6000-L180 TEXAS AERICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS ij-BULLETIN NO. 483 DECEMBER, 1933 DIVISION OF HORTICULTURE Improved Methods 0f Utiliiing T the Magnolia Fig T LTBRARY Agncultural 8- anical College o! Texas - WW 4| “EENH. H ‘V Q * AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. 0. WALTON, President STATION STAFFT Administration : A. B. Conner, M. S., Director R. E. Karper, M. S., Vice-Director Clarice Mixson, B. A., Secretary M. P. Holleman, Chief Clerk J. K. Francklow, Asst. Chief Clerk Chester Higgs, Executive Assistant Howard Berry, B. S., Technical Asst. Chemistry: G. S. Fraps, Ph. D., Chief; State Chemist S. E. Asbury, M. S., Chemist J. F. Fudge, Ph. D., Chemist E. C. Carlyle, M. S., Asst. Chemist T. L. Ogier, B. S., Asst. Chemist A. J. Sterges, M. S., Asst. Chemist Ray Treichler, M. S., Asst. Chemist W. H. Walker, Asst. Chemist Velma Graham, Asst. Chemist Jeanne F. DeMottier, Asst. Chemist R. L. Schwartz, B. S., Asst. Chemist C. M. Founders, B. S., Asst. Chemist Horticulture: S. H. Yarnell, Sc. D., Chief Range Animal Husbandry: J. M. Jones, A. M.. Chief B. L. Warwick, Ph. D., Breeding Investiga. S. P. Davis, Wool Grader J. H. Jones, B. S., Animal Husb. Entomology: F. L. Thomas, Ph. D., Chief; State Entomologist H. J. Reinhard, B. S., Entomologist R. K. Fletcher, Ph. D., Entomologist W. L. Owen, Jr., M. S., Entomologist J. N. Roney, M. S., Entomologist J. C. Gaines, Jr., M. S., Entomologist S. E. Jones, M. S., Entomologist F. F. Bibby, B. S., Entomologist "E. W. Dunnam, Ph. D., Entomologist "R. W. Moreland, B. S., Asst. Entomologist C. E. Heard, B. S.. Chief Inspector Veterinary Science: ‘M. Francis, D. V. M., Chief H. Schmidt, D. V. M., Veterinarian “F. P. Mathews, D.V.M., M.S J. B. Mims, D. V. M., Asst. Veterinarian Plant Pathology and Physiology: J. J. Taubenhaus, Ph. D., Chief W. N. Ezekiel, Ph. D., Plant Pathologist Farm and Ranch Economics: L. P. Gabbard, M. S., Chief W. E. Paulson, Ph. D., Marketing C. A. Bonnen, M. S., Farm Management I"W. R. Nisbet, B. S., Ranch Management "A. C. Magee, M. S., Ranch Management Rural Home Research: Jessie Whitacre, Ph. D., Chief Mary Anna Grimes, M. S., Textiles Sylvia Cover, Ph.D., Foods Soil Survey: "W. T. Carter, B. S., Chief E. H. Templin, B. S., Soil Surveyor A. H. Bean, B. S., Soil Surveyor R. M. Marshall, B. S., Soil Surveyor Botany: V. L. Cory, M. S., Acting Chief Swine Husbandry: Fred Hale, M. S.L Chief Dairy Husbandry: O. C. Copeland, M. S., Dairy Husbandman Poultry Husbandry: R. M. Sherwood, M. S., Chief J. R. Couch, B.S., Asst. Poultry Husbandman Agricultural Engineering: H. P. Smith, M. S., Chief Main Station Farm: G. T. McNess, Superintendent Apiculture (San Antonio): H. B. Parks, B. S., Chief A. H. Alex, B. S., Queen Feed Control Service: F. D. Fuller, M. S., Chief Breeder C. J. Burgin, B. S., Foulbrood Inspector James Sullivan, Asst. Chief Agflillflmyl S. D. Pearce, Secretary E. B. Reynolds, Ph. D., Chief J. H. Rogers, Feed Inspector R. E. Karper, M. S., Agronomist K. L. Kirkland, B. S., Feed Inspector P. C. Mangelsdorf, Sc. D., Agronomist S. D. Reynolds, Jr., Feed Inspector D. T. Killough, M. S., Agronomist P. A. Moore, Feed Inspector‘ Publications: _ E. J. Wilson, B. S., Feed Inspector A. D. Jackson, Chief H. G. Wickes, D. V. M., Feed Inspector SUBSTATIONS No. 1, Beeville, Bee County: R. A. Hall, B. S., Superintendent N0. 2, Lindale, Smith County: P. R. Johnson, M. S., Superintendent No. 9, Balmorhea, Reeves County: J. J. Bayles, B. S., Superintendent No. 10, College Station, Brazos County: R. M. Sherwood, ,M. S., In Charge "B. H. Hendrickson, B. S., Sci. in Soil Erosion L. J. McCall, Farm Superintendent "R. W. Baird, M. S., Assoc. Agr. Engineer No. 3, Angleton, Brazoria County: R. H. Stansel, M. S., Superintendent H. M. Reed, M. S., Horticulturist No. 4, Beaumont, Jefferson County: R. H. Wyche, B. S., Superintendent "H. M. Beachell, B. S., Junior Agronomist No. 5, Temple, Bell County- Henry Dunlavy, M. S., Superintendent C. H. Rogers, Ph. D., Plant Pathologist H. E. Rea, B. S., Agronomist S. E. Wolff, M. S., Botanist E. B. Deeter. B. S., Soil Erosion No. 11, Nacogdoches, Nacogdoches County: H. F. Morris, M. S., Superintendent "No. 12, Chillicothe, Hardeman County: "J. R. Quinby, B. S., Superintendent "J. C. Stephens, M. A., Asst. Agronomist No. 14, Sonora, Sutton-Edwards Counties: W. H. Dameron, B. S., Superintendent I. B. Boughton, D. V. M., Veterinarian W. T. Hardy, D. V. M., Veterinarian O. L. Carpenter, Shepherd "O. G. Babcock, B. S., Asst. Entomologist No. 15, Weslaco, Hidalgo County: W. H. Friend, B. S., Superintendent P. L. Hopkins, B. S., Junior Civil Engineer S. W. Clark, B. S., Entomologist No. 6, Denton, Denton County: P. B. Dunkle, B. S., Superintendent "I. M. Atkins, B. S., Junior Agronomist No. 7, Spur, Dickens County: R. E. Dickson, B. S., Superintendent B. C. Langley, M. S., Agronomist No. 8, Lubbock, Lubbock County: D. L. Jones, Superintendent Frank Gaines, irrig. and Forest Nurs. W. J. Bach, M. S., Plant Pathologist J. F. Wood, B. S., Horticulturist No. 16, Iowa Park. Wichita County: C. H. McDowell. B. S., Superintendent L. E. Brooks, B. S., Horticulturist No. 19, Winterhaven. Dimmit County: E. Mortensen, B. S., Superintendent "L. R. Hawthorn. M. S.. Horticulturist Members of Teaching Staff Carrying Cooperative Projects on the Station: G. W. Adriance, Ph. D., Horticulture S. W. Bilsing, Ph. D., Entomology D. Scoates, A. E., Agricultural Engineering A. K. Mackev. M. S.. Animal Husbandry R. G. Reeves. Ph. D., Biology "‘Dean, School of Veterinary Medicine. J. S. Mogford, M. S., Agronomy F. R. Brison, M. S., Horticulture W. R. Horlacher, Ph. D., Genetics J. H. Knox. M. S., Animal Husbandry A. L. Darnell, M. A., Dairy Husbandry TAs of December" l. 1933 "In cooperation with U. S. Department of Agriculture. $In cooperation with Texas Extension Service. ., Veterinarian a-u I n"... A" - Steps in the prevailing commercial method of processing Magnolia figs have been carefully examined in the laboratory with the view of possible improvement. A method of canning in light sirup adapted for use with the Magnolia fig is presented in detail. Forty per cent glucose to sixty per cent cane sugar is recommended as the most satisfactory ratio for candying figs. Sulfur dioxide at a concentration of 1000 parts per million was found to keep figs at the hard-ripe stage for nine months. Higher concentrations kept such figs for over a year. The effect of washing to remove the sulfur dioxide is discussed. CONTENTS Page Fig Preserves ....................................... -. Present Methods Effect of the Concentration of Lye on Its Peeling Efficiency .......... l. 6 _ Effect of Acid Dip on Lye-Peeled Figs ' ____ 1 -- A Modified Dip for Fig Preserves“--- Canning Magnolia Figs in Light Sirup - Preliminary Tests ................ -- 9 A_ Effect of Increased Acidity on Flavor.___ l10f Removing the Roughness from the Skin .......................................... --10 Effect of Blanching on Texture .............................................................. _.12 Effect of Maturity _____ -_12 T._ Exhausting . - 13 ii Cooking 13 _‘ Cooling .................... . . . . . . . . c 1s Consumers’ Reaction 13 Recommended Procedure for Canning Figs in Light Sirup ................. __14 Candied Figs ~~~~ -- __ 14 Addition of Glucose .- _..14 I Modified Methods _ 15 Use of Acid 16 Use of Pectin Dip A16 Preservation of Magnolia Figs in Sulfurous Acid .17 Effect of Concentration of Sulfurous Acid on Time of Keeping ..... -.17 Method of Removal of Sulfur Dioxide 18 __ Products from Figs Stored in Sulfurous Acid _____________________________________ n19 \ Acknowledgments 19 Summary 19 Literature Cited 20 _iii $1.; _..-“~l " BULLETIN NO. 488 DECEMBER, 1933 IMPROVED‘ METHODS OF UTILIZING THE MAGNOLIA FIG H. M. REED Since its beginning the Texas fig industry has been concerned chiefly with the manufacture and marketing of fig preserves. When fig pro‘- duction was still comparatively small the preserving plants had no difficulty in finding sufficient markets for their products, so that the problem of what to-do with surplus figs was of no particular importance. As the bearing acreage of Magnolia figs increased, overproduction occurred with serious consequences to the industry (8). The results of over- production were felt by the growers in decreased returns for their figs and by the preserving plants in the necessity for widened markets and in the loss of figs due to spoilage before they could be preserved. It is probable that the problems concerned with a surplus can be greatly relieved by manufacturing a greater variety of fig products. This should make possible the utilization of figs that would normally be wasted under p the present system of manufacture. The investigations which are reported in this publication were made to assist in solving the problems of surplus. Throughout _this publication the terms excellent, good, fair, and poor are used to describe the quality of the appearance, texture, and flavor of the products under experiment. When the products were judged for appearance, the color, uniformity of size, and freedom from blemishes were taken into account. The canned fruit was considered to have a good texture when it was tender but firm, as judged by cutting with a spoon, or by eating it. The more closely the flavor of the product resembled that of the fruit from which it was made, the better it was considered to be. Since the terms used to describe the quality of the products do not represent exact quantitative measurements, they are chiefly of value when used in a comparative sense. Repeated observations by as many ’ as nine individuals have been relied upon to make the comparative results reliable. FIG PRESERVES Present Methods The method of making Magnolia fig preserves in Texas has been prac- tically the same from the time the industry began up to the present time. The procedure, with a few variations by individual preserving * plants, is as follows: The figs are brought in from the orchards at the hard-ripe stage of maturity. At this degree of ripeness, they are very . firm and can be put through the preserving process with little trouble from cooking to pieces. The figs are peeled by being passed through a iiboiling solution of commercial sodium hydroxide of approximately 2 per cent concentration. This form of lye is most commonly used in the canning industry for peeling fruits. u 6 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION They are then rinsed in fresh water, and the stem and any peeling which remains are trimmed from the fruit by hand. About one-half as much cane sugar as the weight of peeled figs is'added to some water in large open kettles. This mixture is brought to a boil with constant stirring until a sirup of 30-38° Baume' is obtained. When the fruit is inclined to be soft it is added to a heavier, sirup than when the fruit is firm. After the prepared figs have been added’ to the boiling sirup, boiling is continued until they become translucent and the sirup reaches the desired density. The heavy preserves are finished in sirup of about 24° Baume’ and the breakfast preserves in sirup of about 18° Baume’. The Baume' determinations are made by means of a hydrometer at frequent intervals during the cooking process while the sirup is boiling hot. The time required for cooking is 40 minutes to 2 hours. When cooking is completed, the figs are cooled by circulating water through the jackets of the kettles, and Where possible they are allowed a to stand in the kettles for several hours to permit them to take up the sirup and become plump. Finally they are packed by hand in tin or glass containers and exhausted* until the temperature of the figs reaches 140° to 160° F. The containers are sealed and then sterilized at 190° to 212° F. for 15 to 50 minutes, the length of time depending upon the type and size of the container. The sterilized containers are cooled in water to approximately 120° F. Heating and cooling of the glass con- tainers are done gradually to prevent them from breaking. Effect of the Concentration of Lye on Its Peeling Efficiency Tests were made to determine the effect of the concentration