THE EFFECT OF LARGE-SCALE METHODS OF PREPARATION ON THE VITAMIN CONTENT OF FOOD: II. THE CAROTENE, ASCORBIC ACID, NIACIN, THIAMIN, RIBOFLAVIN, PANTOTHENIC ACID, AND BIOTIN CONTENT OF CARROTS Headquarters, Military District of Washington Nutrition Laboratory Office of the Pentagon Post Restaurant Officer Washington 25, D. C. The Pentagon Pentagon Nutrition Laboratory Publication No. 2 1 December 191+5 THE OF LARGE-SCALE METHODS OF PREPARATION ON T®1 VITAMIN CONTENT OF FOOD*3 II. THE CAROTENE, ASCORBIC ACID, NIACIN, THIAMIN, RIBOFLAVIN, PANTOTHENIC ACID, AND BIOTIN CONTENT OF CARROTS. Investigation and Report by* Fred G. Koch, Major QMC Post Restaurant Officer The Pentagon Frank Streightoff 1st Lt., Sn. C., AUS Nutrition Officer Dr. Easel E. Munsell Dr. Ben-Ami Bon-Dor Martha Louise Orr Mary Haines Leonard Sarah R. Ezekiel The work described in this paper was done under a contract, recommended by the Committee caa Medical Research, between the Office of Scientific Research and Development and the Pentagon Post Restaurant Council. Acknowledgment is made to Lt. Col. Harvey K. Allen and to Dr. Robert S. Harris, Consultant in Nutrition to the Secretary of War, for their interest and initiative in organising this study and for their counsel and guidance so generously given in planning and carrying out this project. Appreciation is also expressed to members of the Working Committee composed of Dr. Robert S. Harris; Col. John B. You- mans and Maj. Wm. F* Ashe of the Office of the Surgeon General; Col. Paul P. Logan and Miss Jane C. Ebbs of the Office of the Quartermaster General; and Dr. Paul L. Pavcek, Secretary of the Food and Nutrition Board, National Research Council for their valuable assistance in selecting the foods to be studied and the methods of preparation and of assay to be used. Grateful acknowledgment is mad© of the advice and sugges- tions of; Dr. Esther L. Batohelder; Miss Gertrude M. Cox; Dr. Floyd S. Daft; Dr. Conrad A. Elvehjem; Dr. Faith Fenton; Com- mander Clive McCay; Dr. E. M. Nelson; Miss Lura Mae Odland; Miss Sybil L. Smith; and Dr. C. D. Tolle. 1 Carrots are the most important source of carotene in the Army garrison ration and in the quantity consumed they are their third most important vegetable* Dat6 available at the present time on vitamin retention in carrots are scant* It was the purpose of this study to determine vitamin losses in the large-scale preparation of carrots* REVIEW OF THE LITERATURE Carotene* A review of the literature shows the carotene content of carrots to vary from 25*6 mg* (1) to 2*3 mg. per 100 gm* (2)* A value of 12,000 I* D* vitamin A (7*2 mg* beta-carotene) per 100 gm* has been selected for the edible portion of fresh car- rots (3)* Values for carotene presented in the literature are given variously in terms of "carotene", "crude carotene", and "beta- carotene*" Recent work has shewn that "crude carotene" con- sists of several carotenoid pigments of varying biological ac- tivity* Of these carotenoid pigments, only alpha and beta caro- tene are present in carrots in important quantities (I4). Alpha carotene has been reported as having half the biological potency of beta carotene (5)* Harper and Zscheile (6) reported that the carotene of a number of garden varieties of carrots contained on an average - i«6 per cent alpha carotene. Kemmerer and Fraps (1*) found that the carotene of a number of samples of raw carrots con- tained 20 to 36 per cent alpha carotene and of boiled carrots, 23 to I4I per cent. Harper and gecheile (6) observed that frequently the depth of external coloring of a carrot is a rough index of the carotene concentration* In each variety of carrots studied except the Belgium White they found the carotene content of the phloem was greater than that of the xylem per unit length of root* Peterson (7,8) reported losses of carotene in the large- scale preparation of boiled carrots to be 6 to 23 per cent, but- tered carrots 12 to 13 per cent, and creamed carrots 9 per cent* Oser, et al. (9) prepared carrots in household quantities by waterless cooking and by boiling and found carotene losses of I4. and 6 per cent respectively* Pyke (10) obtained data which suggested no loss of carotene when carrots were steamed* 2 Fenton and coworkers (11) in a study of dehydrated carrots reported losses of carotene of 0 per cent in simmering in a stock- pot for 30 min.; 19 per cent in bringing to a boil (U5 min.) and simmering 20 min.; 5 per cent in pressure steaming (15 min.); and I per cent in boiling 25 min. In cooking dehydrated carrot bricks II per cent of the carotene was lost in bringing them to a boil (i+5 min.) and sirnnering 20 min. Ascorbic Acid. The ascorbic acid content of the carrot varies markedly. Two extreme values are 51 mg. (12) and 0.8 mg. per 100 gm. (13)* A value of 6 mg. per 100 gm. is given for the edible portion of fresh carrots (3)* The ascorbic