ZHANG Shiyi, LYU Jiayao, WU Shan, WANG Peng, LI Ting, ZHOU Lanqi, ZHANG Youyou, DUAN Xinting, SHI Xingren, SHI Mingying, TIAN Honglei, WANG Zesheng, LIN Yuquan, SHI Lin
Using strawberry juice as the raw material, the mixed fermentation conditions of Lactiplantibacillus plantarum 85 (LP85) and Streptococcus salivarius subsp.thermophilus 81 (ST81) were optimized.Compared to fresh fruit juice, a comprehensive analysis was conducted on the sensory scores, physicochemical indicators, and volatile compound composition of the pasteurized strawberry fermented juice.Cell experiments were employed to reveal its nutritional benefits.Results from the orthogonal experiment revealed that optimal fermentation conditions were a 3∶1 ratio of LP85 to ST81 at a concentration of 107 CFU/mL, with 100 g/L sugar addition, an initial pH of 4.0, fermentation at 37 ℃ for 14 hours, followed by pasteurization for 30 minutes (T14-5).Fermentation improved sensory scores, reduced browning, and enriched the contents of phenolic compounds and antioxidant properties.Headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis identified 47 volatile flavor compounds, predominantly esters, in the fresh juice and T14-5, with significant increases in n-octanal and ketones in T14-5 compared to the fresh juice.T14-5 significantly increased the cell viability of lipopolysaccharide-induced inflammatory RAW264.7 cells in a dose-dependent manner, reduced levels of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), monocyte chemoattractant protein-1 (MCP-1), nitric oxide (NO), prostaglandin e2 (PGE2), and interleukin-6 (IL-6).In addition, T14-5 alleviated insulin resistance and apoptosis in high-glucose-induced HepG2 cells, while enhancing glucose consumption, alongside with the downregulation of glucose-6-phosphatase (G6pase), glycogen synthase kinase-3β (GSK3β), and toll-like receptor 4 (TLR4), and the upregulation of glucose transporter 4 (GLUT4), insulin receptor (INSR), and protein kinase B (AKT).Results provide a theoretical basis for the product development of pasteurized probiotic fermented strawberry juice, indicating its potential to become a healthy drink with commercial value.