of lye on its peeling efficiency with Magnolia figs. Only hard-ripe figs were used and these were graded for uniformity of size and quality. They were divided into lots of 30 to 40 figs, placed in a wire basket, and dipped into 2, 5, 10, 15, and 25 per cent boiling commercial-lye solutions for different intervals of time. After the dipping treatment, the figs were rinsed in fresh water and examined immediately. The examination was first made independently by two observers on the basis of individual figs in each lot. Final observations were recorded by agreement of the two observers after examining each lot a second time. When the dipping solution removed practically all of the skin without eating into the flesh, the treatment was considered “very good.” When less of the skin was removed, the results were recorded as “good,” “not quite enough,” or “not enough,” depending upon the amount of skin removed. When pitting of the flesh occurred the results were recorded as “very slightly too much,” “slightly too much,” or “too much,” depending upon the severity of the treatment. *“Exhausting” is the term used in canning to express the action of heating the container and its contents before sealing to provide a. partial vacuum in the container after it is ~ sealed, sterilized, and cooled. \ . ‘JAHZQL i ' p. .. .'.'.‘- . ~, , s ~_- ‘l1 _. - _ “w, ‘H, I 7-» i.‘ = ., ‘i, hQ - -' ~ >~,... w‘ ,=Y~._..-,. ;,~-;" ., IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 7 The tests with 2 and 5 per cent lye solutions were repeated the next season and an additional test was made with a 1 per cent lye solution. The results as given in Table 1 show that a slightly longer dip was Table 1. Effect of concentration of lye and of time on peeling efficiency Year of test Per cent lye Tlme dlpped Observations seconds l 1933 1 30 not quite enough 1933 1 40 very good 1933 1 50 very slightly too much 1933 1 60 slightly too much 1932 2 30 not quite enough 1932 2 35 very good 1932 2 4O very good 1932 2 45 slightly too much 1932 2 5O too much 1933 2 3O very good 1933 2 35 very good 1933 2 40 very slightly too much 1933 2 45 slightly too much 1932 5 20 not quite enough 1932 5 25 very good 1932 5 30 very slightly too much 19312 5 35 too much 1933 5 2O very good 1933 5 25 very slightly too much 1933 5 3O slightly too much 1933 5 35 too much 1932 10 15 not enough 1932 1O 20 very good 1932 l0 25 good 1932 10 30 too much 1932 15 10 not quite enough 1932 15 15 very good 1932 15 2O too much 1932 2O 10 not quite enough 1932 20 15 very good 1932 20 20 slightly too much 1932 25 10 not quite enough 1932 25 15 too much required with the 2 and 5 per cent solutions in 1932 than with the same lye concentrations in 1933. They also show that the 1 and 2 per cent solu- tions with the proper length of dip are just as effective in peeling the figs as the higher concentrations, and have the additional advantage of providing a longer interval between the period that gives good results and the period that is too severe. Effect of Acid Dip on Lye-Peeled Figs At the stage of ripeness used for preserving, the Magnolia fig has an opening at the blossom end that can very easily permit the entrance of the lye solution into its interior during the scalding process. While the rinsing process probably removes most of the lye from the figs, there is a possibility that a small amount may remain in the fruit and affect the quality of the preserves. 8 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION To test this possibility, Magnolia figs at the hard-ripe stage were graded for uniformity of quality and divided into two portions containing enough figs to make twelve cans of preserves from each portion. One lot was made into heavy preserves by the regular process. The second lot was scalded in the 2 per cent lye solution, rinsed in fresh water, and then dipped in a 0.5 per cent hydrochloric acid solution, and finally rinsed again in fresh water. The figs were then trimmed and preserved as with the first lot. It was found that the acid dip made the figs more difficult to trim by causing the remaining skin around the stem end of the fruit to adhere more tightly. For this reason it was more practical to dip the figs in the acid solution after instead of before trimming them. Observations were made by two observers immediately after the figs had been preserved, and on the canned samples after about two weeks. A third observation was made on the samples by one individual after they had been canned about 7 months. The canning tests were repeated the following season, and at this time samples of figs were withdrawn from the regular lye-peeled figs and from those which had been lye-peeled and acid-dipped. Colorimetric pH determinations made with Brom phenol blue indicator on the juice expressed from the sample, and on the juice from fresh untreated figs showed that the pH of the juice from the regularly lye-peeled figs was very slightly higher. The remaining figs from these tests were made into heavy- sirup preserves. Examination of these preserves was made by four indi- viduals two months after canning. The pH on the sirup from the canned preserves which had been made from the acid-dipped figs was very slightly lower than on the sirup from the canned preserves made by the regular method. In all cases, the preserves made from the acid-dipped figs were slightly brighter in appearance and of slightly better taste than those that were preserved by the regular method. A Modified Dip for Fig Preserves The process now used in making fig preserves was modified byfirst removing the stems of the figs and then dipping them in a boiling 2 per cent sodium bicarbonate (baking soda) solution for 30 seconds and rinsing in water. After this treatment the regular preserving process was fol- lowed to make twelve cans of preserves. l Examinations were made by two observers immediately after preserv- ing and again on the canned samples about one month after preserving. The preserves were found to be as good in texture and flavor as those made from lye-peeled figs, although they were less attractive in appearance in that they were darker in color and the figs that had skin blemishes such as leaf scars and rust spots retained them after they were pre- served. .ll|<‘ MM...;.».