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I X D U S T R I A L Ah-D ENGINEERIXG CHEMISTRY
Since most commercial sands contain more material in the 50- to 30-mesh range than is needed for high-grade work, it is suggested that the addition of sound, finely crushed rock will of uniform grading for the lower part of the frequently be economically justified. The upper part of the curve might often be improved by adding more coarse aggregate. Admixtures are helpful in so far as they bring any part of the whole sand-cement system closer to the ideal.
VOl. 23, Yo. 9
Literature Cited (1) American Concrete Inst., PYOC. Am. Concrele ~ n s i . ,26, 361 ( 1 9 2 9 ) ~26, 36, footnote (1930). (2) -4merican Concrete Inst, I b i d . , 2% 550 (1929). (3) Anderegg, I b i d , 26, 334 (1929). (4) Burks, I b i d . , 1, N ~ 4,315-58 . (1930). (5) Fuller and Thompson, Proc. Am. SOC. CWI E n g , 33, 222 (1907). (6) Furnas, IND.ENG.CHEM.,23, 1062 (1931). (7) Graf, Ber. deut. Befon-veY., 31, 117-39 (1928). (8) Hill, Rock Products, 23, No. 24, 122-3 (1929). (9) Talbot and Richart, Univ. Illinois Eng. Expt. Sta., Bull. 137 (1923)
Vitamins in Canned Foods XI-A Canned Food Diet’ E. F. Kohman, W. H. Eddy, and Celia Zall Gurin RESEARCHLABORATORIES, NATIONAL CANNERS
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ASSOCIATION, &‘ASHINOTON,
N A series of studies (2) pertaining to the vitamin content of canned foods, it has been found that each of the vitamins, A, BI, Bz,and C, may be supplied in adequate
amounts by various canned foods. This has been demonstrated in experiments in which a given canned food was required to be the sole source of one or another of the vitamins. The experimental period of these investigations has been the usual period prescribed for the various vitamin tests-that is, 60 days for vitamins A and B and 90 days for vitamin C. The experiments were directed p r i m a r i l y to the study of the stability of the v i t a m i n s to the c a n n i n g process. Tests for vitamin D c o n t e n t h a v e not been made because this vitamin has been shown to be stable to processes similar to those employed in canning, and because the vitamin D content of such foods as were tested is generally stated to be small. It is generally accepted that nutritional deficiencies not in evidence in one generation may manifest themselves in subsequent generations. It w a s t h e r e f o r e Chart 1-Average Growth Curves deemed of interest to feed of R a t s test animalson canned foods as the sole diet over a longer period than is covered by the classical vitamin test periods in order to determine the effect on offspring and longevity. The experiments instituted for this purpose and reported here to date are limited to white rats and guinea pigs. The plan of experimentation is to feed a variety of four or five canned foods chosen with a view to securing a balanced diet for a period of 5 days. These foods are not mixed, and the animals are allowed to eat according to their own choice. The animals receive no irradiation treatment, nor are they exposed to the direct rays of the sun. At the end of each five days, a change is made to form a new combination of canned foods. Thus far forty-nine canned foods have been fed in seventy-four combinations, the plan being 1 Received May 7, 1931. Presented before the Division of Biological Chemistry at the 81st Meeting of the American Chemical Society, Indianapolis. Ind.. March 30 to April 3, 1931.
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c.,A N D TEACHERS COLLEGE. COLUMBIA UNIVERSITY, NEWYORK,N.
