Yunqi Wen

Antarctic krill oil (AKO) contains a complex lipid matrix characterized by abundant phospholipids and long-chain n-3 polyunsaturated fatty acids, which limits the usefulness of any single index for quality assessment. Here, 19 commercial AKO capsule samples were evaluated across multiple physicochemical and sensory dimensions, including primary and secondary oxidation, color, sensory properties, fatty acid and phospholipid composition, tocopherol, etc. Additionality, relationships among these attributes were explored. Marked differences among samples were evident in oxidative, compositional, colorimetric, and sensory characteristics. POV and AnV were not significantly associated, suggesting that primary and secondary oxidation varied independently across the sample set. Increasing POV coincided with greater lightness and lower redness and yellowness, whereas AnV was unrelated to color but increased with rancid odor intensity. EPA and DHA exhibited strong co-variation, and AV was closely associated with lysophosphatidylcholine. Elemental concentrations showed little correspondence with POV or AnV. PC1 and PC2 accounted for 27.1% and 16.9% of the dataset variability, respectively, showing that sample differentiation involved several compositional, oxidative, colorimetric, and sensory dimensions. These findings indicate that multidimensional profiling provides a more informative representation of commercial AKO quality than assessment based on a single conventional parameter.

Spent brewer's yeast (SBY), a protein-rich byproduct of beer production, has limited value-added utilization because intracellular components are inefficiently released. This study investigated NaCl pretreatment coupled with stepwise enzymatic hydrolysis to enhance umami-related compound release from SBY. The optimized G6 process used 60 g/L NaCl for 6 h, followed by cell-wall lytic enzymes (5 g/kg) for 3 h and Flavorzyme (5 g/kg) for 3 h. G6 achieved the highest amino acid nitrogen content (0.51 g/dL) and umami value, 3.02-fold that of NaCl treatment alone, while GMP reached 33.4 mg/L. Transcriptomics identified 2,288 differentially expressed genes, including downregulation of several cell-wall-related genes, while scanning electron microscopy revealed increased surface irregularity and deformation after NaCl treatment. These changes suggest that NaCl pretreatment altered yeast cell-wall characteristics, potentially facilitating subsequent enzymatic hydrolysis. The process offers a feasible approach for SBY valorization as an umami-rich food ingredient.

Spent brewer's yeast (SBY), a major byproduct of the beer industry, contains abundant proteins (40-65%), β-glucans and bioactive compounds, traditional utilization methods of which suffers from high energy consumption and low efficiency. This study explored the utilization of SBY as raw material in the fermentation of umami condiment, coupled with salt stress treatment and stepwise enzymatic hydrolysis to improve the brewing efficiency. Among all treatment groups, the strategy combining NaCl pretreatment with stepwise enzymatic treatment (5 g/kg cell wall lytic enzymes for 3 h followed by 5 g/kg the application of Flavorzyme for 3 h) achieved the best performance, resulting in amino acid nitrogen content of 0.51 g/dL in fermented product, 302% increase in umami value compared to the group treated only with salt, and GMP concentration increasing from 0 to 33.4 mg/L. Transcriptomic analysis revealed potential influence mechanisms of NaCl pretreatment: salt stress downregulated key genes including MNN2, MNN5, and GAS1, inhibiting yeast cell wall synthesis and remodeling cell structure, thereby increasing cell wall permeability and enzyme accessibility. This study proposed an efficient SBY utilization strategy to prepare umami condiments, providing insights for sustainable food ingredient development within a circular economy framework.

Plant growth regulators (PGRs) are extensively applied in cherry cultivation to enhance fruit quality. While sodium 4-chlorophenoxyacetate (4-CPANa) is a registered plant growth regulator for cherries, its specific effects on fruit quality and flavor are poorly understood. Herein, the effect of 4-CPANa on the flavor quality of 'Meizao' cherry and the mechanism underlying these effects was investigate combined with metabolomics and transcriptomics. The results indicated that while 4-CPANa improved the taste quality of cherry fruit by increasing the sugar-to-acid ratio and promoting key amino acid accumulation, it concurrently enhanced grassy volatile compounds likely via regulating key genes in the jasmonic acid, ethylene, and α-linolenic acid metabolic pathways, thereby affecting the overall flavor profile. This research provides valuable insights for regulating cherry flavor and promoting the high-quality, sustainable development of the cherry industry.

Spent brewer's yeast (SBY), a major byproduct of the beer industry, contains abundant proteins (40-65%), β-glucans and bioactive compounds, traditional utilization methods of which suffers from high energy consumption and low efficiency. This study explored the utilization of SBY as raw material in the fermentation of umami condiment, coupled with salt stress treatment and stepwise enzymatic hydrolysis to improve the brewing efficiency. Among all treatment groups, the strategy combining 6% NaCl pretreatment with stepwise enzymatic treatment (0.5% w/w cell wall lytic enzymes for 3 h followed by 0.5% w/w flavor enzyme for 3 h) achieved the best performance, resulting in amino nitrogen content of 0.51 g/100mL in fermented product, 302% increase in umami value compared to the group treated only with salt, and GMP concentration increasing from 0 to 33.4 mg/L. Transcriptomic analysis revealed potential influence mechanisms of NaCl pretreatment: salt stress downregulated key genes including MNN2, MNN5, and GAS1, inhibiting yeast cell wall synthesis and remodeling cell structure, thereby increasing cell wall permeability and enzyme accessibility. This study proposed an efficient SBY utilization strategy to prepare umami condiments, providing insights for sustainable food ingredient development within a circular economy framework.