~.~a».1-,.;\.s;...;;t.za.$-.. .. IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 9 A similar test was conducted one year later. The figs used were of better quality and the resulting preserves were more attractive in appear- ance than those of the previous year, but were darker in color than the preserves which had been made from lye-peeled figs. The advantage of the modified method is that the preserves are cheaper to produce because hand trimming is simplified to merely removing the stem; there is less actual loss in weight of fruit; and, since the sodium bicarbonate removes only the outer portion of the skin, slightly riper figs can be used Without danger of breaking up in the preserving process. CANNING MAGNOLIA FIGS IN LIGHT SIRUP Some varieties of figs, as, for example, the Kadota, are canned in a light sirup‘ without being peeled (4). In general, the method is to give the figs a short blanch in hot water or steam and then place them in cans. The fruit is covered with sirup and the cans are sealed and sterilized. The actual cooking of the fruit occurs during sterilization. This method has the advantages of a lower cost of production than canning in heavy sirup and of providing a product that more nearly resembles the fresh fig in flavor. A series of tests was made to establish a method for making a similar product from the Magnolia fig. Preliminary Tests A study of the suitability of the Magnolia to Kadota-fig-canning methods included the following: to determine (1) the effect of blanching, (2) the most pleasing degree of sweetness, and (3) the most effective length of sterilization. The figs used in the tests were at the hard- ripe stage of maturity. Observations were made a few weeks after canning by seven people. About six months later samples were again examined by a single observer to note any change which might have occurred during that time. From a study of the results, it was found that water was more effective than steam as a blanching medium for removingithe green taste and improving the texture. Figs canned in 50° and in 60° Brix (27.3° and 32.5° Baume’) sirup had the most pleasing degree of sweetness for bring- ing out the fig flavor. When these canned samples were opened and examined, the sirup had become diluted by the juice in the figs to 21°- 31° Brix (11°-17° Baume’). The relation between degrees Brix and degrees Baume’ is shown in Table 2. On the average, for figs at the hard-ripe stage of maturity, a two- hour cook in sealed No. 1 tall cans at boiling-water temperature was the most effective. Less than two-hour cooks left a green taste in the figs and they were usually too hard and tough in texture. Magnolia figs packed in this Way" have a rough skin, which becomes more apparent after they have been canned for several months. They have a rather poor texture, and lack a pronounced fig flavor. V10 BULLETIN NO. 483 TEXAS AGRICULTURAL. EXPERIMENT STATION Table 2. Relation between degrees Brix and degrees Baume’* Degrees Brix Degrees Baume' Degrees Brix Degrees Baume’ 20 11.10 50 27.28 25 13.84 55 29.90 30 16.57 60 32.49 35 19.28 65 35.04 40 21.97 70 37.56 45 24.63 75 40.03 *From official methods of analysis of the Association 0f Official Agricultural Chemists, Washington, D. C Effect 0f Increased Acidity on Flavor Many fruits owe their pleasing flavor to a natural acidity. Among the fruits, figs are relatively lOW in acid content (2). To test the effect of increasing the acidity of canned Magnolia figs seven No. 10 cans of fruit which had previously been canned with Water were drained and the juice made up to a 50° Brix (27.3° Baume’) sirup with cane sugar. The sirup was divided into three portions. To the first 0.2 per cent citric acid was added on the basis of sirup solids, to the second 0.25 per cent, and to the third 0.5 per cent citric acid was added. The drained figs were then re-canned in No. 1 tall cans with the use of acidi- fied sirups. The cans were exhausted 5 minutes in steam, sealed, and sterilized 20 minutes at boiling-water temperature. From numerous observations made on these samples by different indi- viduals it was noted that the addition of citric acid materially improves the flavor, and that while 0.25 per cent acid did not seem to be sufficient, the figs canned with the 0.5 per cent citric acid in the sirup were too acid in flavor. A similar test using 0.35 per cent citric acid based on the weight of sirup solids gave a very effective acidity from the standpoint of flavor. Additional tests in which fresh figs were canned with 0.35 per cent citric acid in the sirup and with no acid in the sirup again pointed out the improvement in flavor due to the presence of the acid. The method of basing the percentage of acid on the weight of sugar was used because in the preserving plants the weight of sugar used to make up the sirup is definitely known, whereas the amount of water used to make the sirup and the weight of figs used per batch are only approximately known. - Removing the Roughness from the Skin It was found that by using a modification of the lye-scalding process, the roughness of the skin of the Magnolia figs can be removed without entirely removing the skin. In contrast to the action of sodium hydroxide in the lye-peeling process, which separates the entire skin of the fruit from the flesh, the modified method removed enough of the outside layer of the skin to eliminate the objectionable roughness. IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 11 The figs were picked and graded for two stages of maturity, hard-ripe and ripe. The latter stage represents about one day more of tree ripen- ing than the hard-ripe figs. During this time the fig becomes less green in color and less firm in texture and is at the stage of ripeness most generally preferred for eating in the fresh state. By means of a wire basket small lots of the figs were dipped into boiling solutions of 2 