The Effect of Different Temperatures on Autolysis of Baker’s Yeast for the Production of Yeast Extract

Authors: HASAN TANGÜLER, HÜSEYİN ERTEN

Abstract: This study aimed to determine the optimum autolysis conditions for the production of yeast extract, which is used to give a meaty flavor to food products and to increase their nutritional value. Autolysis was induced by incubating baker’s yeast cell suspensions at different temperatures (45, 50, 55, and 60 °C) with a reaction time ranging from 8 to 72 h. Content and yield of total solids, \alpha-amino nitrogen (\alpha-AN), and protein were determined. Yeast extract powder was obtained by drying liquid yeast extract in a pilot scale spray drier. Sensory analysis was performed by adding the yeast extract powder at different concentrations (0.5%, 1.0%, 1.5%, and 2.0%) to vegetable soup. Optimum temperature and time for the production of yeast extract was 50 °C for 24 h, based on \alpha-AN content, which was 3.7%. Furthermore, under the same conditions, protein content was 52.5% and total solids content was 1.98%. According to sensory analysis, the sample with 0.5% yeast extract powder and the control had the highest overall acceptance. According to variance analysis, differences between total solids, \alpha-AN, and protein content determined at 4 different temperatures, and interactions between duration and temperature were statistically significant (P < 0.01).

Keywords: \alpha-amino nitrogen, Saccharomyces cerevisiae, baker's yeast, temperature, yeast extract

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