LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF CHEMISTRY, Washington, D. C., May 18, 1908. SIR: I submit herewith for your consideration and approval the manuscript of a preliminary report on the changes in food products kept in storage, especially at low temperatures. These investigations have been carried on in harmony with the will of Congress as specifically expressed in the several appropriation bills of the last few years. The objects of the studies are fully stated in the introduction to the present report, now offered for publication as Bulletin 115 of the Bureau of Chemistry. Respectfully, Hon. JAMES WILSON, Secretary of Agriculture. H. W. WILEY, Chief of Bureau. 3 Chemical changes produced by bacteria at low temperatures Effect of low temperatures on enzymes ........ The action on flesh of bacteria and enzymes at low temperatures. Discussion of results obtained in the Bureau of Chemistry... ILLUSTRATIONS. PLATE I. Fig. 1.—Outer shell membrane of fresh egg. Fig. 2.-Inner shell II. Fig. 1.-Yellow yolk of fresh egg. Fig. 2.-White yolk of fresh egg IV. Chicken after storage at 13° F. from December 24, 1903, to February V. Chicken, massaged and made as flexible as possible, without soaking, VI. Normal chicken muscle. Fig. 1.-Longitudinal section. Fig. 2. 80 Transverse section VII. Breast muscle of chicken in cold storage fourteen months. Fig. 1.- Fig. 2.-Transverse section .... Fig. 1.-Longitudinal section. Fig. 2.-Transverse section... XI. Breast muscle of chicken in cold storage four years. Fig. 1.--Longi- XII. Small intestine of fresh chicken XIII. Small intestine of chicken six months in cold storage 84 86 86 7 8888 |