per cent sodium hydroxide, 2 per cent sodium bi- carbonate, and 2 per cent potassium carbonate for varying periods of time and the effect on the skin noted immediately after dipping and rinsing the samples in fresh water. Similar tests were made with 10 per cent solutions of the same compounds at room temperature (80° F.). Examination of the samples was made by two independent observers judging the individual figs in each lot and reaching a final conclusion by agreement after a second observation. In cases where there was any doubt as to the effectiveness of the dip, testing was done by rubbing the figs across the lips and noting whether they felt smooth or rough. The results of the dipping tests are presented in Table 3. From the standpoint of effectiveness and economy the boiling 2 per cent sodium bicarbonate solution proved to be very satisfactory. The hard- Table 3. Effect of various solutions on removing roughness of skin Hard-ripe figs Ripe figs . . . "a E ‘*5 E Dipping solution* Q g g . m Q ,1 _ g 2Q 8 Observation E L; 8 Observation Q 3 Q 3 2% Sodium hydroxide l 2 I effective 5 removed all the skin 2% Sodium hydroxide .4 I removed all the skin 10 removed all the skin 2% Sodium hydroxide l 5 l removed all the skin 3O removed all the skin 2% Sodium bicarbonate 5 no effect 15 effective 2% Sodium bicarbonate 10 no effect 30 removed all the skin 2% Sodium bicarbonate 15 no effect 45 removed all the skin 2% Sodium bicarbonate l 25 I effective 1 2% Potassium carbonate I 5 no effect 15 effective 2% Potassium carbonate . 15 no effect 30 removed all the skin 2% Potassium carbonate l 20 effective 45 removed all the skin 2% Potassium carbonate , 25 removed all the skin 10% Sodium hydroxide 30 I removed all the skin 30 effective 10% Sodium hydroxide 45 pitting of flesh 45 removed all the skin 10% Sodium hydroxide 60 pitting of flesh 6O removed all the skin 10% Sodium bicarbonate 30 no effect 3O effective 10% Sodium bicarbonate 45 no effect 45 removed all the skin 10% Sodium bicarbonate 80 no effect I 80 removed all the skin 10% Potassium carbonate 30 effective 30 removed all the skin 10% Potassium carbonate 45 removed all the skin 45 removed all the skin 10% Potassium carbonate 90 removed all the skin 90 removed all the skin '2% Solutions at boiling temperature, 10% solutions at 80° F. ripe figs required a longer dipping time than the ripe figs. In general, a dip of 15 to 30 seconds in a boiling 2 per cent sodium bicarbonate solution, the length of time depending upon the maturity of the figs, was effective in removing the roughness of the skin. 12- BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION Effect of Blanching on Texture As has already been pointed out, Water seemed t0 be more efficient than steam as a blanching medium in the preliminary tests. A combina- tion of the sodium bicarbonate dip and the boiling=water blanches were tried for different lengths of time to determine a method for producing canned figs of good texture with hard-ripe and ripe fruit. From the standpoint of a canned fruit the texture of the figs was considered to be poor before the treatments because they were too firm and tough. After the figs had been dipped in the boiling bicarbonate solution for the required length of time, they were rinsed and placed in the boiling water for 1, 2, 3, 4, and 5-minute periods. Examination of the samples was made immediately after blanching by three observers in the same manner as described in the experiments to » remove the roughness of the skin. The results of these tests are given in Table 4. After the samples had been examined they were placed in No. 1 tall cans and covered with hot water. The cans were given a 11-minute exhaust, sealed, and sterilized 10 minutes. From the data in Table 4 it may be seen that dipping the hard-ripe figs in a boiling 2 per cent sodium bicarbonate solution for 25 seconds and Table 4. Effect of combination of bicarbonate dip and boiling-water blanch on texture - Length of - Maturity Type of dip Legiilfnftfsfu’ blanch 1 Obsjgfcjfff: °“ (minutes) 1 . . . i I Hard rlpe 2% sodium bicarbonate 25 ' 1 ] poor Hard ripe 2% sodium bicarbonate 25 2 poor Hard ripe 2% sodium bicarbonate 25 3 i good Hard ripe 2% sodium bicarbonate 25 | 4 I excellent Hard ripe 2% sodium bicarbonate 25 5 fair Ripe 2% sodium bicarbonate 15 1 poor Ripe 2% sodium bicarbonate 15 I 2 poor Ripe 2% sodium bicarbonate 15 l 3 good Ripe 2% sodium bicarbonate 15 1 4 excellent Ripe 2% sodium bicarbonate I 15 ) 5 good the ripe figs for 15 seconds, both dips being followed with a 4-minute blanch in boiling water, gave both lots of figs an excellent texture. Since the canning process would probably soften the figs somewhat, it seemed likely that a 3-minute blanch might be more desirable. This was amply verified by the examination of the canned samples one month later and by subsequent canning tests. Effect of Maturity To determine the effect of maturity on the quality of theicanned figs, hard-ripe and ripe fruit were canned, using the combination dip and blanch as described above. The figs were placed in No. 1 tall cans and covered with a 50° Brix (27.3 Baume’) cane-sugar sirup. The cans were IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 13 then exhausted in steam until the contents reached a temperature of 160° F., after which they were sealed and cooked at boiling-water tempera- ture for one hour. After several weeks and again after six months some of the cans were opened and the contents examined. The first observation was made by two and the second by nine individuals. The ripe figs and their sirup were found to have a richer amber appearance than the hard- ripe figs, of which both the fruit and the sirup had a greenish cast. The ripe fruit also had a much more pronounced fig flavor. Exhausting At various times during the experimental canning, observations were made to determine the length of exhaust in steam at atmospheric pressure (212° F.) needed to have the temperature of the fruit at 160° F. when the cans are sealed. When the figs were canned immediately after blanching and covered with sirup