Correction. Quantitative Determination of Ergosterol, Cholesterol, and

(19) Rubin, S. H., DeRitter, E., Schuman, R. L.,and Bauernfeind,. J. C., Ibid., 17, 136 (1945). 20) Schweigert, B. S., Mclntire, J. M., and Elvehjem, ...
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Table

Sample No. Chuck 10 11

12 13 Heel-of-round 1

3 4

301

ANALYTICAL EDITION

May, 1946

VIII. Riboflavin Retentions in Braised Beef

Based on Total Fat-Free Dry Weights Total Roast Drippings MicroMicroMicroFluorobioFluorobioFluorobiametric logical metric logical metric logical

%

a

%

%

76 79 63 72

77 79 63 73

33

78 80

78 81 81

26 39

*.

34

35 29

..

%

.

%

~

Based on Total Moist Weight MicroFluorobiometric logical

%

%

% 113 114 99

36 37 34 30

110 114 96 101

112 116 97 103

111

26 41 26

104 119

104 122 107

99 115

...

McIntire et al. (10) report retentions of 106 and 105T0 in one sample each of veal stew and lamb stew and also ( l a ) 108 and 109% in one sample each of broiled and braised beef liyer including drippings, and Rice and Robinson (17) 10770 in one sample of pork precooked for dehydration. These retentions were all based on total moist weights. Since, however, those reported by the first group are the exceptions rather than the rule, they could be considered to result from a combination of assay errors. Basing retention calculations on riboflavin values per gram of protein, the latter aubhors also report 109% for beef precooked for dehydration and 105’% in the dehydrated beef, whereas Schweigert et al. (21)obtain 106 and 10870 retentions in 2 out of 4 hams carried through the curing process. Rice and Robinson attribute their high retentions to the formation of stimulating substances (to L. casei) during cooking, whereas Schweigert et al. conclude that the best method of chlculating the per cent of vitamin retention is on the basis of original and final weights of the samples tested because i t is the most direct method. One wonders how much this conclusion was influenced by the fact that the alternative method of calculation, based on protein, brought these two riboflavin retentions and one niacin retention above 105%. I n the experiments here reported there was no indication of the presence of stimulatory material in the cooked samples, such as drift in microbiological assays. Standard recovery tests were also run with each microbiological assay and gave uniformly good results-96 to 98%. Moreover, one preliminary comparison of assays done with and without ether extraction of the filtrates from all three types of samples showed no alteration of values for any of them after ether extraction,

A recent report by Feaqter et zl. (6) shows that the phenomenon of increased riboflavin as determined by microbiological assay also occurs during storage of processed pork. High retentions similar to those determined on beef have aho been obtained in this laboratory in some cooking of vegetables assayed by the same fluorometric method.

112 98 92

...

95

preparation of extracts, nor by digesting with Clarase in preparation for chemical assay, and also of such a nature that without release it is unavailable to microorganisms. Long cooking as compared to short cooking should be further investigated and perhaps the possibility of an enzymic action in the tissue itself during a slow rise in temperature should be considered.

98 114 106

ACKNOWLEDGMENT

Grateful acknowledgment is made t o B. 8. Schweigert and Mrs. Pollard of the Department of Biochemistry, University of Wisconsin, for their riboflavin values included in Table IV of this paper. LITERATURE CITED

Andrews, J. S.,Cereal Chem., 20, 3 (1943). (2) Andrews, J. S., Boyd, H. M., and Terry, D. E., IND.ENG.CHEM., ANAL.ED., 14, 271 (1942). (3) Brush, M. K., Hinman, W. F., and Halliday, E. G., J . Nutrition, (1)

28, 136 (1944). (4)

Conner, R. T., and Straub, G. J., IND.ENG.CHEM.,ANAL.ED., 13,385 (1941).

( 5 ) Cover, S., McLaren, B. A,, and Pearson, P. B., J . Nutration, 27, 363 (1944).

