54° 



Journal of Agricultural Research 



Vol. VI, No. 14 



Acidity was determined by titrating 50 c. c. of the filtered extract 

 against standard sodium-hydroxid solution, using phenolphthalein as an 

 indicator. The results are calculated in terms of lactic acid. 



Total creatinin' was determined according to the method of Folin 

 as modified by Emmett and Grindley (1, p. 515). The results are 

 calculated in terms of creatinin. 



Free creatinin was determined essentially according to the method of 

 Folin (2). Standard creatinin solutions were made from creatinin which 

 had been standardized against NJ2 potassium bichromate. With close 

 attention to all details this method was found to give very satisfactory 

 results. 



Table I shows the changes in the creatin and creatinin content of lean 

 beef autolyzed under aseptic conditions for periods ranging from 7 to 

 100 days. 



Table L- 



-Changes in creatin and creatinin content of muscle during aseptic autolysis 

 at 37° C. 



109. 

 no. 

 in. 

 112. 



"3- 



120. 

 121. 

 122. 

 124. 

 125. 



Serial No. 



Incubation 

 period. 



Days. 



7 



14 

 21 

 28 

 42 

 64 

 77 

 93 

 100 



Percentage 



of acid as 



lactic. 



3- J 5 

 3-°3 

 3-i5 



3. 16 



4-75 

 4-33 

 4-53 

 5. 02 



4- 74 



4. 76 



Percentage 



of total 

 creatinin. 



i-73 

 1.97 

 1. 91 

 1. 91 

 1.63 

 1. 64 



i-55 

 1.62 



i-54 



Percentage 



of free 

 creatinin. 



x 036 



.422 



■ 603 

 . 706 



.756 



. 761 

 . 670 



.742 

 .707 

 .728 



Percentage 

 of creatin 



calculated as 

 creatinin. 



694 



548 



307 

 204 



774 

 879 

 880 

 878 

 833 

 95 2 



Percentage 



of total 

 creatinin as 

 free creatinin. 



2.08 

 21. 42 



3!-57 

 36.96 

 46.38 

 46. 40 



43- 2 3 



45.80 



45- 9 1 

 43-33 



Changes in total creatinin are fairly marked. Samples incubated for 

 7, 14, and 21 days show increases in total creatinin amounting to 0.24, 

 0.18, and 0.18 per cent, respectively. Samples incubated for longer 

 periods, ranging from 28 to 100 days, show appreciable losses in total 

 creatinin varying from 0.19 to 0.05 per cent. On the whole, these data 

 show first an increase in total creatinin and later a decrease, the increases 

 being somewhat larger than the decreases. 



The changes in the free creatinin are very marked. The fresh material 

 contains 0.036 per cent of free creatinin, while the sample incubated 7 

 days contains 0.422 per cent, an actual increase of 0.386 per cent, or a 

 relative increase of ^,722 per cent. Samples incubated for 14, 21, 28, 

 and 42 days show further increases in free creatinin, but the rate of 

 increase is less rapid with each succeeding period. The maximum per- 

 centage of free creatinin, amounting to 0.761 per cent, is found in case of 

 the sample incubated 42 days. This is an actual increase of 0.725 per 