which had been heated to boiling, no exhaust was necessary. When the figs were canned in No. 1 tall cans immediately after blanching and filled with cold sirup, about a four- minute steam exhaust was required. When the figs were allowed to cool after blanching and then canned and covered with a cold sirup, about an eight-minute steam exhaust was needed for No. 1 tall cans. Cooking Ripe figs were canned in No. 1 tall cans; the best of the above-found methods were used after the cans had been sealed they were cooked at boiling-Water temperature for 30, 60, 90, and 120 minutes. Later examination of these samples showed that the 60-minute cook was the most desirable. The 30-minute cook left a slight green taste in the figs and the longer cooks gave no improvement over the 60-minute cook. Probably the length of cook needed will vary somewhat from year to year with the quality of the figs. Cooling l Ten minutes in running water at about 80° F. was found to be a suffi- cient time to cool the contents of No. 1 tall cans to prevent after-cooking, and to allow the cans to dry without rusting. Consumer’s Reaction _ To test the consumer’s reaction to the product several cases of figs in No. l tall cans were packed, using the best methods in the above experiments. (Cans were distributed t0 a representative lot of 50 people, who were ‘asked to give their opinion of the product. As a further check on the lllnethod of canning, individuals were questioned closely on the points which been under study in the experimental work. Those who were pleased the product were recorded as positive and those who were either indifferent or did not like the product were recorded as negative. The 1 ult of this test was 47 positive and 3 negative. 14 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION Recommended Procedure for Canning Figs in Light Sirup To simplify the conclusions which were drawn from the above experi- ments the following summary of the procedure found to be best for can- ning Magnolia figs in light sirup is given: 1. Select sound whole fruit slightly beyond the hard-ripe stage. 2. Remove stems. 3. Dip figs 15 to 30 seconds, the length of time depending upon the ripe- ness, in a boiling 2 per cent sodium bicarbonate (baking soda) solution. 4. Blanch dipped figs in boiling water 3 minutes. 5. Allow figs to drain for a few minutes and place in No. 1 tall tin cans. 6. Cover figs with a 50° Brix (27.3° Baume’) sirup containing 0.35 per cent of citric acid (based on the weight of the sugar). 7. Exhaust until contents of cans reach 160° F. 8. Seal cans and cook at boiling-water temperature for 60 minutes. 9. Cool cans in running water for 10 minutes. CANDIED FIGS Candied figs have been made commercially from Magnolia figs that had been preserved in cane-sugar sirup of about 28° Baume’ density. The sirup was drained from the figs, which were placed on screen trays and dried in a dryer until no longer sticky. The finished product was of good quality but the sugar had a tendency to crystalize on the outside of the fig in a short time. An objection to the method used was that since the sirup concentration was not built up to a very great degree in the figs, a very long drying period was necessary to finish them. Addition of Glucose The addition of glucose is a common method of preventing crystalization in candied fruits. Cruess (3) recommends the use of one part of glucose and two parts of cane sugar by weight in making up the sirup for candying fruits. Tests were made to determine the effect of various proportions of cane sugar and glucose on the appearance, texture, and flavor of can- died Magnolia figs made by the method outlined above. The figs used in the tests were of fair quality. The glucose used in the tests was in the form of a granulated sugar. Observations were made by numerous individuals,, including some who were connected with the preserving plants. Judging was done by observing and eating some of the candied fruit from each sample so that comparative results could be obtained. A final single observation on the samples was made about two months after the fruit had been candied. The results as given in Table 5 represent the opinions of the majority of those who examined the samples. IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 15 This table shows that forty per cent or more of glucose improved the appearance but where more than forty per cent of glucose was used both the texture and flavor were poorer. The effect of too much glucose Table 5. Effect of glucose on candied Magnolia figs gféasegllf s33; Per nstiftllgcose Appearan ce Texture } Flavor 100 0 poor l good I fair 80 20 fair l] good i fair 60 40 good good l fair 40 so good fair l poor 20 80 good fair poor 0 1 00 good 'll poor ll poor was to produce a tougher and more gum-like texture, and to give a less sweet and less pronounced fig flavor. With no glucose or only 20 per cent of glucose the candied fruit soon became covered with a hard crystalline coating of sugar. Modified Methods Several methods were tried out to find suitable ways for making candied Magnolia figs of good quality as cheaply as possible. It was found that lye-peeling could be eliminated if after the removal of stems the figs were dipped for 15 to 30 seconds in the boiling 2 per cent bicarbonate solution, as previously described, to remove the roughness of the skin. The time of drying at 120° F. could be reduced from 48 hours or longer required by figs that had been candied by the method formerly used to 12 hours or less when the sirup concentration was built up to about 70 per cent before drying. Two of the candying methods used that gave good results are as follows: (1) In the case of the riper figs the stems were first removed and the figs dipped in a boiling 2 per cent sodium bicarbonate solution for 25 seconds. After being rinsed in fresh water they were placed in the kettle and covered with a 30° Brix sirup made up with sixty per cent of cane sugar and forty per cent of glucose. The contents of the kettle were brought to a gentle boil and allowed to simmer a few minutes. The