Roles of Proteins/Enzymes from Animal Sources in Food Quality and Function

Improving gel properties of silver carp (Hypophthalmichthys molitrix) myosin with flavonols: Unveiling the advantages of isorhamnetin

This study explores the impact of flavonols (kaempferol, quercetin, kaempferitrin, and isorhamnetin) on the gel properties of myosin derived from silver carp (Hypophthalmichthys molitrix). Before employing a two-stage heating process, myosin samples are pretreated with flavonols, which enhance the structural stability of myosin and aid in the dispersion of myosin molecules. These pretreatments prepare the samples for subsequent thermal processing, where flavonols facilitate myosin unfolding and enhance intermolecular aggregation, thereby improving gel strength. This process also transforms free water within the gel to bound water, significantly increasing the water-holding capacity. Both macroscopic and microscopic rheological analyses suggest that flavonols, particularly isorhamnetin, notably enhance the elasticity and viscosity of myosin during the gelation process. Further, microstructural examinations employing techniques such as small-angle X-ray scattering and micro-computed tomography demonstrate that samples treated with flavonols develop denser and more uniform gel networks. Analytical studies reveal that flavonols, especially methylated derivatives like isorhamnetin, effectively promote gelation through strengthening hydrophobic interactions, disulfide bonds, and ionic interactions among myosin molecules. This research underscores the potential of flavonols as natural additives to enhance the quality and functional properties of surimi products, thereby elevating the processing standards of aquatic products.

The Changes Occurring in Proteins during Processing and Storage of Fermented Meat Products and Their Regulation by Lactic Acid Bacteria

Protein, which is the main component of meat, is degraded and oxidized during meat fermentation. During fermentation, macromolecular proteins are degraded into small peptides and free amino acids, and oxidation leads to amino acid side chain modification, molecular crosslinking polymerization, and peptide chain cleavage. At different metabolic levels, these reactions may affect the protein structure and the color, tenderness, flavor, and edible value of fermented meat products. Lactic acid bacteria are currently a research hotspot for application in the fermented meat industry. Its growth metabolism and derivative metabolites formed during the fermentation of meat products regulate protein degradation and oxidation to a certain extent and improve product quality. Therefore, this paper mainly reviews the changes occurring in proteins in fermented meat products and their effects on the quality of the products. Referring to studies on the effects of lactic acid bacteria on protein degradation and oxidation from all over the world, this review aims to provide a relevant reference for improving the quality of fermented meat products.