Whole egg is a nutrient-dense matrix, yet its application in beverages is often constrained by poor colloidal stability and “eggy” off-flavor. This study elucidated dose-dependent effects of mixed lactic acid bacteria inoculation on the physicochemical properties, protein structural evolution, and flavor quality of a fermented whole-egg beverage (WEB). A 1:1 (V/V) mixture of L. delbrueckii subsp. bulgaricus and Streptococcus thermophilus (total viable count: (1.1 ± 0.1) × 10⁹ CFU/mL) was inoculated into pasteurized whole egg beverage matrix at 0%, 1%, 3%, 5% and 7% (V/V), corresponding to groups WE, FWE-1%, FWE-3%, FWE-5% and FWE-7%. Fermentation proceeded at 42 °C for 4 h, followed by 36 h ripening at 4 °C. All samples were characterized using dispersion metrics, spectroscopy, electrophoresis, in vitro digestion, gas chromatography-ion mobility spectrometry, electronic nose, electronic tongue, and sensory evaluation. Fermentation acidified WEB, to pH 4.15–4.36, decreased relative turbidity (normalized to the control), and improved dispersion uniformity (minimum polydispersity index was 0.305 at 7%). Soluble protein content increased to 10.24–12.27 mg/g (vs. 2.53 mg/g in the control), and antioxidant capacity was enhanced, with 1,1-diphenyl-2-picrylhydrazyl radical and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical scavenging rates reaching 95.84% (FWE-5% group) and 82.14% (FWE-7% group), respectively. Second-derivative ultraviolet, intrinsic fluorescence, and Fourier transform infrared spectroscopy amide I redshift indicated protein conformational remodeling, supported by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showing progressive degradation of high-molecular-weight subunits. These changes improved nutritional functionality, with in vitro protein digestibility maximized at 3% inoculation. Flavor analyses revealed fermentation-driven reconfiguration of volatile and taste profiles, including aroma enrichment and reduced bitterness. Sensory results identified 3% inoculation as optimal, delivering the highest overall acceptability with balanced sourness and diminished eggy odor. This research provides a scientific basis for optimizing inoculation levels in fermented WEB and offers new perspectives for the development of functional egg-based fermented products.

This study investigated the effects of ultrasound-treated raw milk on the quality of Cheddar cheese by applying ultrasound treatment at six different combinations of temperature (40, 50 and 60 ℃) and duration (15 and 30 min). Cheese made from pasteurized (63 ℃, 30 min) milk served as a control. The physicochemical properties, texture characteristics, rheological properties, yield, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns, and protein contents of cheese samples were measured. The results demonstrated that compared with the control group, ultrasonic treatment increased the water activity, elevated the pH value, and enhanced the thermal stability and texture properties. Ultrasonic treatment at 50 ℃ for 30 min resulted in the best texture, sensory and rheological properties of Cheddar cheese, while ultrasonic treatment at 40 ℃ for 30 min resulted in the highest cheese yield (12.34%). Cheese yield was not significantly affected by either ultrasonic temperature or time (P > 0.05). Moreover, ultrasonic treatment significantly increased the pH 4.6-soluble nitrogen content (P < 0.05), with the highest value of 1.54% being observed using ultrasonic treatment at 40 ℃ for 30 min. In summary, ultrasonic treatment at 50 ℃ promoted protein crosslinking and homogenization of fat globules to form compact networks, thereby improving cheese quality; however, ultrasonic treatment at 60 ℃ aggravated protein denaturation and consequently resulted in deterioration of cheese texture.

Hot brine stretching of Mozzarella cheese can lead to the loss of protein and other components, while whey, which is rich in nutrients such as whey protein, has an important influence on the protein structure and functional characteristics of cheese. In this study, the effects of different stretching temperatures (65, 75, 85, and 95 ℃) in whey on the physiochemical and textural characteristics of Mozzarella cheese were investigated by using brine at 95 ℃ as a control. The results showed that the yield of stretched cheese in whey at 75 ℃ was as high as 7.38%, which was significantly higher than that of the other treatments (P < 0.05), and the cheese had good texture characteristics. In contrast, the stretched cheese in whey at 85 ℃ had the best sensory quality. Scanning electron microscopy analysis showed that at 75 ℃, the protein cross-linking was moderate and the cheese had an ideal balance of elasticity and hardness. Through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, it was found that stretching in whey at 75 ℃ more effectively retained the protein components in cheese. Additionally, rheological analysis indicated that the cheese subjected to hot stretching in whey exhibited better elastic properties.

In order to study the effect of co-fermentation of dough by Pediococcus acidilactici and Saccharomyces cerevisiae on the structural and physicochemical properties of wheat starch, starch was extracted from sourdough co-fermented with the two strains for 0, 6, 24 and 42 h and evaluated for physicochemical and structural properties such as solubility, swelling potential, and pasting characteristics. The results showed that the co-fermentation increased the starch content, solubility, swelling potential, and transparency. Scanning electron microscopy (SEM) and particle size analysis showed that the co-fermentation resulted in more serious surface erosion of starch than did pure culture fermentation by S. cerevisiae, and decreased the particle size by 1.19 μm. Infrared spectroscopy and crystal structure analysis showed that fermentation neither resulted in the production of new functional groups nor changed the crystal structure of wheat starch; however, the co-fermentation increased the crystallinity of starch by 2.15% and the thermal stability by 3.70 J/g compared with pure S. cerevisiae fermentation. The pasting characteristics indicated that the co-fermentation hindered the short-term aging of starch and promote the development of the gel network structure of starch granules. In summary, the co-fermentation was more likely to change the structure and physicochemical properties of starch than S. cerevisiae fermentation of. Therefore, the co-fermentation could effectively improve the properties of wheat starch, thus improving the food quality.

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.