acid concen- tration also varies between different parts of the carrot. Rudra (12) in his work on the Indian carrot found the skin to contain 75 mg. per 100 gm. and the flesh 31 mg. per 100 gm. Reported losses of ascorbic acid in boiling of carrots average 6l per cent (1, 7# 8, ll;-19), and range from 1+3 per cent (ll;.) to 77 per cent (15)* Most of these data were obtained in large-soal© cookery. Data reported for ascorbic acid losses after steaming of carrots by institutional methods vary over the small range of hi to 52 per cent (10, 14, 20). Similar results were obtained by Brinkman, et al. (17) who cooked carrots in a pressure saucepan and in a waterless cooker and found losses of ascorbic acid of 53 and 50 per cent respectively; and by Peterson (7» 8) who reported losses of h9 end 51 per cent in the preparation of buttered and creamed carrots. Daum, et al. (21) found on the other hand a 25 per oent loss in carrots prepared by an unspecified institutional method. Many investigators have reported losses of ascorbic acid in cooked carrots held on a steam table for various lengths of time (10, lU, 17, 18, 20, 21). A typical example was reported by Hig- gins (li*) who found that carrots which lost 52 per cent of their ascorbic acid during steaming, lost an additional 21 per cent when held on the steam table 1 hr. Capps and Flanagan (22) found that destruction of asoorbic aoid increased as the cooking period was lengthened. Carrots boiled 15 min. lost hi per cent ascorbic acid but those boiled 60 min. lost 60 per cent. Niacin. The niacin content of raw carrots as reported in the literature varies from .22 mg. (23) to *71 mg. per 100 gm. (1). A value of .5 mg. per 100 gm. has been selected for the edible por- tion of fresh carrots (3)* Oser, at al. (9) prepared carrots in small quantities by a waterless method and by boiling and found losses of niacin of 1 and 29 per cent respectively# Heller, ©t al# (13) found a loss of 1*5 per cent in carrots boiled in. large quantities. Data on niacin content of raw and cooked carrots reported by Pyke (10) would indicate a loss of li* per cent when calculated on the dry weight basis# Fenton and coworkers (11) in an investigation of dehydrated carrots found niacin losses of 32 per cent in simmering in a stock-pot 30 min.; i*5 per cent in bringing to a boil (1*5 min#) and simmering 20 min.j 58 per cent in pressure steaming; and 1*2 per cent in boiling. In cooking dehydrated carrot bricks 1*2 per cent of the niacin was lost in bringing them to a boil (1*5 min#) and simmering 20 min. As this vitamin is quite heat stable, the ‘•lost* portion can usually be found in the cooking water; for instance, Russell, ot al# (2l*) found 72 to 85 per cent of the original niacin con- tent in the cooked carrots, and 5 to 12 per cent in the cooking water# Thiamin. The thiamin content of raw carrots as reported in the literature varies from .025 mg* (23) to #100 mg. per 100 gm. (25)• A value of #07 mg* per 100 gm# has been selected for the edible portion of raw carrots (3)« Heller, ©t al. (15) in their study of large-scale cooking reported that 52 per cent of the thiamin was lost in boiling. Hagel and Harris (20) studied the effect of an institutional method of steaming and reported a 25 per cent loss# Fenton and coworkers (11) found thiamin losses in preparation of dehydrated carrots of 1*3 per cent in simmering 30 min#; 25 per cent in bringing to a boil (1*5 min.) and simmering 20 min#; 1*8 per cent in pressure steaming; and 1*8 per cent in boiling (25 min.). In cooking dehydrated carrot bricks 1*3 per cent of the thiamin was lost in bringing them to a boil (1*5 min.) and sinmering 20 min# Hinman, et al# (17) found an average thiamin loss of 1* per cent in family site portions of canned carrots prepared by concentrat- ing the liquid, adding the solid portion and heating. When the same investigators boiled canned carrots by a typical Army method (18) they found that the boiled carrots contained only 61* and 68 per cent of the original thiamin content and the boiling water 30 and 2? per cent# The actual thermal destruction of thiamin, amounted, therefore, to only 5 end 6 per cent. Riboflavin* The riboflavin content of raw carrots as reported in the literature varied from *01+0 to .10 mg. per 100 gm. (23)* A value of *06 mg. per 100 gm. has been selected for the edible por- tion of fresh carrots. Heller, et al. (15) in their study of large-scale cooking found a loss of 6l per cent riboflavin when carrots were boiled. Pyke (10) found a loss of 7 per cent (calculated on the dry weight basis) in carrots boiled in an Army Student Training Pro- gram mess. Fenton and coworkers (11) prepared dehydrated oarrots in a number of ways and found riboflavin losses of 26 per cent in simmering 50 min.; 11 per cent in bringing to a boil (U3 min.) and simmering 20 min.; 35 per cent in pressure steaming; and 39 per