Traditional fermented sausage ‘Nem chua’ as a source of yeast biocatalysts efficient for the production of the aroma compound γ‐decalactone

Abstract

The yeast ecosystem of Nem chua, a Vietnamese traditional fermented sausage naturally rich in mediumchain-length lipid-derived flavouring compounds, was investigated to select biocatalysts able to produce the C10-fatty acid-derived aroma compound c-decalactone. The total number of yeast was about 5 9 10 4 to 4 9 10 5 CFU g À1 , and eighty four different species were identified from morphological, physiological and 26S rDNA characteristics, with Candida sake and Candida haemulonii being found in all samples. Six strains able to produce c-decalactone from castor oil were selected, of which three Yarrowia lipolytica strains were able to produce between 1 and 2 g L À1 in our study. The strains produced the same amount from the acyl substrate under the form of ester or free fatty acid. Every strain degraded the product at the end of the culture. These high productions make them good candidates for industrial processes and confirm that traditional fermented foods are interesting bioresources for biocatalysts.

Prospects for Food Fermentation in South-East Asia, Topics From the Tropical Fermentation and Biotechnology Network at the End of the AsiFood Erasmus+Project

“…Five strains of Yarrowia , Moniliella , and Candida sp. were selected for their ability to produce the volatile compound among which, three strains were able to produce more than one g/L in pilote scale conditions ( Do et al, 2014 ). However, to keep the typicity of the product, each function performed by fermentation has to be fulfilled by the starter.…”