The dynamic changes and correlations between biochemical properties, flavor and microbial community during fermentation of asparagus by-products.

Asparagus by-products are the promising resource that urgently need to be re-valorized. This study investigated the dynamic changes in physicochemical properties, organic acids, free amino acids, volatile flavor compounds, microbial succession, and their correlations during 7-day spontaneous fermentation of asparagus by-products. Dominant organic acids (lactic acid and acetic acid) and free amino acids (Ser, Glu, and Ala) increased with fermentation time, with lactic acid reaching 7.73 ± 0.05 mg/mL and Ser increasing 56-fold after 7 days. A total of 58 volatile flavor compounds were identified using headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPEM/GC–MS), with esters, alcohols and acids as the main volatile flavor compounds. Fourteen volatile flavor compounds had odor activity value >1. High-throughput sequencing showed Firmicutes and Proteobacteria as the main bacterial phyla, dominated by lactic acid bacteria (Levilactobacillus , Lactiplantibacillus , Weissella). Correlation analysis revealed that five bacterial genera (Levilactobacillus , Lactiplantibacillus , Enterobacter , Pediococcus and Acetobacter) were highly correlated with organic acids, free amino acids, and volatile flavor compounds, indicating their pivotal role in forming the characteristic flavor of fermented asparagus by-products (FAPS). This study provides new insights into the flavor and microbial profile of FAPS, offering a strategy for value-added processing and industrial production. [Display omitted] • Flavor and microbial composition were studied in fermented asparagus by-products. • Lactic acid and Ser were the main non-volatile flavor compounds. • Esters, alcohols and acids were identified as the main volatile flavor compounds. • Correlations between flavor and microbial community were revealed. • Levilactobacillus and Lactiplantibacillus were related to unique flavors. [ABSTRACT FROM AUTHOR]