Screening of the key volatile organic compounds of Tuber melanosporum fermentation by aroma sensory evaluation combination with principle component analysis.

Rui-Sang Liu,Feng-Wu Bai,Hong-Mei Li,Deng-Rong Xiao,Ya-Jie Tang,Guang-Huai Jin

doi:10.1038/srep17954

Abstract

Aroma results from the interplay of volatile organic compounds (VOCs) and the attributes of microbial-producing aromas are significantly affected by fermentation conditions. Among the VOCs, only a few of them contribute to aroma. Thus, screening and identification of the key VOCs is critical for microbial-producing aroma. The traditional method is based on gas chromatography-olfactometry (GC-O), which is time-consuming and laborious. Considering the Tuber melanosporum fermentation system as an example, a new method to screen and identify the key VOCs by combining the aroma evaluation method with principle component analysis (PCA) was developed in this work. First, an aroma sensory evaluation method was developed to screen 34 potential favorite aroma samples from 504 fermentation samples. Second, PCA was employed to screen nine common key VOCs from these 34 samples. Third, seven key VOCs were identified by the traditional method. Finally, all of the seven key VOCs identified by the traditional method were also identified, along with four others, by the new strategy. These results indicate the reliability of the new method and demonstrate it to be a viable alternative to the traditional method.

Highlights

Aroma results from the interplay of volatile organic compounds (VOCs) and the attributes of microbialproducing aromas are significantly affected by fermentation conditions
Aroma results from the interplay of volatile organic compounds (VOCs), and more than 200 VOCs have been identified from natural Tuber fruiting-bodies[10,11,12,13,14]
When T. melanosporum was inoculated in a fermentation medium, an alcohol smell gradually began to appear during the fermentation process

Summary

Introduction

Aroma results from the interplay of volatile organic compounds (VOCs) and the attributes of microbialproducing aromas are significantly affected by fermentation conditions. Aroma results from the interplay of volatile organic compounds (VOCs), and more than 200 VOCs have been identified from natural Tuber fruiting-bodies[10,11,12,13,14]. The absence of a major carbon source of sucrose and the shift of culture temperature had the most significant effects on the profile of VOCs, followed by the absence of yeast extract or peptone[17] Among these VOCs reported from the Tuber fruiting-bodies, the volatile organic sulfur-containing compounds (VOSCs) www.nature.com/scientificreports/. Flowery, sweet, hay Scores such as methanethiol, dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, 3-(methylthio)-propanal, and 3-(methylthio)-1-propanol, were first detected in T. melanosporum submerged fermentation by the addition of 5 g/L L-methionine[18] These results indicated that it was possible to adjust the VOC profile by control of fermentation conditions

Methods

Results

Conclusion