figs were left standing in the sirup over night and the next day the concentration of the sirup was increased to 40° Brix by the addition of sugar in the ratio of sixty per cent of cane sugar and forty per cent of glucose. The figs were again brought to a boil and again allowed to stand over night. This process was repeated each day, the concen- tration of the sirup being increased 10° Brix until it reached 70° Brix. 16 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION The figs were allowed to stand in the final sirup for a minimum of 48 hours, after which they were removed and allowed to drain. They were then dipped in warm water to remove the sirup from the surface and put on screen trays, which were placed. in the dryer at 120° F. Drying was more even if at the end of about 6 hours the figs were turned over on the trays. (2) Figs which were at the hard-ripe stage of maturity could be candied in a shorter length of time by the following process: They were either lye-peeled or dipped in the boiling 2 per cent sodium bi- carbonate solution and then rinsed in water. The prepared figs were added to a 16° Baume’ sirup containing sixty per cent of the sugar as cane sugar and forty per cent as glucose, and boiled until the sirup had reached a concentration of 28° Baume’ hot. They were allowed to stand in the sirup overnight and the next day the figs were boiled with the sirup until the concentration was 34° Baume’ hot. After standing in this sirup the figs were removed and allowed to drain, dipped in hot water, and dried at 120° F. as described above. Use of Acid It was found withripe figs that when citric acid was added to the sirup in which the figs were candied in the amount of 0.35 per cent of the weight of the sugar the flavor was improved. The calculated amount of acid was added with each addition of sugar to the sirup. Use of Pectin Dip After drying, some of the candied figs were dipped for one minute in a 1 per cent pectin solution, allowed to drain, and redried. The pectin solution was made up with water from a commercial powdered fruit pectin. These samples had a brighter appearance than those which were not coated with pectin. _ To determine if the pectin coating had any value in preventing stickiness due to the condensation of water on the surface of candied figs exposed to moist air they were dipped in 1, 2, 3, and 4 per cent pectin solutions for one minute, redried, and left exposed to the air for 6 days. The results as shown in Table 6 indicate that the pectin coating is of material Table 6. Effect of pectin dip Per cent pectin solution Length of dip Observation after 6 days 0 0 I sticky 1 1 minute slightly sticky 2 1 minute - very slightly sticky 3 1 minute not sticky 4 1 minute not sticky IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 17 aid in preventing stickiness. The pectin seems to form a tough film around the fruit which prevents the moisture from coming into contact with the sugar. For figs packed in cartons or boxes a one-minute dip in a 1 to 2 per cent pectin solution will probably be sufficient. PRESERVATION OF MAGNOLIA FIGS IN SULFUROUS ACID Sulfur dioxide as a gas or in solution with water has many uses in the fruit industry. It is an excellent preservative and has the property of combining with color compounds in the fruit to render them colorless. With most fruits the bleaching effect is temporary; for the original color of the fruit is gradually restored, owing to the loss of the sulfur dioxide through oxidation and volatilization. This property is utilized in the dried-fruit industry to preserve the color of light-colored dried fruits, which would otherwise become very dark in a short time if no sulfur dioxide were used. Sulfur dioxide is used as a temporary pre- servative for many fruits and fruit juices. More recently it has been used to prevent the darkening of apples which have been peeled and sliced for the bakers’ trade (5). Recent tests in California (6) have indicated that peaches may be temporarily preserved in sulfurous acid. Tests were made with Magnolia figs to determine if they could be preserved in sulfurous acid and what concentrations were necessary to hold the figs. A means of removing the acid so that the fruit could be made into finished products was also found. Effect of Concentration of Sulfurous Acid on Time of Keeping Magnolia figs at the hard-ripe stage of maturity were washed and ~placed in quart glass jars. A sulfurous acid solution was made by bubbling sulfur dioxide gas from a cylinder through water. This solution was diluted with water into solutions with concentrations of approximately 1000, 2000, 3000, 4000, and 5000 parts per million, as determined by iodometric titration. fSeveral lots of figs were covered with these solutions and the jars sealed and held for observation. At various intervals the figs were examined for appearance and texture. The results of these examinations over a period of one year, as given in Table 7, show that the figs in the solution of 1000 parts per million Table 7. Effective Concentration of Sulfurous Acid on Keeping Quality ppm so After 3 months After 6 months After 9' months After 12 months °rigiPal Appear- \ Texture Appear- Texture Appear- 1 Texture Appear- I Texture whltm“ ance ance ance ance 1000 good good good good spoiled .................................. .. 