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In order to study the effects of different functional strains on alleviating protein oxidation and enhancing flavor in fermented sausage, Lactiplantibacillus plantarum NJAU-01 (LpN), with excellent antioxidant activity, L. plantarum CGMCC 18217 (Lp10), with the ability to improve the flavor of fermented sausage, and Staphylococcus saprophytic CGMCC 3475 (Ss), with high protease activity, were selected for use in a multi-strain starter culture for fermented sausage. The degree of protein degradation and oxidation in fermented sausage during fermentation and the final flavor of the product were evaluated. The results showed that the Lp10 + LpN + Ss starter culture could reduce the degree of protein oxidation in fermented sausage and increase the types and contents of volatile flavor substances, while endowing fermented sausage with better color and improving its texture characteristics, and the fermented product had high sensory scores. This study showed that the combination of Lp10, LpN and Ss could improve the quality and flavor of fermented sausage while delaying the oxidation of protein.

The effects of adding different amounts (0.1%–0.5%) of arabic gum (AG) or guar gum (GG), natural polysaccharides with similar molecular mass but different viscosity, on the emulsifying properties of myofibrillar protein (MP) were investigated. The results showed that both AG and GG could significantly improve the emulsifying properties of MP, and AG was more effective in improving the emulsifying activity, while GG was more conducive to the emulsion stability. Both emulsifying activity index (EAI) and emulsion stability index (ESI) initially increased and then decreased with increasing the amount of added polysaccharides, reaching maximum values when 0.3% AG or 0.2% GG was added. Both polysaccharides, especially GG, resulted in a marked reduction of the interfacial protein content. The droplet size of emulsions gradually decreased with increasing the amount of added polysaccharides, and the droplet size distribution became more uniform. When more than 0.3% GG was added, slight flocculation occurred in the emulsions. At the same concentration, GG reduced the droplet size of the emulsions compared to AG. Rheological analysis confirmed that all emulsions were pseudoplastic fluids, exhibiting weak gel properties. AG at low levels (≤ 0.3%) caused a decrease in the viscosity of the emulsions while remarkably increasing the storage modulus. In contrast, the addition of GG significantly increased the apparent viscosity and storage modulus of the emulsions. Compared with AG, the emulsion prepared with GG, with higher viscosity, exhibited greater apparent viscosity and storage modulus, which was more favorable to the emulsion stability.

Protein fibrils formed through self-assembly are expected to be used as a novel functional ingredient in food industry, on account of their abundant amino acids, straight morphology, and multi-level and multi-scale structures. The development and utilization of protein fibrils have become a research hotspot in the food field in recent years, notably the research on plant-derived protein self-assembled fibrils that are more in line with the needs of green and sustainable development has attracted considerable attention. In this paper, the formation mechanism and influencing factors of plant-derived protein fibrillization are introduced. Especially, the impact of fibrous self-assembly on the protein structure and techno -functional properties, as well as the application status and development prospects of protein fibrils in the food field are highlighted, with a view to provide a theoretical basis for the development and utilization of plant protein fibrils in the field of functional food. [ABSTRACT FROM AUTHOR]

BACKGROUND Heat‐induced composite gels were prepared with 20 g kg−1 myofibrillar protein (MP) sol, 20 g kg−1 modified starch and 100 g kg−1 lipid pre‐emulsified by MP in 0.6 mol L−1 NaCl, at pH 6.2. The effects of esterified potato starch (EPS) and emulsified lipid (lard or peanut oil) on the rheology, texture properties and nuclear magnetic resonance characterization of MP gel were evaluated. RESULTS: The addition of starch and lipid significantly improved the gel strength and water holding capacity (WHC) of the MP gel. Analysis of the relaxation time compared with the WHC tests showed that the variation range of the transverse T22 relaxation time of a gel was positively proportional to changes in WHC of the composite gel, and the lower the T22 relaxation time, the better the WHC of composite gel. Moreover, MP gel with starch and emulsified lard added at the same time has the lowest T2 relaxation time, and also the best WHC of the gel. Environmental scanning electron microscopy showed that emulsified oil droplets embedded the gaps in the protein network, and the gelatinized starch contributed to restrict the oil droplet size, resulting in thicker MP gel. CONCLUSION: Emulsified lipid and modified starch have an important influence on the rheology and microstructure of MP gels, indicating the subtle interaction between starch, lipid and protein. The results suggest the potential feasibility of modified starch and vegetable oil to improve the textural properties in comminuted meat products. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]