Abstract:

The starter culture used for producing cheese in this study was modified by sequential treatment with lysozyme
and then ultrasonic irradiation after culture in the presence of skim milk, and the modified product was added at different
levels to the cheese to accelerate the ripening process. By doing so, this study aimed to examine the effect of the modified
starter on the formation of free amino acids and biogenic amines including histamine, tyramine, phenylethylamine,
tryptamine and cadaverine during the accelerated ripening of cheese. The contents of these compounds after 0, 30, 60 and
90 days of ripening were determined. Results showed that the contents of biogenic amine and free amino acids were higher
in cheese ripened with the modified starter than in the control group during cheese ageing, indicating that the addition of the
modified starter can result in higher contents of biogenic amines and free amino acids in a concentration-dependent manner.

Key words: cheese, biogenic amines, free amino acids