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Understanding mechanisms of myofibrillar protein gelation is important for development of gel-type muscle foods. The protein-protein interactions are largely responsible for the heat-induced gelation. Exogenous additives have been extensively applied to improve gelling properties of myofibrillar proteins. Research has been carried out to investigate effects of different additives on protein gelation, among which low molecular substances as one of the most abundant additives have been recently implicated in the modifications of intermolecular interactions. In this review, the processes of myosin dissociation under salt and the subsequent interaction via intermolecular forces are elaborated. The underlying mechanisms focusing on the role of low molecular additives in myofibrillar protein interactions during gelation particularly in relation to modifications of the intermolecular forces are comprehensively discussed, and six different additives i.e. metal ions, phosphates, amino acids, hydrolysates, phenols and edible oils are involved. The promoting effect of low molecular additives on protein interactions is highly attributed to the strengthened hydrophobic interactions providing explanations for improved gelation. Other intermolecular forces i.e. covalent bonds, ionic and hydrogen bonds could also be influenced depending on varieties of additives. This review can hopefully be used as a reference for the development of gel-type muscle foods in the future. [ABSTRACT FROM AUTHOR]

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Background: Lipid droplets (LDs) are important multifunctional organelles responsible for lipid metabolism of postmortem muscle. However, the dynamics in their building blocks (cores and layers) and phosphorylation of lipid droplet‐related proteins (LDRPs) regulating meat lipolysis remain unknown at salt‐stimulated conditions. Results: LDRPs extracted from cured porcine biceps femoris (1% and 3% salt) were subjected to label‐free quantitative phosphoproteomic analysis and LDs morphological validation. Results indicated that 3% salt curing significantly decreased triglyceride (TG) content with increase in glycerol and decrease in LDs fluorescence compared to 1% salt curing. Comparative phosphoproteomics showed that there were significant changes in phosphorylation at 386 sites on 174 LDRPs between assayed groups (P < 0.05). These differential proteins were mainly involved in lipid and carbohydrate metabolism. Curing of 3% salt induced more site‐specific phosphorylation of perilipin 1 (PLIN1, at Ser81) and adipose triglyceride lipase (ATGL, at Ser399) than 1%, whereas the phosphorylation (at Ser600) of hormone‐sensitive lipase (HSL) was up‐regulated. Ultrastructure imaging showed that LDs were mostly associated with mitochondria, and the average diameter of LDs decreased from 2.34 μm (1% salt) to 1.73 μm (3% salt). Conclusion: Phosphoproteomics unraveled salt‐stimulated LDRPs phosphorylation of cured porcine meat provoked intensified lipolysis. Curing of 3% salt allowed an enhanced lipolysis than 1% by up‐regulating the phosphorylation sites of LDRPs and recruited lipases. The visible splitting of LDs, together with sarcoplasmic disorganization, supported the lipolysis robustness following 3% salt curing. The finding provides optimization ideas for high‐quality production of cured meat products. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Graphene in photocatalyst composite plays a critical role in carriers transfer and separation, and the design of photocatalysts with graphene is considered as an effective method to improve the photocatalytic performance. In this work, a series of visible light-driven Cu2O/TiO2/rGA photocatalysts were fabricated by hydrothermal and reflux reductive method to degrade the UDMH (unsymmetrical dimethylhydrazine) gas. The maximum conversion could achieve 62.6% when the reduction reflux time was 120 min, which is ascribed to the superior synergy of absorption and photocatalysis. The absorption was mainly from the high specific surface area of Cu2O/TiO2/rGA (reduced graphene oxide aerogels) and affinity of copper for UDMH, while the semiconductor and graphene contribute to the photocatalysis. The Z-scheme heterojunction mechanism was proposed to explain the enhancement of UDMH degradation based on the detected O2•− and •OH reactive species and bandgap structure. In addition, the Cu2O/TiO2/rGA photocatalyst showed stable performance in the degradation of UDMH gas through experimental results and characterization. [ABSTRACT FROM AUTHOR]