Mulberry leaf tea (MT) is a popular Chinese food with nutrition and medicinal functions. Solid-state fermentation with Eurotium cristatum of MT (FMT) can improve their quality. Differences in chromaticity, taste properties, and flavor characteristics were analyzed to evaluate the improvements of the sensory quality of FMT. After fermentation, the color of the tea infusion changed. The E-tongue evaluation results showed a significant decrease in unpleasant taste properties such as sourness, bitterness, astringency, and aftertaste-bitterness, while umami and saltiness taste properties were enhanced post-fermentation. Aroma-active compounds in MT and FMT were identified and characterized. A total of 25 key aroma-active compounds were screened in MT, and 2-pentylfuran showed the highest relative odor activity value (ROAV). A total of 26 key aroma-active compounds were identified in FMT, and the newly formed compound 1-octen-3-one showed the highest ROAV, which contributed to FMT’s unique mushroom, herbal, and earthy flavor attributes. 1-octen-3-one, (E)-2-nonenal, trimethyl-pyrazine, 2-pentylfuran, and heptanal were screened as the potential markers that contributed to flavor differences between MT and FMT. E. cristatum fermentation significantly altered the sensory properties and flavor compounds of MT. This study provides valuable insights into the sensory qualities of MT and FMT, offering a theoretical basis for the development of FMT products.
The quality modification of chilled, raw conditioned mutton (RCM) after storage significantly impacts consumer preferences, making shelf-life extension and quality preservation crucial. This study evaluated the effects of sodium diacetate (SDA), sodium dehydroacetate (DHA-S), ε-polylysine hydrochloride (PLH), and nisin on RCM quality and bacterial community at concentrations of 3.0, 0.50, 0.30, and 0.50 g/kg, respectively. Major spoilage bacteria were isolated, and the inhibitory effects of these preservatives were studied, leading to the development of compound preservatives. TVC increased significantly during RCM preparation, with continuous increases in TVC and TVB-N levels throughout storage, reaching spoilage thresholds by day 5. Bacterial diversity decreased markedly, with Brochothrix and Pseudomonas dominating. SDA effectively inhibited TVC proliferation and TVB-N formation, maintaining bacterial diversity and reducing Brochothrix and Pseudomonas abundance while promoting the growth of lactic acid bacteria. Five spoilage bacteria strains were isolated, including Serratia liquefaciens B2107-1, a potent meat spoilage bacterium under refrigeration. PLH and SDA demonstrated significant inhibitory activity against this bacterium, with minimum inhibitory concentrations (MICs) of 0.175 and 0.400 mg/mL, respectively. Combining PLH and SDA at 1MIC + 3MIC exhibited a synergistic antimicrobial effect, maintaining RCM quality with reduced SDA usage. These findings demonstrate the significant potential of these preservatives in chilled, raw meat products.
Solid-state fermentation of burdock roots with Eurotium cristatum was performed to enhance their functional properties. Fermentation induced marked compositional remodeling, resulting in a 1.37-fold increase in protein content compared to unfermented controls. Antioxidant capacities were markedly enhanced. DPPH and ABTS radical-scavenging activities both exceeded 90%, and intracellular ROS levels in Caenorhabditis elegans were reduced by 62.7%. Phenolic profiling via UPLC-ESI-MS/MS identified and quantified 74 phenolic compounds across samples; notably, 10 flavonoids were exclusively detected in fermented burdock roots, indicative of microbial biotransformation. Correlation analysis integrating phenolic abundance with all three antioxidant endpoints revealed 11 compounds significantly associated with enhanced bioactivity. Among these, sinapic acid, 3-hydroxyflavone, liquiritigenin, and sakuranetin exhibited positive correlations with all three antioxidant measures. Prostaglandin G/H synthase 1 (PTGS1) and PTGS2 were identified as shared antioxidant-relevant targets, with PTGS1 highlighted due to its constitutive role in prostaglandin biosynthesis. Importantly, 3-hydroxyflavone, liquiritigenin, and sakuranetin were newly emerged following fermentation, providing direct evidence that E. cristatum mediates the synthesis or structural modification of key flavonoids, thereby augmenting the antioxidant chemical profile and functional efficacy of burdock roots.