발효숙성 기간과 온도에 따른 유산균 접종 된장의 이화학적 및 기능적 품질특성

초록

Purpose: This study investigated the physicochemical and quality changes in soybean paste inoculated with Lactobacillus plantarum during fermentation at different temperatures, aiming to provide scientific evidence for the development of lactic acid bacteria-fortified soybean paste products. Methods: Soybean paste inoculated with L. plantarum was fermented at 25°C and 4°C for six months. The physicochemical properties, including the proximate composition and total reducing capacity, were analyzed. The free amino acid profiles were evaluated with emphasis on proteolysis-related amino acids, γ-aminobutyric acid (GABA) metabolism, and nitrogenous compounds associated with ethyl carbamate (EC) precursors. The color parameters, texture profile analysis, particle size distribution, and oxidative stability under an iron-ascorbate-induced oxidation system were also assessed. Results: The moisture content increased with fermentation, while the crude protein, crude fat, and dietary fiber decreased, reflecting combined effects of moisture dilution and microbial degradation, with fermentation duration exerting a stronger influence than temperature. The titratable acidity increased during early fermentation and decreased during late aging, whereas the pH remained relatively stable, indicating enhanced buffering capacity within the soybean paste matrix. The total free amino acid concentrations approximately doubled after six months, with concomitant increases in leucine, phenylalanine, glutamic acid, and GABA. Nitrogenous compounds related to EC precursors accumulated as the fermentation time increased, showing preferential citrulline accumulation during the later stages. Texture analysis indicated progressive softening. Particle size changes were observed mainly in the fine fraction, and the oxidative stability improved with prolonged fermentation, particularly at 25°C. Conclusion: The fermentation duration predominates over temperature in shaping the compositional, structural, and functional properties of L. plantarum–inoculated soybean paste.

키워드