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

Abstract 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.