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to repeat the combinations after all of the common canned foods have been utilized. The purpose is not to study any particular food or group of foods, but rather to determine the nutritional adequacy of canned foods. The canned foods are purchased at grocery stores just as they would be purchased for home use. The foods used, therefore, represent those available to everyone. Observations with Rats and Guinea Pigs
In beginning this experiment, three pairs of rats, 28 days old, were placed on the canned food diet. The weight of the females ranged from 53 to 55 grams and the males from 55 to 56 grams. Three pairs of guinea pigs were also placed on a similar diet. As these had to be purchased, their age is unknown, but the weight of the females varied from 330 to 395 grams and the males from 320 to 430 grams. Later a fourth pair of guinea pigs, 3 weeks old, was added, the female weighing 130 grams and the male, 135 grams. The experiment with rats has now been in progress for 15 months and the experiment with guinea pigs for 13 months. As these animals give birth to young, a male and female from each pair are bred r e spec t i v e l y with a female and m a l e of a n o t h e r p a i r , a n d in t h i s manner succeeding generations are ottained. A record of the number and size of l i t t e r s is k e p t . After the r e q u i r e d number for breeding purposes is selected, the extra young are Chart 2-Average Growth Curves of Guinea Pigs discarded at weaning time. and data on-growth and longevity are kept only on the animals necessary to continue the experiment with a constant number of pairs. The rats have reached the fifth generation and the guinea pigs the third. Each generation is thriving apparently as well as these species of animals thrive under any conditions. Reproduction is as prolific as can be expected, the size of the litters is normal, lactation is adequate, and the young are making growths equal to that of the parents. The effect of longevity remains to be determined.
:INEERI.K(: CHEMISl'RY
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pcriinents Inxy benefit by tlie softer texture of a cooked diet, although cooked foods are foreign to their natural mode of living. In regard to ail adequate suppiy of vitamins i t should be not.ed that a number of the foods eat,en only in the cooked form are the richest sources of certain of the vitamins, particularly vitamins A and C . As has already been brought out, vitamin A is unaffecteil by the canning processes, and although then: may be some destruction of vitamin C , many of the suceolcnt vegetables (particularly those of grccii color) that have vitamin C in very high concentration in the raw state are, after canning, still very potent sources oi the antiscorbutic f a c t o r . As most of Chsrr 3 Individual Growth on Reproductive Curves of Second Generalion of Guinos P(SBFed on Cansled Boc~ds
Hy tlie end of one year, the feniale rats haso at.taiiied wights varying from 305 to 330 grams; the male rats, 485 to 56U grams; tlie feniale guinea pigs, 783 to 1360 grams; and the male guinea pigs, 1025 to 1225 grams. The weight recorded as normal by Donaldsoii ( I ) for female rats a t the end of oiie year is about 225 grams and for male rats about 300 grams. There is on record no standard weight for guiiiea pigs comparable to tlie standard on rats published by Donaldson. Howevcr, the rate of growth on guinea pigs on an exclusive canned food diet is as rapid as the authors have encountered undcr m y conditions, and the weight reached after one year is coiisiderahly above what is ordinarily regarded as norinal for guinea pigs. 'The use of raw Soods in tlie diet is frequently advocated so strongly as to give the inipression that a certain amount of raw foods is a necessity. This advice is most comnionly associatcd with discussions of vitamin C . The practice of cooking Soods antedates history, and it is a practice with which civilization can ill afford to dispense. Furthermore, there is no record that the culinary ad has had adverse consequences. The experirncnts herc reported have gone far beyond the itsid test for the vitamins, and thus far there is certainly no evidence that cooked foods, as represented by canned foods, are incapable of supplying all of the vitamins nr other nutritional requirements in adequate quantities. The rapid rate of growth and the maturity weight attained deserve Snrtlrer att.erition. Either thcse experimental animals have bcSore them a more nearly optimum diet for growtli and maturit,y weight than is usual, or there is some heretofore