(6) Feaster, J. F., Jackson, J. M., Greenwood, D. A., and Kraybill,

H. R., IND.ENQ.CHEM.,38, 87 (1946). (7) Ferrebee, J. R., J . Clin. Investigetion, 19, 251 (1940). (8) Hodson, A. Z., and Korris, L. C . , J . Bid. Chem., 131,621 (1939). (9) Kahler, H., and Davis, E. F., Proc. SOC.Exptl. B i d . M e d . , 44, 604 (1940). (10)

McIntire, J. M.. Schweiaert. B. S.. and Elvehjem. C. A.. J. Nutrition. 26. 621 (1943). .

McIntire, J. M., Schweigert, B. S., Henderaon, L. M., and Elvehjem, C. A., Ibid., 25, 143 (1943). McIntire, J. M., Schweigert, B. S.,Herbst, E. J., and Elvehjem, C. A., Ibid., 28, 35 (1944). McLaren, B. A., Cover, S.,and Pearson, P. B., Arch. Biochem.. 4, 1 (1944).

Meyer, B.. Hinman, W. F., and Halliday, E. G., manuscript to be published by Food Resea~ch. Najjar, V. A., J . BioZ. Chem., 141, 353 (1941). Peterson, W. J., Brady, D. E., and Shaw, A. D., IND.EXQ. CHEM.,Ari.4~. ED., 15, 634 (1943). Rice, E. E., and Robinson, H. E., Food Research, 9, 2 (1944). Rosner, L., Lerner, E., and Cannon, H. J., IXD.ENQ.CHEM.. ANAL.ED., 17,778 (1945). Rubin, S. H., DeRitter, E., Schuman, R. L., and Bauernfeind, J. C., Ibid., 17, 136 (1945). Schweigert, B. S., McIntire, J. M., and Elvehjem, C. A , , J . AVutrition, 26, 73 (1943). Ibid., 27, 419 (1944). Smith, H. S.,dissertation for degree of master of science, University of Chicago, 1944. Streightoff, F., Munsell, H. E., Ben-Dor, B., Orr, M. L., Leonard, M. H., Ezekiel, S. R., and Koch, F. G., J . Am. Diet., Assoc., June, 1946. Strong, F. M., and Carpenter, L. E., IND.EXG.CHEM.,ANAL.

Weinberger (26) reported 7 out of 13 determinations of retentions with several household methods of cooking cauliflower which fell bet-iveen 109 and 129%, and 4 out of 10 on broccoli between 107 and 121%. Smith (22) has reported a few such high retentions in institutional boiling of carrots and green beans as well as in small-scale boiling of the latter. Another laboratory has likewise obtained such results on carrots using the microbiological method. Streightoff et al. (23) report an average riboflavin retention totaling 1227, for boiled carrots plus boiling water in ten batches of stored miscellaneous varieties and of 112% in ten batches of fresh Chantenay Coreless carrots, during large quantity preparation. Thc senior author stated (personal communication), moreover, that the “data on riboflavin were very consistent” which must mean that a large majority of individual cooking experiments gave retentions above l l O % , and added that they obtained “much the same sort of result in the case of cabbage”.

Tms investigation was supported in part by the National Livo Btock snd Meat Board.

I n the light of all the above investigations it would seem that the probability of the liberation of riboflavin from a precursor or complex in certain types of cooking procedures must be given consideration. Moreover, since chemical and microbiological assays yield similar results, i t would be necessary to postulate that the complex from which riboflavin is formed or released during cooking is of such a nature that the vitamin cannot be liberated by digesting or autoclaving under acid conditions as during the

I n the article entitled “Quantitative Determination of Ergo6 terol, Cholesterol, and 7-Dehydrocholesterol” by Lamb, Mueller, and Beach [ IND.ENG.CHEM.,ANAL.ED.,18, 190 (1946) ] an error was made in Table IV, where the antimony trichloride value on yeast sample 3 should have been 2.41.

ED., 14, 909 (1942). Tucker, R. E., Hinman, W.F., and Halliday, E. G., manuwript in preparation. Weinberger, R., dissertation for degree of master of science, University of Chicago, 1943. Wright, B., and Booth, R. C.,Biochem. J., 37, 25 (1943).

Correction