cent in boiling. In cooking dehydrated carrot bricks 1*5 per cent of the riboflavin was lost in bringing them to a boil (U5 min.) and simnering 20 rain. Hinxnan, et al. (17) found slight gains of riboflavin when canned carrots were heated in the concentrated canning liquor as described above. Pantothenic Acid. The literature available on the pantothenic acid content of carrots is at present scant. Values reported range from .12 mg. (23) to 3»2 mg. (1) per 100 gm. Pyke (10) reported data on raw and cooked carrots which would indicate a loss of 17 per cent of pantothenic acid in cooking, when calculated on a dry weight basis. Biotin. Cheldelin and Williams (26) reported that samples of carrots contained an average of ,.0025 mg. biotin per 100 gm. PLAN OF THE EXPERIMENT The general plan for this investigation was similar to that followed in a previous study on potatoes (27), except that the methods of preparation were limited to boiling and steaming. For each of* those methods of preparation, determinations were made on a sufficient number of replicate samples, usually 10, to furnish data suitable for statistical analysis. The plan of determining the batch weights at successive stages in the preparation was used as previously described (27). It was of particular value in the case of carrots since the leaching of solid matter into the cooking water was even more marked than in the case of potatoes. The analyses included determinations of dry solids, hydrogen ion concentration, and content of carotene, ascorbic acid (total and dehydro), niacin, thiamin, and riboflavin. Through the kind- ness of Dr. C. A. Elvehjem, pantothenic acid and biotin determine tions were made at the Department of Biochemistry, University of Wisconsin, on composites prepared from the replioate B-oomplex samples. Study I. The carrots for this study were obtained from the general supply for the Pentagon Post Restaurants. The different batches of carrots varied considerably in size, depth of color, degree of maturity, freshness, and variety. Differences in vita- min content from batch to batch were also marked. Study II. To eliminate some of the variables obtained in the first study, a second study was made with carrots of a single variety and of a single purchase-lot. Twelve orates of the Chan- tenay Coreless variety were obtained from a producer in the Im- perial Valley, California. The carrots were received in prime condition with tops. After a week’s storage, it was necessary to remove the tops from all the remaining carrots to reduce wilt- ing and deterioration from fungus diseases. EXPERIMENTAL PROCEDURE Methods of Preparation of Carrots and Selection of Samples The methods of preparation selected are those used in the Army mess and other installations where large numbers of people are fed. In some installations carrots are prepared for cooking by peeling in a mechanical abrasive peeler, and in others they are cleaned with water and a stiff brush. Boiling is a common mess practice and steaming is typical in large restaurants and consolidated messes. Study I. The batch of carrots intended for a day’s rtn was sorted 'by setting aside every 10th carrot for the raw un- peeled sample. These carrots were washed by hand, trimmed of tops and roots, and sliced into disks in a pcarered vegetable slioer with blades set at 3/8 in. This sample was thoroughly mixed and used immediately for preparation of subsamples. This mixing and immediate subsampling was the general practice for all raw samples* 6 The remaining carrots, approximately 1+5 lb** were peeled in a mechanical abrasive peeler for 2 min* and then drained. The machine did not peel unsound carrots; these therefore could be detected and discarded. Green and purple epidermis and woody stalk parts were removed. The peeled carrots were then sliced by the machine into one large container and slices from every part of the container were used for the samples for the raw peeled and for the various cooking procedures. For boiling, about 25 lb. of carrot slices were placed in a 20 gal. tinned iron pot (small areas of iron were usually ex- posed), and covered with boiling water. The water was then brought back to a vigorous boil, 100 gm. of sugar and 100 gm. of salt were added, and the boiling continued until the carrots were tender, usually 1+5 min. For steaming, approximately 6 lb. of the Carrot slices were placed in 1 gal. stainless steel pans and cooked in a free-venting vegetable steamer until tender, usually 25 min. For holding, quantities of the boiled or steamed slices were placed in 1 gal. stainless steel pans and kept on the steam table for 1 hr. Samples were prepared of carrotss raw, unpeeled; raw, pealed; boiled; boiled, held 1 hr.; steam; and steamed, held 1 hr. Water from the boiled carrots was also sampled. Study II. Sixty lb. of Chantenay Coreless carrots were used for each run. An