This research aims to investigate the effects of Staphylococcus xylosus YCC3 (Sx YCC3) and Lactobacillus plantarum MSZ2 (Lp MSZ2) on lipid hydrolysis and oxidation, the bacterial community’s composition, and the volatile flavor compounds in fermented sausage. The bacterial community was examined by plate counting and high-throughput sequencing. Differential flavor compounds in non-inoculated and inoculated sausages were identified by principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA). The results showed that the free fatty acid (FFA) content was increased after inoculating with Sx YCC3 or Lp MSZ2. The pH, peroxide value (POV), thiobarbituric acid reactive substances (TBARS) value, lipoxygenase activity, and the counts of Enterobacteriaceae were lower in the inoculated sausage than in the non-inoculated sausage. The bacterial inoculation enhanced the competitiveness of Staphylococcus and Lactobacillus and restricted the growth of unwanted bacteria. The OPLS-DA revealed that (Z)-hept-2-enal, (E)-2-octenal, 1-nonanal, octanal, and 1-octen-3-ol were common differential flavor compounds that were found in the inoculated sausages but were not found in the non-inoculated sausages. A positive correlation was observed between the differential flavor compounds and the relative abundance of Staphylococcus or Lactobacillus, or the FFA content. Our results indicated that inoculation with Sx YCC3 or Lp MSZ2 can improve fermented sausages’ flavor by enhancing their bacterial quality and increasing their FFA content.

Salted duck eggs are a popular food product, but their high salt content and uneven salt distribution can reduce acceptability. This study investigated the effects of pH-high-intensity ultrasound combined treatment on the salt-induced gelation properties of egg yolk granules. The results showed that the pH5 + 150 W treatment group exhibited the best physical and gelation properties, with the smallest particle size (1597.33 nm), optimal dispersibility (PDI 0.29), and good stability. The gelation properties of this group also demonstrated excellent springiness (0.30 mm), cohesiveness (0.56), and gumminess (0.05 N). Furthermore, the pH5 + 150 W group had the highest water holding capacity of 97.42 % and relatively high hydrophobicity (173.39 μg). Notably, it also showed high oil exudation (2.83 %) and good sandiness (62.07 %). The pH5 + 150 W led to a significant redshift of the fluorescence peak at 335 nm and an enhancement of the peak intensity at 562 nm compared to the control group. Structural characterization revealed a more ordered protein structure and a uniform gel structure with enhanced electrostatic repulsion between oil droplets. Secondary structure analysis of the proteins showed a significant reduction in α-helix and β-sheet, while β-turn and random coil increased. In summary, the pH5 + 150 W treatment displayed the best gelation properties, providing theoretical guidance for enhancing the processing performance of yolk and expanding their application in the food industry.

Eggs, as a high-nutritional food, face challenges such as limited flavor diversity and high cholesterol content in their processed products. Lactic acid bacteria (LAB) fermentation has been introduced as a method to address these issues by reducing pH, producing organic acids, and facilitating enzymatic hydrolysis, thereby enhancing the flavor and nutritional quality of egg products. This review explores the effects of lactic acid fermentation on the physicochemical, flavor, and nutritional characteristics of egg products. Research indicates that LAB can effectively improve the flavor of egg products, reduce pH, and enhance protein solubility and gel characteristics. During fermentation, LAB regulate the production of flavor compounds through enzymatic systems while promoting protein breakdown to generate bioactive peptides, which confer health benefits such as immune enhancement and lipid reduction. Furthermore, extending fermentation time significantly influences the pH and flavor compounds of egg products. This review provides a theoretical foundation for the further development of fermented egg products and is of considerable importance in meeting consumer demand for healthier foods.