2000 good good good good good fair fair fair 3000 good good good good good fair good fair 4000 good good eirceil- good good good good good en 5000 excel- good excel- good excel- good good good lent lent lent 18 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION kept in good condition for about 9 months while those covered with the higher concentrations kept for over a year. Methods of Removal of Sulfur Dioxide Means for removing the sulfur dioxide from the figs that had been stored in a solution of 5000 parts per million were studied by trying various processes of leaching with water. The amount of sulfur dioxide remain- ing in the figs was determined by the volumetric iodine method (7). The figs that had 956 parts per million before treatment were reduced to 139 parts per million of sulfur dioxide by boiling in water for 2 hours. The water level over the figs was kept constant by frequent additions of fresh water. By covering the figs with water, heating to boiling, and draining off the water six successive times, the sulfur dioxide content was reduced to 307 parts per million. The effects of these leaching treatments are given in Table 8. Figs that had been placed in a solution containing Table 8. Effect of leaching with water on sulfur dioxide co_ntent Ppm SO Treatment after treatnient None ' 956 Boiled with water 30 minutes 248 Boiled with water 60 minutes 234 Boiled with water 90 minutes 201 Boiled with water 120 minutes 139 Covered with water, brought to boil, and water drained; 2 times. ......... .. 648 Covered with water, brought to boil, and water drained; 3 times .......... __ 394 Covered with water, brought to boil, and water drained; 4 times._....______ 360 Covered with water, brought to boil, and water drained; 5 times __________ __ 338 Covered with water, brought to boil, and water drained; 6 times __________ _. 807 956 parts per million of sulfur dioxide and that had been leached in six changes of water heated to boiling and then made into heavy sirup preserves, had only 34 parts per million at the end of the preserving process. This amount could not be detected by tasting the product. Since the removal of the sulfur dioxide is accomplished by dissolving it out of the fruit with water, it is probable that many of the soluble solids of the fruit are lost during the process. For this reason products made from figs preserved in this manner would not be comparable to the same products made from fresh figs. According to the Food and Drug Administration at Washington, D. C. investigations have failed to show that sulfur dioxide is likely to injure the health if not used in excess. Its use has, therefore, been permitted but the presence of sulfur dioxide in a food product which is shipped in interstate commerce must be plainly and conspiciously declared on the label. The Food and Drug Administration further states that some State laws contain specific injunctions against the use of preservatives. As the sulfur dioxide was removed the figs had a tendency to become hard and leathery. This can be prevented by adding 0.5 per cent of IMPROVED METHODS OF UTILIZING THE MAGNOLIA FIG 19 hydrochloric acid to the water that is used for leaching, following with a short fresh-water treatment to remove this acid. The use of the hydrochloric acid in dilute form is not objected to by the Food and Drug Administration so long as it is pure and is completely removed from the fruit. Products from Figs Stored in Sulfurous Acid Preserves made from figs which had been stored in sulfurous acid solution and leached in water to remove most of the sulfur dioxide cwere fair in appearance and texture but lacking in flavor. For this reason it is believed that the addition of artificial flavoring and perhaps coloring may be desirable in products made from these figs. A few tests were made in which mint flavor and one of the permissible green -coal-tar food dyes (1) were added to figs from which the sulfur dioxide had been removed by treatment with water; these figs were then made into preserves. These tests indicated that the figs would absorb the flavor and dye very readily. To conform with the Food and Drug Laws products made in this way should be plainly labeled to indicate the presence of sulfur dioxide as well as the fact that they contain artificial coloring and flavoring. AAJKNOWLEDGMENTS The author is indebted to R. H. Stansel for many suggestions made regarding the work and the writing of the manuscript, to M. S. Drake of the Mag-Tex Fig Association, who was very helpful in getting the work started, to Lester Liggett, who assisted in the laboratory work, to Max Retzer, who furnished some of the figs for the investigations, and to C. W. Johnston of the Virginia Smelting Co, who furnished the liquid sulfur dioxide used in the experiments. SLTMDLARY 1. The use of 2 per cent lye solutions for peeling figs was found to be satisfactory while the use of a stronger solution is inadvisable. 2. Dipping figs in an acid solution after the lye-peeling process slightly improves the appearance and flavor of the finished preserves. 3. Preserves of good flavor and texture were made from figs which had been given a preliminary dip in a boiling 2 per cent sodium bicarbonate solution to remove the roughness of the skin. 4. A new process for canned lVlagnolia figs in light sirup is given. 5. Methods for candying Magnolia figs in which the cost of produc- tion is lowered and the quality of the product improved are described. 6. Sulfurous acid has been found to be a good temporary preservative for Magnolia figs. 7. Most of the sulfurous acid can be removed by leaching the figs with water. . 8. Preserves made from the figs stored in sulfurous acid readily absorbed artificial flavor and coloring. 20 BULLETIN NO. 483 TEXAS AGRICULTURAL EXPERIMENT STATION LITERATURE CITED Ambler, J. A., Clarke, W. F., Evenson, O. L., and Wales, H. 1928. Chemistry and analysis of the permitted coal-tar food dyes. U. S. D. A. Dept. Bul. 1390. Chatfield, Charlotte and McLaughlin, Laura I. 1931. Proximate compo- sition of fresh fruits. U. S. D. A. Cir. 50. I Cruess, W. V. 1924. Commercial Fruit and Vegetable Products. McGraw-- Hill Co. Cruess, W. V. 1927. II Kadota fig products. Calif. Sta. Bul. 436: 43-44. Joslyn, M. and Mrak, E. M. 1930. Prepared Fresh Apples for Bakers’_ Usg. Fruit Products Journal, 9:309. Mrak, E. M. and Hendriques, V. 1932. Trial Shipment of Barreled Peaches t0 Germany. Fruit Products Journal, 11:142. Nichols, P. F. and ReedQH. M. 1932. Distillation Methods for the Determination of Sulfur Dioxide. Journal Industrial and Engineering Chemistry, Analytical Edition, 4:79. Stansel, R. H. and Wyche, R. H. 1932. Fig culture in the Gulf Coast Region of Texas. Texas Agr. Exp. Sta. Bul. 466:1-28. lI.F.JQ-l§“ll‘l~|d»ifi6-‘A‘.“.ll4v..‘llnl.j'uil»l rdsmbumx“, m‘... _.. " _.__,. _ H t; ‘ , \