nnrecognized advantage in the diet inado up wholly of cooked foods as represented !,y canned foods. It is possible that t I)orou g l i ly cooked foods are more e a d y digested a n d more highly assinrilated, m a k i n g possible n more efficient utilizntion. T h e desirability of thoroughly cooking foods for iiiFigure I Mother and Utter of 22fallts i s well recogUay-Old Guinea Pins Reared Entirely on nized. T h e medical Canned ~~d~ profession has recently been ninpiratic in discussing tlie harm that may be done by too great a consumption of coarse roughage. As a matter of fact, t i m e is a considnrnble Seeling against the tenn roughage, as volun~e,bulk, or indigestible residue are more accurately descriptive of the dietary qualities in question. Cooking softens the texture of tlie fibrous material that constitutes the indigestible residue. In view of this, it is not unreasonable to a5siime that tlie two species o i animals in these ex~
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added that a sr:rving Finure 2 .-Third Grnerafion of Guinea Pigs on Canned Food Diet raw vegotahie Lelt toright, 78md86daysuid,re.pe;tiupiy is eonerallv much siri&r than serving of the same vegetable when cooked. Certain details of the reactiori of these animals to a canned Sood diet 81% recorded in the accompanying charts. in Chart 1 the growth curves A and R are those published by Donaldson ( I ) as representing tlie normal for the rat. The animals reprcsentod by A are said t,o have been fed on sclected table scraps. Graphs A A are the average of t h e e feinale and three male rats placed on a canned food diet when 28 days old. The numhers on the graphs representing the females are the number per litter of young. Superimposed 011 graph A A is another, 0 and M , representing the maximum rate of growth for male rats obtained by Osborne and Mendel (3). Graphs RH represent tlrc average for three females and three males, and are the progeny of the animals represented by graplis A A . Graphs CC represent the average for two females and two males that are progeny of the animals represented by graphs BR. Graph DD represents the record of the one iemale of the fourth generation that has rcached reproductive ace. It is to be noted Of
s
diet' It Fiqure 3 Rats 90 Days Old Fed 0x1 is to be noted also Canned Foodsrrom~irneoi Birth Mother &u reared en canned food that succeedine eene r a t i o n s of Fats nrake its good growth as the first generation Sed on canned I
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00 Chart 2 is recorded the average growth curve of four male and of four to five female guinea pigs over the course of a year. These animals were placed on a canned food diet when their weight varied from 320 to 430 grams. ?lie numbers on the graph Rpresenting the feinales are the number of young per litter. One female died in parturition as indicated by an asterisk. The graphs on Chart 3 represent the growtlr and reproductions of guinea pigs that have had only canned foods from time of birth, except for tlie milk of their mothers that subsisM on canned foods alone. They are the progeny of the animals represented by Chart 2. The R series represent the
Piwre 4 - ~ o t h e r n n d 28-Day-OldLittrr Repro~enfineThird m d Fuurfli Cenera;iona of R~~~ ped On cnnned ~~~d~ Only
seeo1,d a n d t h e L' series tlie t!iirdgeneration 011 a canned food (liet,. Tlic iiurnhers 011 t h e g r a p h s rcpresentiiig t h e fcmalcs are tlie numh e r per 1itt.er of young. Figures 1 to 4 are pliotograplis of typiea1 animals 011 a diet
made iip exclusively uf canired foruds. Summary
Three pairs of young guinea pigs, nreighiiig Sroin 320 to 430 grams, and one pair 3 weeks of age, and three pairs CJf young rats, 25 days of age, weighing from 53 to 56 grains, were placed on a diet consisting wholly of canned foods sterilized By beat. The plan is to feed such animals a similar diet ovcr a iiumher of generations. The foods are not irrt~liabeilnor do the animals recrivc irradiation nor direct ra3-s of the sun. Tho ex-
