Genetic Algorithm-Driven Optimization of Mixed-Strain Fermentation for Improving the Physicochemical, Antioxidant, and Sensory Properties of Wampee (Clausena lansium (Lour.) Skeels) Juice

The potential of lactic acid bacteria (LAB) to enhance fruit juice is well known; however, the optimal fermentation strategy for wampee juice (WJ), considering its physicochemical and sensory characteristics and antioxidant activity, remains to be explored. For WJ fermentation, a co-culture of three LAB strains-<i>Pediococcus pentosaceus</i> SL05, <i>Pediococcus acidilactici</i> SL08, and <i>Lactiplantibacillus plantarum</i> JYLP-002-was optimized using a combined approach of simple lattice mixture design and a genetic algorithm (GA). After 48 h of fermentation, the optimal mixed fermentation group demonstrated a comprehensive superiority over both the unfermented and single-strain fermentation groups. It exhibited significantly higher levels of viable bacterial counts, total organic acid content, total phenolic and flavonoid contents, antioxidant capacity, and an enriched profile of volatile flavor compounds. Moreover, comprehensive volatile profiling via HS-SPME-GC-MS and HS-GC-IMS identified 59 and 29 volatile components, respectively; <i>β</i>-phellandrene, <i>α</i>-terpineol, <i>α</i>-pinene, methyl acetate, (E)-3-hexen-1-ol, and 3-methyl-1-butanol, as well as butanal, (E)-3-hexenoic acid, <i>β</i>-pinene, and propyl butanoate, were considered as key aroma contributors in the fermented WJ (FWJ). This study provides a theoretical foundation and practical framework for the enhancement of WJ quality through mixed LAB fermentation.