April, 1933
INDUSTRIAL AXD ESGINEERING CHEMISTRY
sulfates. It is common knowledge that excessive manuring results in the production of poor beets. It is also well estabblished that soils which are high in available nitrogen also produce poor beets. These and other observations lead to the conclusion that excessive soil nitrates, whether from manure or other sources, are capable of stimulating the assimilation of inorganic elements, especially sodium and chlorine, to such an extent that the purity and sugar content of the beets are adversely affected. Or in more specific terms, excessive nitrates tend to retard the elaboration of sugar and to increase the ratio of soluble to insoluble nonsugars. The hereditary characteristics of the beets also influence the amount of the various inorganic elements which will be taken from any given soil under the same growing conditions. Individual beets from a pure bred strain showing a variation of only 10 per cent in the sugar content will vary as much as 400 per cent in chlorine and 50 per cent in calcium and magnesium. The average composition of ash of different strains grown side by side shows variations of over 400 per cent in chlorine; the sugar and purity vary less than 5 per cent,
465
It is obvious, therefore, that variations in the quality of beets are the result of a combination of many complex factors, but that on the average these variations follow certain welldefined rules with respect to the relation between sugar content and purity and the amount and composition of the ash CONCLUSIONS It has been shown that the amount and composition of the inorganic constituents of sugar beets bear a definite relation to their purity and sugar content. The ash (percentage on dry matter) or the calcium and magnesium content of the ash are the components which serve as the more reliable index to the quality of beets. The presence of excessive amounts of nitrates in the soil is detrimental, since they stimulate the assimilation of certain undesirable soil elements, especially sodium and chlorine, and thereby increase the ratio of soluble to insoluble nonsugars. RECEIVEDSeptember 10, 1932 Presented before t h e Division of S u g a r Chemistry a t the 84th Meeting of t h e 4meriran Chemlcal Soriety, Denver, Colo , August 22 t o 26, 1932
Effect of Storage on Vitamin A in Dried Foods G. S. FRAPS AND RAYTREICHLER, Agricultural and Mechanical College of Texas, College Station, Texas
T
HE recognition of the importance of vitamin A in
human and animal nutrition has increased the commercial importance of some foods or feeds known to be good sources of vitamin A. Alfalfa meal, alfalfa leaf meal, yellow corn, and some other feeds are used by feeders and by manufacturers of commercial feeds, partly for the purpose of supplying vitamin A. Preference is given to certain human foods on account of their high content of vitamin A. The effect of storage on vitamin A thus becomes of industrial as well as of agricultural importance. Information regarding the effect of storage upon vitamin A in foods is limited and somewhat contradictory It is generally accepted (6) that cod liver oil or vitamin A concentrates, when mixed with ground foods as in a poultry mash, loses its vitamin A in a comparatively short time. The vitamin A naturally present in foods is considered to be more stable, but definite information is limited.
PREVIOUS WORK Jones, Murphy, and Moeller (3) claimed that there was no appreciable destruction of vitamin A in eggs when they are stored in the frozen condition over a period of 9 years. Tso (8)announced that Chinese preserved duck eggs are as rich in vitamin A as fresh duck eggs. Manville (4)states that eggs kept in cold storage a year lost 75 per cent of their vitamin A, and that those kept in water glass lost 50 per cent in 18 months. Morgan and Field (6) claim no decrease occurred in the vitamin A content of both sulfured and unsulfured apricots and prunes stored a t 0" C. for a period of more than a year. Rethke and Kick (1) report there was little deterioration in the vitamin A content of yellow corn stored for one year, either whole, cracked, or finely ground, and that the vitamin A content of dried alfalfa hay was not influenced materially by storing for one year, either ground or unground. Quinn et al. (7) &ate that the loss of vitamin A in dried spinach amounted to approximately 70 per cent upon storage
for a period of 12 to 15 months. Von Wendt (9) reports that the vitamin A content of food diminishes during the winter months, that the vitamin A is slowly oxidized xhen foods are stored, and that cattle fodder, such as hay and carrots, becomes markedly deficient as a source of vitamin A as the winter months progress; hence milk and other dairy products also become deficient in vitamin A.
