Effect of temperature, NaCl and ferulic acid concentration on bioconversion of ferulic acid to 4-vinylguaiacol and 4-ethylguaiacol by halotolerant yeasts Candida versatilis

Abstract

Decarboxylation of ferulic acid (FA) to 4-vinylguaiacol (4-VG) followed metabolized to 4-ethyl guaiacol (4-EG) via yeast metabolism are inherent to soy sauce fermentation process. 4-EG (Smoky-like and sauce flavour) is a representative flavour component in soy sauce. In this work, 4-EG generated from ferulic acid (FA) by Candida versatilis after different NaCl and temperature treatments were investigated. The results showed as following: (1) the yield of 4-ethylguaiacol and 4-vinylguaiacol on ferulic acid was 20% (w/w); (2) the production of 4-VG and 4-EG may be improved by adding salt; (3) the production of 4-VG and 4-EG can be enhanced by cultivating under suitable growth temperature.