Fate of free amino acids and nucleotides in spoiling beef.

Fresh beef allowed to undergo microbial spoilage at 7 C showed decreases in quantity and types of amino acids as well as decreases in nucleotides when the initial number of bacteria per gram was high. When the initial number of bacteria was low, decreases were either not detectable or of low orders. It seems, therefore, that low-molecular-weight compounds of the above type support the growth of beef-spoilage bacteria rather than primary beef proteins. These low-molecular-weight compounds provide the probable sources of ammonia, hydrogen sulfide, and other such compounds associated with beef allowed to spoil at low temperatures.