VITAMINA TESTS The material (all finely ground except some unground samples of corn) was stored a t room temperature in maPon jars. All samples were exposed to the diffused light of the laboratory and remained tightly closed except while portions were being removed for feeding. With the unground corn, just enough was removed and ground to feed the rats from 2 to 3 weeks. Units of vitamin A were determined by the ShermanMunsell method as used in this laboratory ( 2 ) . A unit of vitamin A is taken to be the amount sufficient to produce a growth of 24 grams in 8 weeks on rats previously depleted of vitamin A. As it is difficult to secure exactly this growth, the units were in some cases estimated from different gains on the basis of experience with the test animals. The rats were continued on a ration deficient in vitamin A for 28 days; then they were weighed every other day until their weight remained constant for 6 days or until a loss in weight occurred. At this point six or more rats were fed weighed amounts of the feed to be tested for 8 weeks. Usually they were fed daily, except Sundays, but, in some cases where the feed was high in vitamin A, they were fed twice a week. Average details of the tests are given in Table I with the estimated units of vitamin A found a t the various periods, and the approximate percentages of the original vitamin A which were lost on storage. The data show clearly a loss of vitamin A during storage of alfalfa leaf meal, dried black-eyed peas, dried green sweet pepper, p,owdered whole milk, and yellow corn, either in the whole grain or in the meal.
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The loss of vitaniin A of alfdfa leaf meal may be 50 per cent of that originally present after 11 months, 50 per cent of that in dried black-eyed peas after 9 months, 80 per cent of that in dried green sweet peppers in 19 months, 60 per cent of t.hat in powdered whole milk in 9 months, and about 50 per cent in whole or ground yellow corn in 6 months. These are appreciable losses of vitamin A, and the periods of storage are not longer than may ordinarily occur. Grains and hay must necessarily be stored from one hwvest period to the other. During the storage there is evidently an appreciable loss of vitamin A. The quantity of vitamin A found by experiment on a particular feed will depend to some extent on the period of time the feed has been stored. Yellow corn wliich contains
Tsris ANTERACITE& ~ A X E R I s
TEE
C 1%13 M I S T R Y
Vol. 25, No. 4
six iinits of vitamin A to the grain new tile time of harvest may contain only three units to the gram F months later. The same consideration applies to other feeds stored in a dried condition. These feeds were stored at ordinary morn temperature, which is somewhat high in Texas during the summer rrionths. It ii. possible that there would be less loss of vitamin A if the goods were stored in a cooler elimat,e or in cold storage.
SUXMAKY There i8 a gradual loss during storage in the vitariii~iA content of alfalfa leaf meal, dried black-eyed pcas, dried green sweet peppem, yellow corn, and powdered whole inilk. Men,siired by the Shermaii-;llunselI unit method, nlfalfa leaf meal lost about 50 per cent of its vitamin A in 11 months, dried black-eyed peas 54 per cent in 9 montlrs, dried g e e n sweet, peppers 80 per cent in 19 months, powdered whole milk 60 per cent in 9 months, and yellow corn 30 to 60 per cent i n 6 months. The loss of vitamin A in dried samples stored in the Iaboratory should be taken into consideration in experimental work. It is possible that the loss mould be less for goods stored in a cooler climate or in cold storage. The loss of vitainin A in stored feed may be a factor of considerable importance in connection with the feeding of animals or man. The amount of destruction of vit.amin A varies both wit.lr the length of the storago period and the kind of material containing the vitamin. Grinding corn before storage does nut seem to increase to any noticeable degree the loss of the vitamin A in ydlow corn as coinpared with the whole grain.
LITERATTIKG CITED (1) Bethke. 1%.M..and Kick. C. 15.. Ohio Erot. Sls. Ann. Rent.. . . Buii. 431, 117 (19211). (2) Raps, G. S.. Tox. Agr. Crpt,. Sta.. Uiiii. 422 (1931). ("1 Jones, Morphy. :aid Mloeller, A m . J . Phvnioi., 71, 266 (l!vzJj. (1) Manuille, Am. J . Hjm.. 6, 238 (lo%). ( 5 ) Mnttili. IT. A., J . A m Ilcd. . ~ S S O C . . 89, 1506 (I!Ui), ( 6 ) Moig:m and I'ioid. J . Bioi. Cl~em..88,$1 (19:W). I. f i d, . , 89, 0;i7 (7) 13. .J.. r m i e y . ,I. G., and Dorow. &I. .I (1930). ( 8 ) Tso. E., Proc. SOC.U.rpl/. Bioi. W e d . , 22, 263 (1924); E.ipl. Sla. Record, 53, 459 (l!L?sj. ( ! I ) Wendt, G. "On, min. Wochsdr.. 4, 2389-00 (1923).
wnn,
Rncr;ivr;o SepLeiebcr 10. 1032.
Presented before t h e Division of .i&iioul-
third and Food Ciicniatry iLt the 84th &sleeting crf the American Chemical Soricty. Denver, Cdo.. Auguat 22 to 28, 1982.
LARGEST Co.~r,-WnnmucPLANTIN TIlE WonLn. COAL-LADEN Wnsa WATER DoRn TRACTION 'rnlCKENER
FROM lT F L O W S TO A SSO-FOUT
