Effect of Dendrobium nobile Lindl. on volatile flavor substances and nonvolatile metabolites of rice wine fermented by Saccharomyces cerevisiae and Wickerhamomyces anomalus monocultures

Abstract

In order to investigate the effect of Dendrobium nobile Lindl. (DNL) on the quality of rice wine fermented by Saccharomyces cerevisiae (DnSC) and Wickerhamomyces anomalus (DnWA), respectively, the physicochemical indexes, active ingredients, free amino acids, volatile flavor substances and nonvolatile metabolites of rice wine based on chemical methods, GC-MS and nontargeted metabolomics were studied. Results showed that the addition of DNL had a significant effect on the contents of physicochemical indicators. Compared with the fermented rice wine without the addition of DNL, the contents of active ingredients, free amino acids and volatile flavor components in DnSC and DnWA were all significantly increased. Among them, compared with SC, the contents of polysaccharides, flavonoids, total phenols and free amino acids in DnSC rose by 46.67 %, 27.07 %, 20.45 % and 50.14 % respectively. And compared with WA, these active ingredients in DnWA rose by 25.45 %, 20.13 %, 10.77 % and 46.01 % respectively. Notably, after adding DNL, the content of dendrobine in rice wine increased from 0 to 14.53 PPM (DnSC) and 11.41 PPM (DnWA) respectively. The volatile flavor compounds in DnWA rice wine were the most abundant (45 kinds), among which 14 kinds of alcohols were detected. The content of volatile flavor compounds in DnSC rice wine was the highest (45.45 mg/mL), among which 18 kinds of esters were detected. There were significant differences in flavor compounds between different rice wines, which give different aromatic styles and characteristics. Metabolomics analysis showed that the overall expression of metabolic pathways in rice wine was almost up-regulated by the addition of DNL, which resulted more metabolites in rice wine. The metabolic pathways that caused significant differences in Sc-fermented rice wine were the metabolism of nicotinate and nicotinamide and the metabolism of glyoxylate and dicarboxylate, while in Wa-fermented rice wine, they were the metabolism of phenylalanine and the metabolism of galactose. These results provide a theoretical basis for the development of DNL and its application in fermented rice wine.