perimeiit has h e n in progress about 15 rirontlis. During this time, tiic aniinals wen: mated and bred so tliat irr a little over a year tlie fifth gcncration of rats ani! tlie tliirrl gcnerat.ion of giiirioa pigs was seaoiied. 'l'liey are thriving as well as is indicatcd by any record of tliese species. Ilcproduction is as prolific as can be expected, tlic size of tlic litters is iiomial in every way, and 110 difficulty is encountered io lactatiori. Tlie rate of growth and wsight at maturity is inrich liiglm than that reported anornial. In erplaimtioii of this, it is suggestcd that either a diet more nearly tlic optimurn than usual for these species results from tire combination of foods selected, or tliere is some heretofore unrecognized advantage in a diet made up wholly of camied (cooked) foods. Tire i??ridcnccindicates that canncd foods inay supply every dietary requirement, including vitamins 13 (Bi) aiid C, so often referred to as heat labile. Literature Cited (1) Dunridson. "The Rat," Memoirs Wisini I n t . Anal. and Bioi., No. 6 , Philidclphia. 1924. (2) Eddy, Kohmae. et %I., IN". EN*. C n o x , 16, 52 (19241: 15, 1261 (1924): 1'7, 69 (1'325); IS, 85 (1926); IS, 302 (19261: 10. 202 (iwn); ai, 347 (1929); 81,869 (1929) ?a, 1015 ( 1 8 s ~ ( 3 ) Osboineand Mendel, J . Bioi. Chrm., 69, 6 6 1 (19261. ~
Salmon Oil and Canned Salmon as Sources of Vitamins A and I>' C. D. Tolle and E. M. Nelson Bmsnu
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P i s s n w s s , DBPAXIMINT OB COMMKRCB, A N D BUREA" OP C H ~ M Z S T A PNYD SOILS.DUPABTU~NT us ACRICULIURB.W ~ s s i n a r o a .D. C
HE present anmial proCommercial salmon oil is an important source of salmon offal, oil from canned duction of salmon oil vitamin D, but the commercial oil now produced is s a l m o n , and c o m ~ n o r c i a l in tjris coiilrtryis apnot representative in quality of the oil that can be salmon oils. proximately 300,000 galI(jns produced from the standpoint of potency of vitamins Sources of Materials (11). However, the quantity A and D. The oil now produced is used largely for of oil that can he produced technical purpo=s3 and the annual production is Samples of commercial oil approximately 3O0,OOO gallons. This quantify can be were obtained fromoilsavailgreatly exceeds this figure. There are about 500,000,000 increased threefold by using products which are now able on the market. Samples discarded. The canned salmon consumed in this of oil were prepared from the pounds of salmon c a u g h t annually in the United States country carries a vast supply of vitamin D that has canned offal of five species of and Alaska. of wlrich 25 to 30 hitherto received little, if any, recognition. s a l m o n . The offal was obtained from fresh fish, placed per cent becomes waste when the fisli is canned. The waste will yield 15 to 20 gallons of oil in tin cans. Tlie cans were evacuated and then heated in a per ton, which makes the potential production of salmon oil retort for 5 hoursat 212'F. (100'C.). When thecans arrived at the laboratory they were opened, the coiltents transferred about 1,000,000 gallons annually. In a study of the vitamin content of commercial fish oils, to a hand press and the water and oil expressed. The oil wm Nelson and Manning (8) found that a salmon oil was 50 then separated from tlie water arid suspended material, by per cent as potent in vitamin U as a medicinal cod-liver oil centrifuging. Commeri:ially canned salmon of fiw different aiid that, its vitamin A content was equal to the poorer grades species were obtained from packers. The oil was recovered of iiiedicinal cod-liver oil. Other investigations liave prc- in the same manner as from the salmon offal. viously shown that oil from salmori contains vitamins A For a number of years cod-liver oil has been a recogiriaed and D ( I , 3,5). Manning, Nclson, and Tolle (8) found that source of vitamins A and D. Examination of t,hirty-seven the vitamin U content of menhaden fish oil is irifluerrced samples of medidnal cod-liver oil, for the Food and Drug in part by t!ie heat treatment to which the oil is subjected Administration, United States Department of Agriculture,* in the process of production. Because of the large potential has shown tlrat only two of these oils varied more than 25 production of salmon oil arid the possibility of improving per cent in vitamin 11 potency from one of the samples the quality of the oil by proper production methods, this chosen as a staiidard of reference. Some of these oils were product has been studied further. The studies herein re- found t,o be fully six times as potent as others in vitamin A. ported were designed to obtain further information wit11 The cod-liver oil used for comparison in t h e studies aas respect. to tlie vitamin content of oil prepared carefully from representative of the average medicinal cod-liver oil in vitamin U potency and considerably above the average in vitamin Presenicd l>eloorrthe Division of Biulopical Received June 1, 1931 A potency. Cheminfiy at the 81% Meeting oi the Ameiiesn Chemical Society, Indian-
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spoiis. Ind..
March 30 t o April 3, 1931.
8
Nelson, E. M., unpublished data.
