This was because the protein was degraded and produced free amino acids, part of which remained in the jerky to improve the flavor, and part of which was left in the fermentation medium.
Thus, the medium after fermentation had much a higher free amino acids content than before fermentation (0 mg/100 g). These free amino acids by themselves can enhance fermented meat flavor, and they can also serve as substrates for further production of flavor compounds, improving a product’s flavor and taste.
As an indispensable strain, Lactobacillus can adjust the composition of volatile and non-volatile compounds through the release and degradation of free amino acids, which further affect the flavor of fermented meat