approximately equal weight of carrots was taken from each of the 12 crates. The tops and any green epidermis were removed. The carrots were cleaned in water with a stiff brush, and, without previous peeling, were sliced in the mechani- cal slicer. The method of distribution of slices among the vari- ous samples and the subsequent cooking procedures was the same as in Study I, except that no sugar or salt was added. Samples were prepared as in Study I except that there was no sample for raw, unpaeled. When Study II was completed, the remaining Chantenay Coreless carrots (266 lb.) were used for a special study on the relationship of carotene content to the physical characteristics of raw carrots. These carrots were separated into 3 groups according to weight, and a sample from each group prepared for carotene analysis* For a second test, 50 medium weight carrots were arranged according to depth of external coloring. The two darkest, the two lightest, and the two of median coloring were individually assayed for caro- tene • 7 Subsamples for Analysis All subsamples for vitamin assay except those from the boiling water samples were prepared for analysis by slurrying with a stabilizing solution in a Waring blendor, and ware storod in brcwn glass bottles in a refrigerator room maintained at U0° F. There are considerable variations between the inner and the outer parts and among top, middle, and bottom portions of the carrot. This fact and variations among individual carrots, made it essential that subsamples represent as many slices as possible For the subsamples of the raw carrots, largo numbers of slices were selected at random from the entire sample. The slices were halved crosswise to give comparable subsamples for total and dehydro ascorbic acid. In the case of the cooked carrots, ascorbic acid subsamples were prepared as for the raw. The remainder of the cooked sample was chopped thoroughly with a knife and mixed before aliquots were taken for the other sub- samples. Subsampling for ascorbic acid assays was completed within 15 min. of the time the samples were received in the laboratory. Subaamples of carrots for the determination of total ascorbic acid were made by slurrying 60 gm. of carrot and 180 ml. of 5 per cent metaphosphoric acid. For the subsampla of boiling water, 150 ml. of the water and 50 ml. of 20 per cent metaphos- phoric acid wore used. Sixty gm. of carrot and 180 ml. of 5 per cent metaphosphoric acid containing 1 per cent thiourea were used in preparation of the dehydro ascorbic acid subsamples. Ascorbic acid assays were made within hr. after preparation. Subsamples for the determination of niacin, thiamin, and riboflavin wore made by slurrying 150 gm. carrot with 300 ml. 0.1 N For the subsamples of boiling water, 2?0 ml. of the water and 50 ml. of IN HgSOi were used. A small amount of chloroform was added to the B-complex subsamples. When all runs had been completed for Study II, composite subsamples for the determination of pantothenio acid and biotin were prepared for each stage of preparation by pooling 30 gm. of slurry from each of the 10 replicate B-complex subsamples for that stage. 8 Subsamples for the determination of percentage dry solids were made by slurrying 75 gm. carrot with 130 ml* distilled water* The boiling water was not diluted* Hydrogen ion con- centration was determined on portions of the dry solidssuV- samples* Subsamples of raw and cooked carrots for carotene analysis contained 100 gm* of carrot slurried with 1*00 ml. of J per cent KOfl in 32 per cent ethanol. These preparations were of such a consistency that representative aliquots for assay could be taken with a calibrated inverted pipette. Subsamples of boiling water contained 150 ml# of the water and 130 ml. of 3 per cent K0H in 32 per cent ethanol* Methods of Analysis Carotene was determined by the method of Ben-Dor, et al* (28). Carotene as determined by this method is approximately equivalent to "pure" carotene as determined by the AQAC method. Biotin was assayed according to the procedure of Shull, et al. (29), using the modified basal medium of Shull and Peterson (30)• The samples were hydrolysed for assay by autoclaving with I4N H2SO1 for 2 hr. at 15 lb* Extracts for pantothenic acid assay were prepared and assayed according to the procedure of Neal and Strong (31) with the modifications introduced by Ives, et al. (52)• All other determinations wore made as previously described (27) with the following exceptions* 1) the incubation period for niacin and riboflavin cultures was uniformly 72 hr., and 2) the riboflavin extracts were prepared by autoclaving the subsamples in the presence of IN at 15 lb. for 30 min. RESULTS Data on vitamin content, dry solids and hydrogen ion concen- tration of carrots at all stages of preparation in each of the two studies are summarised in Tables 1 and 2. For the raw, un- peeled