Effects of kombucha-derived microbial fermentation on the flavor profile of grape fruit pulp based on electronic nose analysis, HPLC, GC-MS and GC-IMS.

BACKGROUND

The present study aimed to develop an alcohol-free fermented beverage by fermenting Cabernet Sauvignon grape puree using a defined microbial consortium isolated from kombucha, comprising Hannaella zeae, Lactiplantibacillus plantarum, Lentilactobacillus pentosus, Acetobacter pasteurianus and Komagataeibacter intermedius.

RESULTS

Significant physicochemical changes were observed post-fermentation: the sugar-acid ratio decreased markedly from 34.18 to 10.8. The contents of total esters and total phenolics increased by 31.3% (reaching 147.26 mg L-1) and 16.8% (reaching 4.51 mg GAE g-1), respectively. Analysis via gas chromatography-ion mobility spectrometry and gas chromatography-mass spectrometry identified 11 newly formed volatile compounds, including isopentyl isovalerate (imparting banana aroma, 2035.36-2198.9 μg L-1) and hexanoic acid (imparting goaty notes). Key aroma-active compounds with odor activity values (OAV) >1 were isoamyl acetate (OAV = 68.6-73.3) and β-damascenone (OAV = 98.6-281.1). Sensory evaluation revealed a significantly improved balance between fruit aroma and acidity (P < 0.05) and the overall sensory score increased by 23.5% compared to the unfermented control.

CONCLUSION

The defined kombucha-derived microbial consortium effectively enhanced the flavor complexity and sensory quality of the beverage, providing a scientific basis for the industrial production of novel alcohol-free fermented grape beverages. © 2025 Society of Chemical Industry.