The effect of moderate pulsed electric fields on autolysis of Saccharomyces cerevisiae and the amino acid content in autolysates
2021
Yang, Geng | Wang, Rui | Gao, Jing‐Rong | Niu, Debao | Li, Jian | Wen, Qing‐Hui | Zeng, Xin‐An
The effect of moderate pulsed electric fields (MPEF) strength on autolysis of Saccharomyces cerevisiae was evaluated in this study. After exposure to MPEF with intensity of 7 kV cm⁻¹ for 4 ms, the integrity of the cell wall was obviously destroyed and the inactivation of S. cerevisiae reached 99.43%. During the subsequent 42‐h autolysis process, the release of free α‐amino nitrogen of MPEF‐treated cells, as well as extracellular protease activity, was significantly (P < 0.05) higher than that of untreated cells. Moreover, exposure to 7 kV cm⁻¹ led to an increase of the total amino acid of 149.36%. In particular, the content of aspartic acid and glutamic acid which are important umami flavour precursors increased by 232.55% and 209.40%, respectively. These results indicate that MPEF will be an effective method to accelerate autolysis of S. cerevisiae for obtaining high‐quality yeast extract as flavour enhancers and nutrition supplements.
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