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assumed intermediates to the actively fermenting culture, or studies with enzymes from the bacterial cell, might also prove exceedingly fruitful. The solvents formed in the fermentation of corn mash have been calculated to molar quantities and are given in Figure 7 . They appear in approximately the proportions: 1 mole C2H60H, 2 moles CH3COCH3, 3 moles CdHoOH. There are apparently no reasons per se why these molar relations should exist, and why they are so resistant to change. Perhaps if a better understanding of the mechanism of the fermentation were available, it would be possible to modify the proportions of the products as has been done in the production of glycerol by yeast.
LITERATURE CITED Bogin, C. D., IND. ENG.CHEM.,16, 380 (1924). Breed, R. S., and Brew, J. D., N e w York Bgr. Expt. Sta., Bull. 443 (1917). Donker, H. J. L., “Bijdrage tot de kennis der boterauur - , butylalcohol - en acetongistingen,” Thesis, W. D. Meinema, Delft (1926). Folin, O., and Wu, H., J . Bzol. Chem., 38, 81 (1919). Fulton, H. L., Peterson, W. H., and Fred, E. B., Centr. Baht. Parasitenk., I1 Abt. 67, 1 (1926). Gillespie, L. J., and Walters, E. H., J . Am. Chem. Soc., 39, 2027 (1917). Good&, L.‘F., Ibid., 42, 39 (1920). Harden, A., Thompson, J., and Young, W.J., Biochem. J., 5, 230 (1911).
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(9) Kluyver, 4.J., “The Chemical Activities of Micro-organisms,” pp. 41-53, Univ. London Press, London, 1931. (10) Marvel, C. S.,and Broderick, A. E., J . Am. Chem. Soc., 47, 3045 (1925). (11) McCoy, E., Fred, E. B., Peterson, W.H., and Hastings. - E. G., J . Infectious Diseases, 39, 457 (1926). 1121 Seubera. C.. and Arinstein. B.. Bzochem. 2.. 117. 269 (1921). (13) Peterson; W. H., Fred, E.‘ B.;and Domo$alla,’ B. P., J . ’ A m . Chem. Soc., 46, 2086 (1924). (14) Reilly, J., Hickenbottom, W.J., Henley, F. R., and Thaysen, A. C., Biochem. J . , 14, 229 (1920). (15) Schmidt, E. G., Peterson, W. H., and Fred, E. B., J . BioZ. Chem., 61, 163 (1924). (16) Schoen, M., “The Problem of Fermentation,” pp. 75-8, translated by H. Lloyd Hind, Chapman, 1928. (17) Shaffer, P. A . , and Hartmann, A. F., J . Bid. Chem., 45, 349 (1921). (18) Speakman, H. B., Ibid., 41, 319 (1920). (19) beakman. H. B.. Ibid.. 43. 401 (19201. (20j S&dunan; H. B.; Ibid,’,58,395’(1923). (21) Speakman, H. B., Ibid., 70, 135 (1926). (22) Stiles, H. R., Peterson, W.H., and Fred, E. B., Ihid., 84, 437 (1929). (23) Van der Lek, J. B., “Onderaoekingen over de butylalkoholgisting, “Thesis, IT. D. Meinema, Delft (1930). (24) Wilson, P. W., Peterson, W.H., and Fred, E. B., J . Bact., 19, 231 (1930). (25) Wilson, P. W., Peterson, W. H., and Fred, E. B., J . B i d . Chem., 74, 495 (1927). RECEIVED August 21, 1931. The work was supported i n part by a grant from the special research fund of the University of Wisconsin.
Tenderness of Meat Determination of Relative Tenderness of Chilled and Quick-Frozen Beef DONALD K. TRESSLER, CLARENCE BIRDSEYE, AND WILLIAM T. MURRAY, Birdseye Laboratories, Gloucester, Mass. UCH work on the relaTWO N O V E L i M E T H 0 D S for estimating t h e s a m p l e s . Chewing tests the relative tenderness of meat are were found t o be of value only tionshipof the connective-tissue content and when a wide difference in the One of these methods incolves the use of a n intenderness of the meat existed, the relative tenderness of meats has been done by Mitchell, zimstrument constructed f r o m a n ordinary tireA mechanical device for determining the shearing strength pressure gage. The other instrument is a modimerman, and Hamilton (9) and ped N e w York Testing Laboratory standard of meat (the so-called mouse by Mitchell, H a m i l t o n , a n d penetrometer. he relative tenderness various t r a p ) was developed in the Haines (1). While this work laboratory a t Beltsville by Baker m a y be of value in indicatcuts of beef of several grades is indicated. The and reported by Warner ing the age of the animal when slaughtered and the care given e$ect of quick-freezing on the teMhness of The work reported by LVarner and Baker is not a direct combeefsteak has also been determined and is preit prior t o slaughtering, the results c a n n o t b e c o n s i d e r e d sented in tabular form. These data indicate p a r i s o n of tough and tender absolute. It is a g e n e r a l l y that after meat has been stored f o r meats but is a study of the correl a t i on b e t ween the breaking recognized fact that pounding one week, it is approximately 20 per cent more strength of the meat muscles or hammering t e n d e r s m e a t . Many persons i n s t r u c t t h e knder than before freezing* of the left and right side of a given animal and a similar combutcherselling the meat to hammer their steaks immediately after cutting. Some cooks always parison of the shearing strength of raw and cooked meat. As yet the results obtained by the devices described in this hammer the meat just prior to cooking. The hammering of the meat changes it physically so that it is more easily masti- paper have not been compared with those which may be cated, but this probably has little chemical effect on it. It is obtained by means of their apparatus for determining the doubtful that a determination of the amounts of collagen shearing or breaking strength of meat, but this will be done and elastin in the muscle tissue, as carried out by hlitchell and and reported in a later article. It is often stated that the quick-freezing of meat noticeably his co-workers, would indicate any change in the meat because tenders it, but no one has carried out chemical or physical of the hammering process. Preliminary comparative tests of the eating qualities of tests to prove the point. In this case it is very unlikely that samples of meat were unsatisfactory because of the inability any chemical method could be developed which would indit o obtain in some cases an agreement of the testers concerning cate changes in tenderness in the meat during freezing. No the relative tenderness of any particular sample. Moreover, one has as yet demonstrated exactly how quick-freezing of difficulties were encountered in obtaining uniform cooking of meat tenders it, but certain investigators have postulated that
Februury, 1912
I R D Cl S T 1% I A I. A N D E: N G I N E E 11 1 N C. C H E M I S T H Y
this effect is caused by the stret,cliing of tlie partially froaeir conneatirc tissue during tire exparrsim~ of tlre meat on freezing. Such a change is a physical phenomenon not determinable chemically. Therefore, when a study