carrots a range as well as the average is given. Tables 1 and 2 also present per cent vitamin retention in the oarrots at the different stages of preparation. These percentages are the averages of the percentage retentions calculated for indivi- dual batches (27)* Since in Study I oarrots were peeled before cooking, the per cent retention in that study was oaloulated on the basis of the raw, peeled oarrots as 100. In Study II the oarrots were cooked without peeling, and the raw, unpeeled was used as 100. Differences between per cent values for the various stages and methods of preparation were calculated (Table 3) to determine the relative effects of peeling, boiling, steaming and holding* The significance of each difference was assessed by comparison with the Least Significant Difference (93 P®r cent) calculated according to Student’s t method (27)• The mechanical peeling of carrots brought about significant decreases in concentration of carotene, ascorbic acid (total and dehydro), niacin, thiamin, and riboflavin* On the basis of 100 per cent for the unpeeled, the percentage concentration in the peeled was* for carotene, 95*5 per cent; total ascorbic acid, 9ii*3 per cent; reduced ascorbic, per cent; niacin, 7U*7 per cent; thiamin, 86*9 P®r cent; and riboflavin, 88*5 per cent. Niacin, thiamin and riboflavin are apparently more highly con- centrated in the portion removed by peeling* Decrease in weight from peeling the stored carrots (Study I) was 16*7 lb. per 100 lb. Boiling resulted in highly significant losses of ascorbic acid, niacin, thiamin and riboflavin* For the two studies the losses were as follows: total ascorbic acid, 73 aud 58 per cent; reduced ascorbic acid, 79 and 65 per cent; niacin, 7 and per cent; thiamin, 50 and U+ per cent; and riboflavin, 3U and 30 por cent* Loss* of pantothenic acid was i+6 per cent and of biotin 18 per cent (Study II)* Carotene losses were small in both studies and only one loss was significant, that of 5 par cent in Study II* For the two studios, the water in which the carrots were boiled contained: 16 and 27 per cent of the total asoorbio acid, 51 and I4I4. per cent of the niacin, and 38 per cent of the thiamin, and 58 and I42 per cent of the riboflavin present in the raw carrots* The boiling water also contained I4I per cent of the pantothenic acid and 29 p®r cent of the biotin present in the raw carrots* It is apparent, therefore, that vitamin losses in the boiling of carrots are due largely to extraction by the cooking water* Steaming also resulted in highly significant losses of total and reduced ascorbic acid* For the two studies the losses were 38 and 37 p®r oent for total ascorbic acid and I4I4. and 38 per cent for reduced ascorbic acid* Losses of niacin and thiamin were significant in both studies but not as great as those of ascorbic acid* The losses were 16 and 12 per cent for niacin and 18 and 16 per oent for thiamin* Losses of ribo- flavin were small and significant only in Study II — 8 per cent* ■►Significance of these losses could not be determined since the assays for each stage wore made on single samples composited of aliquots from the replicate samples* Pantothenic Acid showed a gain of 7 per cent; biotin a loss of U per cent and carotene a loss of 7 per cent.* A comparison shows that the steamed carrots retained a much higher percentage of all vitamins studied than did the boiled car- rots. In the two studies the steamed carrots retained 35 and 21 per cent more total ascorbic acid, 35 and 27 per cent more reduced ascorbic acid, 31 and 31 per cent more niacin, 32 and 28 per cent more thiamin, and 26 and 22 per cent more riboflavin. Retention of pantothenic acid was 53 p©r cent greater, and of biotin li* per cent greater in the steamed than in the boiled carrots.* Reten- tion of carotene was practically the same for steaming and boil- ing — 93 and 95 per cent. Holding cooked carrots on the steam table for 1 hr. resulted in significant decreases in ascorbic acid content only. Boiled and steamed carrots lost respectively, 6 and 8 per cent of total ascorbic acid (Study II); losses of reduced ascorbic acid were 7 and 16 per cent in Study I and lit and 2i* per cent in Study II. In carrots cooked or cooked and held, dehydroascorbic acid comprises a greater proportion of the total ascorbic acid present than in raw carrots; the per cent losses of reduced ascorbic acid from cooking and holding were greater than those of total ascorbic acid. In the case of Chantenay Coreless carrots cooked and held 1 hr. the actual content (mg. per 100 gm.) of dehydro ascorbic acid was greater than in the original raw carrots. The carotene content of the carrots grouped according to weight and of those selected according to depth of external coloring is shown belowj Wt. Rang© Total Wt. of Group Carotene gm. lb. mg./lOO gm. 18 - 60 56 7.0 16 - 100 159 7.8 101 - 200 71 8.3 ♦Significance of these losses could not be determined since the assays for each stage were made on single samples composited of aliquots from the replicate samples. Color No. Samples Carotene mg./lOO gm. Dark orange 2 12 .6; 1J.