The effect of moderate pulsed electric fields on autolysis of Saccharomyces cerevisiae and the amino acid content in autolysates

• Published in: International journal of food science & technology Vol. 56; no. 1; pp. 441 - 451
• Main Authors: Yang, Geng, Wang, Rui, Gao, Jing‐Rong, Niu, Debao, Li, Jian, Wen, Qing‐Hui, Zeng, Xin‐An
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.01.2021
• Subjects: Amino acids; Aspartic acid; Autolysis; Cell walls; Dietary supplements; Electric field strength; Electric fields; Exposure; Flavor enhancers; Flavors; Glutamic acid; Inactivation; Nutrition; pulsed electric fields; Saccharomyces cerevisiae; Umami; Yeast; Yeasts
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.14659

Summary 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. MPEF accelerates the autolysis of Saccharomyces cerevisiae and promotes the release of amino acids.