Yuluxiang pear juice processing faces critical technical challenges: enzymatic browning, nutrient degradation during thermal processing, and flavor volatilization. Ultrasound (US)-assisted fermentation, an emerging non-thermal technology, enhances fruit juice quality. However, its regulatory mechanisms in fermented pear juice flavor formation remain unclear. This study investigated the effects of 0-500 W US power on Lactiplantibacillus plantarum-fermented Yuluxiang pear juice. An integrated electronic nose (E-nose), electronic tongue (E-tongue), and gas chromatography-ion mobility spectrometry (GC-IMS) system characterized physicochemical properties, antioxidant capacity, and flavor profiles. Results suggested significant power-dependent effects on fermentation quality. The 300 W treatment was associated with optimal comprehensive quality, including the lowest browning index, highest transmittance (52%), maximum polyphenol content (1.44 mg/100 mL), and greatest viable lactic acid bacteria count (1.3 × 10⁹ CFU/mL), while 400 W treatment yielded to peak ABTS radical scavenging activity (75.6%). Enzyme activity assays indicated that 300 W significantly inhibited polyphenol oxidase (70.6%) while enhancing peroxidase (112.0%) and superoxide dismutase (269.2%) compared to the untreated fermentation group (p < 0.05). E-nose revealed significantly elevated responses for W1S (esters) and W2S (alcohols/aldehydes) sensors with increasing US power. E-tongue implied that 400 W reduced bitterness/astringency and enhanced sourness. GC-IMS fingerprinting identified linalool, 2-methylbutyl acetate, and (Z)-4-heptenal as characteristic differential volatiles (VIP > 1). Correlation analysis pointed toward possible mechanistic pathways whereby acoustic cavitation modulates the physicochemical microenvironment, promoting lactic acid bacteria metabolism and polyphenol biotransformation, synergistically enhancing flavor and functional quality. This study provided theoretical insights and technical support for high-value processing of Yuluxiang pear.

Non-thermal processing technologies have emerged as promising alternatives to preserve bioactive compounds in fruit-based beverages. However, the synergistic effects of ultrasound-assisted ultra-high pressure (US-UHP) combined with lactic acid bacteria fermentation on jujube juice quality remain poorly understood. This study systematically investigated the effects of US-UHP pretreatment on physicochemical properties, bioactive compounds, volatile profiles, and sensory characteristics of fermented jujube juice (FJJ). Results demonstrated that US-UHP pretreated samples exhibited superior quality attributes. At 24'h fermentation, total phenolic content reached 2.32 mg/mL, ABTS and DPPH radical scavenging activities were 87.30% and 74.86%, respectively, and ascorbic acid content was significantly higher than other groups. After 40 h fermentation, reducing sugar consumption rate reached 54.69%. Notably, US-UHP treatment significantly improved colloidal stability, with particle size maintained at 33.41-53.21 d.nm compared to 1597.67 d.nm in untreated samples, accompanied by lower polydispersity index values. Gas Chromatography-Ion Mobility Spectrometry and Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry analyses revealed that US-UHP treatment effectively reduced undesirable flavor compounds (butyric acid, hexanal, acetaldehyde) while promoting the accumulation of floral and fruity scent-related ketones. Principal component analysis of electronic nose data confirmed distinct flavor differentiation among treatments, and sensory evaluation demonstrated that US-UHP pretreated samples achieved the highest overall acceptability scores. Correlation analysis indicated significant positive relationships between total phenolic/flavonoid contents and overall acceptance (r > 0.92). These findings demonstrate that US-UHP pretreatment synergistically enhances microbial inactivation, bioactive compound release, and metabolic efficiency, providing theoretical insights and technical guidance for high-quality FJJ development.

Conventional salted duck egg yolk (SEY) suffers from hard-core texture and undesirable flavor. This study aims to enhance SEY quality and elucidate the underlying mechanisms via high-intensity ultrasound (HIU)-assisted ethanol treatment. The results revealed that optimal 200 W treatment lowered hardness while increasing chewiness (2.22 g) and adhesiveness (0.67 g·sec), with oil exudation and sandiness rising by 59.97 % and 50.78 % respectively. These improvements correlated with elevated surface hydrophobicity (+13.15 %) and free sulfhydryl content (+65.38 %) compared to those in SEY. Structural analysis revealed HIU accelerated moisture transitions, formed microporous networks, and altered protein secondary structures with increased β-turns and decreased α-helix/random coils. Volatile profiling identified 87 compounds, where cavitation-driven lipid oxidation significantly increased key flavor enhancers: ethyl decanoate (+83.78 %) and hexyl hexanoate (+381.08 %). These synergistic modifications produced superior sensory qualities (>70 points). In conclusion, this study provides an efficient and practical solution to the textural and flavor challenges in conventional SEY production.