Modulation of Acidic and Sweet Taste in Reconstituted Tobacco Sheets through Microbial Co-Cultivation and Enzymatic Hydrolysis

Traditional reconstituted tobacco production is often limited by a monotonous flavor profile and insufficient utilization of natural components. Biotechnology, known for its green, efficient processes and capability for targeted metabolic regulation, has emerged as a promising strategy to improve product quality. In this study, a synergistic system combining microbial co-fermentation and enzymatic hydrolysis was developed to modulate the acidic and sweet taste attributes of reconstituted tobacco sheets. A co-culture of Lactiplantibacillus plantarum and Saccharomyces cerevisiae was applied alongside compound enzymatic treatment using cellulase and pectinase to process various tobacco sheets. In single-strain fermentations, L. plantarum significantly enhanced acidity (acid value (a measure of free fatty acid content indicating the level of acidity) increased from −25.56 to −21.36), while S. cerevisiae improved sweetness and aroma. However, neither strain alone achieved a well-balanced acid-sweet profile. Enzymatic hydrolysis using a cellulase to pectinase ratio of 2:1 effectively disrupted cell wall structure, promoting the release of soluble sugars and intensifying both acidic and sweet sensory perceptions. The combined application of microbial co-cultivation and enzymatic hydrolysis yielded the most desirable results, driven by mechanisms such as sequential carbon source utilization (S. cerevisiae consuming monosaccharides to produce ethanol, while L. plantarum metabolized polysaccharides to generate organic acids), enzyme-microbe interactions (system pH aligned with enzyme activity optima), and the co-production of flavor compounds. This approach lowered the acid value to approximately −21.05, increased the sweetness index to 0.19, and enhanced acid-sweet balance, aroma richness, and overall sensory acceptability by 10 - 15 units compared to the untreated controls. The method demonstrated broad applicability across diverse tobacco sheets. These findings highlight the metabolic interplay within microbial consortia and the catalytic role of enzymatic hydrolysis in converting flavor precursors, providing a theoretical foundation for the precise integration of biotechnology into tobacco processing. For industrial implementation, strategies such as sequential dual-strain inoculation, gradient enzymatic hydrolysis, online metabolic monitoring, and immobilized microbial agents are recommended to achieve standardized flavor regulation in reconstituted tobacco products.