The changes in the chemical composition of yeast extracts during autolysis and their effect to the sensory quality were studied with baker´s yeast, Saccharomyces cerevisiae.
The amounts of extracted solids, proteins, amio-N. amino acids, especially glutamic acid, alanine and lysine, increased by the autolysis time up to 48 hrs.
The results of sensory evaluation made by the multiple paired comparision test and Duncan´s test indicated a significant difference is taste by the time of autolysis. In the profile test, the flavor character notes expressed by the panel were 17 different characters, 11 in aroma and 6 in taste. The character notes and the intensity of flavor changed with the time of autolysis. The sharp and beany flavor of the extracts which was autolyzed for 4 hours turned into meaty and worty flavor by 48 hours of autolysis.
A proper arrangement of the flavor characters in the quantitative descriptive chart could provide a weighted value of the flavor grade. The aroma grade index and the taste grade index correlated to the amplitudes of the profile test.
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