Suisui Jiang

Pectin polysaccharides from cascara are rich in rhamnogalacturonan I, which has good potential for regulating lipid metabolism. Improvement of lipid metabolism disorders is crucial for the treatment of metabolic dysfunction-associated fatty liver disease (MAFLD). This study revealed the physicochemical properties of cascara pectin polysaccharides (CPP), further evaluated their effects on MAFLD, and explored the underlying mechanisms. In this study, CPP significantly alleviated liver damage induced by a high-fat diet. Mechanistically, CPP increased the level of fumarate through decreasing the levels of fumarate hydrase and proteobacteria. Molecular docking analysis revealed that there was a direct interaction between fumarate and AMP-activated protein kinase α. Moreover, CPP promoted cholesterol clearance through the AMPK-FOXO3a-PCSK9-LDLR signaling pathway. Collectively, CPP may mitigate HFD-induced hepatic steatosis through the gut microbiota-metabolite-lipid pathway. As a sustainable prebiotic agent, CPP may provide a scientific foundation for dietary interventions in MAFLD management.

High hydrostatic pressure (HHP) treatment is a non-thermal processing technology, which is widely used in the food processing field at present. In this study, the effects of HHP treatment (100~500 MPa for 5 min) on the physicochemical properties, texture parameters, and volatile flavor compounds of oysters were investigated. The results showed that HHP treatment increased the water content while reducing the crude protein and ash content of the oyster. Texture parameters showed that HHP treatment improved the hardness, springiness, chewiness, and cohesiveness of oysters, compared with the control group. In addition, the saturated fatty acid (SFA) content was slightly increased after HHP treatment, while the difference in monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) content was not significant. Furthermore, HHP increased hexenoic aldehyde, 2,4-heptadienal, 1-octene-3-ol, and 2-octen-1-ol and decreased the contents of 3. 6-nadien-1-ol, 3-octanone, and 2-undecanone, suggesting that HHP might inhibit the fishiness of oyster and showed a positive effect on its flavor. Based on the above results, HHP improved the edible qualities such as texture properties and volatile flavor of oysters. This meets the requirements of consumers on the edible quality of seafood and provides new ideas for the development of seafood.

To expand the utilization of oyster protein (OP), the effects of high pressure (100 to 500 MPa) on chemical forces, structure, microstructure, and digestibility properties were investigated. High pressure (HP) treatment enhanced the electrostatic repulsion (from −13.3_Control to −27.8_HP200 mV) between protein molecules and avoided or retarded the formation of protein aggregates. In addition, the HP treated samples showed uniform distribution and small particle size. The changes in electrostatic interaction and particle size contributed to the improvement of solubility (from 10.53%_Control to 19.92%_HP500 at pH 7). The stretching and unfolding of protein were modified by HP treatment, and some internal hydrophobic groups and -SH groups were exposed. HP treatment modified the secondary structure of OP. The treated samples contained less α-helix and β-sheet structures, whereas the proportions of β-sheet and random coil structures were increased. The treated samples have high digestibility in the stomach (from 26.3%_Control to 39.5%_HP500) and in the total digestive process (from 62.1%_Control to 83.7%_HP500). In addition, the total digestive production showed higher percentages of small peptides (<1 kDa) after HP treatment. The protein solubility and digestibility were increased after HP treatment, and high solubility and high digestibility might increase the chance that OP become a kind of protein supplement.