^ Median 2 8.0; U.o Pal© orange 2 6.8; 8.0 These results indicate that carotene content does not vary greatly between large and small carrots of the same variety, but that depth of external coloring is a good index of the carotene content of individual carrots. Since the various carotene fractions have different biological values as sources of vitamin A, the carotene from one set of samples of raw and cooked carrots was fractionated into alpha and beta caro- tene. The carotene of raw carrots was 22 per cent alpha and 78 per cent beta carotene. The carotene of the cooked carrots gave values of 19 to 22 per cent alpha and 81 to 78 per cent beta carotene, in- dicating no significant differences in the proportion of these two components in the raw and cooked carrots. DISCUSSION Carotene is the most important vitamin in carrots. The data presented show that carrots cooked by boiling or steaming retain practically all of their original carotene and are thus to be con- sidered at least as valuable as raw oarrots as a potential source of vitamin A. Steaming of carrots results in a markedly greater retention of ascorbic acid, niacin, thiamin and riboflavin than does boiling; the loss of solids is also much less in steamed than in boiled car- rots. In addition, steamed carrots have better flavor, brighter color and a more pleasing texture. Vitamin retentions in the peeled and cooked oarrots represent- ing stored carrots of several varieties (Study I) and in the un- peeled and cooked fresh Chantenay Coreless oarrots (Study II) showed close agreement. Significant differences between corres- ponding values from the two studies existed only in the case Of, 1) thiamin retentions for carrots boiled and held and 2) of ribo- flavin retentions for the boiled carrots plus the boiling water. From these results it is apparent that vitamin losses due to cooking peeled stored carrots are similar to those duo to cooking of uppeele 13 ~u -T 9 - 3 m Steamed - Boiled - _ • -35 9 -35 13 -31 7 -32 8 - 26 11 Steamed, held - Boiled held Carrots, Chantenay Coreless (Study II) -55 10 -25 13 7 9 9 Raw - Boiled Raw - Boiled plus - 8.1 - 1 h -58 5 -65 6 2 -a 3 . 30 6 Boiling Water - - h - -31 7 - - 1 5 - 6 3 12 5 Boiled - Boiled, held 5.5 0 - h "it 3 0 2 2 5 u 3 Raw - Steamed - 9.3 - 7 _ -37 7 -38 10 -12 3 -16 2 - 8 3 Steamed - Steamed, held • 3 0 - 5 -15 7 - 2 5 1 2 0 3 Steamed - Boiled - m -21 U -27 6 -31 h -28 3 - 22 i* Steamed, held - Boiled, held ♦ Differences were derived from per cent vitamin retention -I9 values k -IT given in Table !• 5 -2T k -2 3 - 2? h ** Differences as great as or greater than the value calculated as the least significant difference are considered as significant. These are underlined. A negative sign is used when the vitamin no sign is used when the reverse is true. / See text for method by which the least significant difference 1< content of ►s.d. (95*) the first stage is calculated. is greater than that of the second stage 1 Table 3 - Differences* in Per Cent Vitamin Retentions between Stages in the Large-Scale Boiling and Steaming of Carrots, with a Test of their Significance bibliography (1) Pyke. W.E. , Colorado Prog* Notes on Nutrition Research No. 2. Colo. Agrio. Exp. Sta. Misc. Series Paper No. 229, 19U1+* (2) Gardner, J., Pepkowitz, L.P., and Owens, 3.H. , The carotene and ascorbic acid content of a number of Rhode Island fresh vegetables and fruits. R.I. Agric. Exp. Sta. Prog. Notes. No. 3, 19U3. (3) Nutritive value of common foods. Bureau of Human Nutrition and Home Economics, U.S.D.A. and the Committee on Food Composition, N.R.C., 191+5* (Unpub.) (14.) 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Nutrition. 26» 577# 1943* (16) Brinkman, S.V.S., Halliday, E#G*, Hlnman, W.F*, and Hanmer, R.Jo Effect of various cooking methods upon subjective qualities and nutritive values of vegetables* Food Re- search, 7i 300, 19i|3 • (17) Hinman, W.F., Brush, M.K., Halliday, E.Go The nutritive value of canned foods. VII. Effect of small-scale pre- paration on the ascorbic acid, thiamin, and riboflavin content of commercially canned vegetables* J. Am. Dietet. A., 21t 7, 1945. (18) Hinman, W.F., Brush, M.K*, Halliday, E.G*i Ihe nutritive value of canned foods. VI* Effect of large-scale pre- paration for serving on the ascorbic acid, thiamin, and riboflavin of commercially canned vegetables. J. Am. Dietet. A. 20j 732, 1944* (19) Orent-Keiles, B., Hewston, E.M. and Butler, L.E.t Nutri- tive value of vegetables served at an army mess. (Unpub.), 1944. (20) Nagel, A.E., and Harris, R.So Effect of restaurant cooking and service on vitamin content of foods. J. Am. Dietet* A., 19t 23, 1943. (21) Daum, K., Aimone, M. and Holister, So Ascorbic acid in in- stitutional food. J. Am. Dietet. A. 19* 593* 1943- (22) Copps, J*D., and Flenagan, Co Ascorbic acid content of vegetables* Ala. Agrio. Exp. Sta. Mimeo* Report No* 4* 1943. (23) Morgan, A.F., Carl, B*C., Hunner, M.C., Kidder, L.E*, Hummel, M*, and Peat, J.Mo Vitamin losses in commercially produced dehydrated vegetables, cabbage, potatoes, carrots, and onions. The Fruit Products J* and Am. Food Manufacturer, 23* 207. 