Stage-dependent microbial succession and metabolite profiles of Phyllanthus emblica L. fruit wines produced under different temperature and pomace treatments

Abstract

Juice wine fermented at 20 °C (FW) and pomace-containing juice wine fermented at 20 °C (PW) were investigated, with juice wine fermented at 26 °C (CK) included as a conventional-temperature reference. Microbial communities and volatile profiles were characterised in all treatments using 16S rRNA gene and ITS amplicon sequencing and HS-SPME–GC–MS, whereas untargeted LC–MS metabolomics compared FW and PW. The treatments exhibited distinct stage-dependent microbial succession and chemical profiles. Saccharomyces-assigned sequences dominated the fungal communities, whereas bacterial composition varied among stages and treatments, with a transient increase in Gluconobacter-assigned sequences in PW. Overall, 2936 non-volatile features were tentatively annotated, and differential features were mainly associated with organic acids and carbohydrates. Volatile profiles differed in the relative proportions of alcohol-, ester-, acid-, and terpenoid-related features. Microbe–metabolite correlations were stage dependent but did not establish causality. These findings provide a compositional reference for P. emblica wine fermentation.