ; liquid I —-- 2.51 5.18 5.44 6.42 5.75 drained E 9.08 15.05 9.43 9.34 9.31 8.65 Brined ‘ liquid --- 2.58 5.31 5.23 5.27 5.00 . Frozen 9.08. 15.05 9.02 9.38 8.45 9.40 drained 9.46 8.64 16.57 16.65 15.67 14.87 Dried iliqu1d --" 2065 6.64 6.68 6. 74 6.58 'drained 12. 23 10.84 7.68 7.82 7.47 7.72 , Canned . liquid --- 2.43 2.86 3.32 2.96 3.17. Table 11. Percent Total Solids of Red Cherries. rTreatment Raw Freshly Freshly Stored ' cooked processed 2 months 4 months 6 mont m i in i 1 §Frozen 13.19; 27.78 21.30 35.29 i 25.18 E 23.62 2 L t 4 idrained 13.19: 27.78 35.83 21.93 38.42 34.52 €Dried I Iliquid --- 9 26.76 40.62 39.84 41.27 38.71 ‘drained ;l3.19. 27.78 36.22 35.49 31.17 30.69 :Canned! s --- 26.76 27.85 30.86 29.75 29.52: Wu. MICHI AN STATE UNIVERSITY LIBRARIES G l lllll l 3 1293 lllllllli 3145 8809 u; r