1944. (2i±) Russell, W*C., Taylor, M.W. and Beuk, J*F*» The nicotinic acid content of common fruits and vegetables as prepared for human consumption* J* Nutrition, 25 j 19l*3* (25) Baker, A*Z* and Wright, M*D*i The vitamin content of foods* Bioohem* J* 291 1802, 1935* (26) Choldelin, V.H* and Williams, R.J** The B vitamin content of foods. Studies of the Vitamin Content of Tissues II* U* of Texas Publication No* 1*327* 19l*2* (27) Streightoff, F., Munsell, H.E*, Ben-Dor, B., Orr, M.L., Cailleau, R., Leonard, M.H*, Ezekiel, S.R., Komblum, R., and Koch, F*G*j The effect of large-scale methods of preparation on the vitamin content of food? I* The ascorbic acid, niacin, thiamin, and riboflavin content of potatoes* J. Am* Dietet. A* 22, February 191*6* (28) Ben-Dor, B*, Streightoff, F., and Koch, F.G.t A method for the determination of carotene in vegetables* (Unpub*) 19U5. (29) Schull, G.M., Hutchings, B*L* and Peterson, W.H.: J. Biol* Chem. li*2: 913* 191*2. (30) Schull, G*M* and Peterson, W*H*» J* Biol* Chem* 151* 201, 19U3* (31) Neal, A*L* and Strong, F*M*t Ind* and Eng* Chem*, Anal* Ed. 15j 65k, 19i*5. (32) Ives, M., Zepplin, M., Ames, S.R., Strong, F.M* and Elvehjem, C.A. » J* Amer* Dietet* A* 21* 337* 19l*5« APPENDIX VITAMIN CONTENT, PER CENT DRY SOLIDS, BATCH WEIGHT, AND pH OF CARROTS AND INGREDIENTS AT VARIOUS STAGES IK PREPARATION Carrots, Boiled and Held, Steamed Batch I through Batch XIV Miscellaneous Variety No. Description Batch Wt. Dry Wt. pH Caro- tene Asc. Tot. Acid Red. Nia- cin Thia- , min Ribo- flavin units % mg./lOO gm. Batch I 1. Haw, Unpeeled 122.2 12.6 5.7 10.0 5.93 •52 .71* .058 •QM+ 2. Raw, Peeled 100.0 11.8 6.0 8.35 6.68 .88 •53 .037 .036 3* Boiled 67-9 10.1 6.0 7.27 3.23 •57 .1+0 .027 .033 1+. Boiling Water 89-5 1+.5 5*9 .05 1.19 — .21+ .012 .018 5* Boiled, Held 93.0 9.8 3.9 8.25 2.20 .1*9 .36 .027 .032 Batch II 1. Raw, Unpeeled H7.9 13.1 6.3 9.9 5.98 .61+ • 71 .060 .061 2. Raw, Peeled 100.0 12.3 6.1; 8.05 5.52* 1.17 .68 .01+3 .01+1 3« Boiled 90.7 9.8 5.9 10.2*5 2.02 .51+ •39 .026 .052 I*. Boiling Water 101.0 5.5 5.7 .06 .66 — .28 .013 .021 5. Boiled, Held 96.2 9.6 5.8 8-35 1.51* .65 .36 .023 .030 Batch III 1. Raw, Unpeeled 120.7 13.2 6.3 12.15 5.60 .28 .95 .068 .051 2. Raw, Peeled 100.0 12.1+ 6.1* 13.1 5.83 .18 .71 .051* .051 3* Boiled 89.7 10.5 5.8 11.5 1.88 .32 .38 .029 .036 i+. Boiling Water 126.0 1+.6 5.7 .03 .85 — .27 .018 .022 5. Boiled, Held 96.0 9.5 5.8 12.0 2.5J+ •51+ .32 .027 .033 Batch IV 1. Raw, Unpeeled 117.8 12.9 6.3 10.0 5.10 .77 .77 .058 .050 2. Raw, Peeled 100.0 12.6 6.1+ 13.2 6.1+1 .89 .71 .052 • 01+2 3» Boiled 90.9 9.8 5.9 11.9 1.95 .36 .37 .021+ .032 i+. Boiling Water 92.2 1+.7 5.7 .06 .90 .021 .022 5. Boiled, Held 98.6 9.2 5.8 11.1 1.95 1.08 .1+0 .031 .033 Batch V 1. Raw, Unpeeled 120.7 12.6 6.0 11.35 5.88 .77 .76 .060 .01+1 2. Raw, Peeled 100.0 13.0 6.1; 10.65 5.31 •1*9 .58 .051+ .038 3* Steamed 88.1 12.6 5.9 10.1 3.33 .71 .56 .01*7 .01+0 1+. Steamed, Held 89.3 12.2 5.9 11.1 3.96 2.30 • 38 • 01*7 .038 Batch VI 1. Raw, Unpeeled 128.1+ 12.6 5.9 5.17 I.03 .97 .067 .061 2. Raw, Peeled 100.0 11.8 6.1+ 5.20 .82 .67 .056 .01*9 3» Steamed 92.3 12.0 6.0 3.16 •75 .61 .050 .01+6 1+. Steamed, Held 91.7 12.7 3.6 3.29 1.22 .67 .052 .01+6 (Appendix) 20 No. Description Batch Dry pH Caro- Asc. Acid Nia- Thia- Ribo- Wt. Wt. tene Tot. Red. cin min flavin units % mg. 1 8 H Batch VII 1. Raw, Unpeeled 119.3 12.3 6.1 5.83 .75 .69 .057 .01+6 2. Raw, Peeled 100.0 12.7 6.3 4.29 •h5 .63 .052 .044 3* Steamed 87.3 12.5 6.0 5.40 .53 .61+ .050 .053 I*. Steamed, Held 88.8 13.1 6.0 2.70 1.06 .62 .01+0 .01+1+ Batch VIII 1. Raw, Unpeeled 118.2 ll+.l 6.2 6.17 .90 • MD ro .060 .050 2. Raw, Peeled 100.0 13.3 6.5 5.72 .50 .79 . 0 VD OO .045 5* Steamed 89.8 12.2 5.9 4.29 .76 .69 .055 .01+1 It* Steamed, Held 91.6 13.5 5-8 3.76 1.01+ .72 .050 .045 Batch IX 1. Raw, Unpeeled 115.lt 13.5 6.6 12.3 6.81 .48 .89 .076 .057 2* Raw, Peeled 100.0 12.0 6.5 10.85 5.61 1.05 .70 .065 .049 3. Boiled 9it.l 9.1 6.1 12.1 1.20 .63 -k2 .036 .033 I*. Boiled, Held 101.1 8.7 6.0 11.1 .76 .58 • 39 .033 .033 5* Boiling Water 108.9 5.1 5.9 .01+ .83 —' .36 .028 .025 Batch X 1. Raw, Unpeeled 116.8 12.7 6.2 10.1 5.87 .26 1.01 .077 .057 2* Raw, Peeled 100.0 11.9 6.1+ 10.8 5.25 •56 ♦69 .074 .01+8 3* Boiled 99-9 8.9 6.0 10.1+ 1.13 -13 .1+0 .034 .032 k- Boiled, Held 107.6 8.5 5.9 11.3 1.21 .60 .38 .033 .031 5* Boiling Water 121.1 5.0 5.7 .06 .53 -- .35 .030 — Batch XI 1. Raw, Unpeeled 111.0 13.6 6.3 11.8 5.75 1.13 1.20 .082 •0l+6 2* Raw, Peeled 100.0 12.1+ 6.2 11.3 5.15 .58 .98 .074 .01+2 3. Boiled ‘ 92.1 9.1 5.8 11.8 1.49 .62 .51 .036 .026 1+. Boiled, Held 99.5 8.8 5.9 11.6 1.18 .90 .50 .032 .030 5* Boiling Water 113.5 5.3 5.7 .01+ 1.11+ —— •48 .029 .025 Batch XII 1. Raw, Unpeeled 126.1* 12.7 6.2 10.2 5.21 .58 1.1+6 .080 .050 2. Raw, Peeled 100.0 12.1 6.2 8.8 5.77 .56 1.23 .073 .045 3* Boiled 97.6 9.5 5.8 9.0 1.39 -13 .65 .01+0 .030 1+. Boiled, geld 102.6 9.2 5.8 8.2 1.35 l.oo .68 .01+0 .028 5. Boiling Water 102.7 5.1 5.7 —- •93 — .50 .026 .027 Batch XIII 1. Raw, Unpeeled 125.7 13.1 6.2 12.5 5.81 CD H • 1.15 .083 .053 2* Raw, Peeled 100.0 12.3 6.1+ 11.9 5.60 1.21+ 1.00 .073 .045 5* Boiled 97.0 8.1+ 6.0 11.3 1.15 .76 .50 .037 .026 h. Boiled, Held 102.0 8.1; 5-9 10.5 1.00 .65 .50 .034 .021+ 5* Boiling Water 11+1+.8 i+-5 5.8 — .85 — •hh .029 .020 21 (Appendix) No. Description Batch Dry pH Caro- Asc. Acid Nia- Thia- Ribo- Wt. Wt. tene Tot. Red. cin min flavin K units =/ /• mg. 1 0 0 H Batch XIV 1* Raw, Unpeeled 119.8 12.7 6.2 10.2 5.93 .96 l.li; .075 .055 2. Raw, Peeled 100.0 11.6 6.k 8.9 5.21 1.19 .91; .075 .033 3. Boiled 96.8 9.1 6.0 10.4 1.27 .51 .52 .035 .028 1*. Boiled, Held 102.0 8.0 6.0 9-1* •71 •58 .52 .031* .020 5. Boiling Water 136.8 U*3 5.8 — .38 — .1*1 .027 .019 Batch XV through Batch XXIV Chantenay Coreless Variety Batch XV 1. Raw, Unpeeled 100.0 12.1 6.0 7.1* 6.1* .1*8 .70 .065 .065 2. Steamed 88.6 12.u 6.1 — 3.3 .76 .61; .056 .061 3» Boiled 90.9 9.6 6.0 8.0 2.0 .76 .1*1* .037 •01*5 Steamed, Held 89.8 12.1; 6.0 — 3.0 1.60 .61* .059 •066 5. Boiling Water 77.7 1**9 5.8 — 2.1* — •37 .029 .036 6. Boiled, Held 96.7 9.3 6.0 8.0 2.1 1.52 .1*2 .037 .01*1 Batch XVI X* Raw, Unpeeled 100.0 13.0 6.2 8.1; 6.6 .72 .69 .068 .068 2. Steamed 91.7 12.7 6.0 — k»3k •1*5 .68 .063 .065 3. Boiled 92.0 9.9 5.9 8.6 2.81* .73 .1*6 .01*3 .01*1* I4.. Steamed, Held 91.7 13.1 5.9 — 3-98 1.33 .60 .063 .069 5. Boiled, Held 96.0 10.0 5.9 8.2 2.55 1.1*3 .1*2 •ol*5 • 0l*l* 6. Boiling Water Batch XVII 1. Raw, Unpeeled 100.0 12.6 6.0 9.6 5.82 •17 .68 .066 .063 2. Steamed 91.5 12.8 6.0 — u.23 .1*6 .61* .060 .065 3* Boiled 90.9 9.7 6.0 8.9 3.08 .56 .1*3 •01*3 .051 1*. Steamed, Held 90.0 13.3 6.0 — u.35 1.29 .67 .063 .068 5. Boiled, Held 93-h 9.6 6.0 8.it 2.78 i.li* .1*2 .0i£ .01*9 6. Boiling Water 85.1+ U.7 5.8 — 1.68 — .33 .029 .051 Batch XVIII 1. Raw, Unpeeled 100.0 12.2 6.1 7.5 — — •61* .065 .060 2. Steamed 90.9 12.2 6.0 — — — .61 .059 .061 3* Boiled 90.9 9.7 5.9 8.8 — •1*1 .01*2 •01*9 I;# Steamed, Held 89.0 12.6 6.0 — — .62 .062 .061 3. Boiled, Held 95.2 9.1* 5.9 8.6 — — •37 .01*3 .01*7 6. Boiling Water 69.8 5.6 5.7 — — — .36 ?033 .052 Batch XIX 1* Raw, Unpeeled 100.0 12.8 6.3 8.1* 6.0 •9 .62 •066 • 061* 2* Steamed 91.0 12.7 6.2 — U.85 3.7 •59 .061; .061 5. Boiled 92.5 10.0 6.2 8.5 3.12 .81 •39 .039 .01*9 it* Steamed, Held 90.6 12.8 6.2 — 3*1*6 1.33 •59 .065 .061* 5* Boiled, Held "95.3 9.1 6.1 9.0 2.35 .65 .37 • 037 . .01*7 6. Boiling Water 92.8 1*.6 6.0 — 1.62 — •31 .028 .021 (Appendix) No. Description Batch Dry PH Caro- Asc. Acid Nia- Thia- Hibo- Wt. Wt. tene Tot. Red. cin rain flavir units % mg. /100 gm. Batch XX !• Raw, Unpeeled 100.0 12.5 6,3 8.9 6.1*2 • 58 .67 .066 .059 2. Steamed 90.0 12.7 6.1 — 14.69 •5U .62 .062 .060 3* Boiled 90.8 9.5 6.2 8.6 2.9U ,69 .U4 • 01+5 •ol*6 1*. Steamed, Held 90.2 12.9 6.1 — 3-77 1.0U .63 .065 .062 5. Boiled, Held 95.2 9.6 6.1 8.2 2.2 1.13 •39 .01+1+ .0J+5 6. Boiling Water 77.7 5.2 6.0 — 1.91* — .314 .033 .031 Batch XXI 1. Raw, Unpeeled 100,0 12.0 6.2 8.2 6.1; •U5 .61 .069 • 051+ 2. Steamed 91.2 12.1 6.3 — 3.77 .3 .36 .062 .057 3. Boiled 92.2 9.1 6.1 9.0 2*93 .1+8 .38 • 01+3 .050 1*. Steamed, Held 91.8 12.3 6.3 — 3-Sh .82 .61 .050 .05!+ 3. Boiled, Held 9U-7 8.8 6.1 8.7 2.09 1.13 •35 .01*0 .01*2 6. Boiling Water 83-5 U*9 5.9 — 1.95 — .32 .031 .026 Batch XXII 1. Raw, Unpeeled 100.0 12.7 6.2 8.6 6.33 • 58 .62 .067 .061* 2. Steamed 90.5 12.8 6.0 — U-53 .36 .65 .062 .066 3. Boiled 92.3 9.0 6.0 8.8 2.1+8 *kl .37 .035 .01+5 1*. Steamed, Held 90.2 12.5 5.9 — l*.l6 1.83 .61* .065 .061*. 5« Boiled, Held 95.3 8.7 6.0 8.2 2.2 1.01* • 38 .01*0 .01*8 6. Boiling Water 100.5 14-5 5-9 -- 1.6 — •31 .028 .030 Batch XXIII 1. Raw, Unpeeled 100.0 12.9 6.0 8.8 6.22 • 79 .61 .067 .061* 2. Steamed 91.3 12.7 5.9 — i+.e .77 .39 .063 .066 3. Boiled 9U.0 9*3 5.9 8.8 2.6 •714 .33 .039 .01*6 1*. Steamed, Held 91+.6 11.9 5.9 — 3.83 1.75 .53 .059 .062 5* Boiled, Held 96.9 9.2 5.9 7*3 2.*3 1.33 •33 .033 • 0i+5 6. Boiling Water e?.7 U.9 5-7 — 1.95 — .31 .028 .032 Batch XXIV 1. Raw, Unpeeled 100.0 12.6 6.1 8.1* 6.13 .93 • 37 .066 .037 2. Steamed 90.1* 12.6 6.1 — 1+.99 .71 .61 .O6.3 • .061 3* Boiled 92.7 9.2 6.0 8.7 3.14 .75 .36 .01*0 .01*6 1*. Steamed, Held 92.3 12.0 6.0 — it-31 1.68 .50 .058 .037 5* Boiled, Held 95.6 9.i+ 6.0 8.7 2.82 1.16 • 37 .059 .01*6 6* Boiling Water 71+.3 5.3 3.7 — 2.67 — — ,032 .032