內(nèi)容: Biopolymer complexes fabricated by proteins and neutral polysaccharides have some specific and innovative functionalities. A better understanding of the interactions among these biopolymers might provide new insight into the applications of the complexes. Therefore, this study aimed to investigate the structural characteristics and molecular interaction mechanisms of whey protein isolates (WPI) and?Auricularia auricular?polysaccharides (APs). The turbidity analysis confirmed that the pH value and mixing ratio of the two polymers had strong effects on the formation of the APs-WPI complexes. All dispersions formed soluble complexes at approximately pH = 6.0 (pHc). APs-WPI self-assembles exhibited physically cross-linked networks under higher APs proportions, while they formed spherical complexes at higher WPI ratios. The addition of APs could alter the secondary structure of WPI, and the most noticeable changes were located in the regions of?β-sheet and?β-turn as confirmed by circular dichroism (CD) analysis. A molecular docking study showed that the amino acid residues of?β-lactoglobulin complexed with the –COOH and –OH groups of APs. Hydrogen bonds and hydrophobic interactions, which were nonbonding contributions, played a key role in the formation of the APs-WPI complex. This study provided a basis for the development and application of APs in WPI-based beverages.

內(nèi)容: Related research findings indicated that the hardness of the tail meat from red swamp crayfish (Procambarus clarkii) increased when responding to cold stress during the transportation. However, the effect of low temperature on crayfish muscle was still at the phenotype level, there were few studies on the molecular mechanism of crayfish muscle response to cold stress. The effect of cold stress on the tail meat of crayfish during simulated transportation (control and low temperature stress for 12 h (LT_12), 24 h (LT_24) and 36 h (LT_36) at 4 ℃) were investigated by integrated transcriptome and proteomics. The results showed that the hardness of crayfish meat increased after cold stress. Gene ontology (GO) analysis showed that differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) of crayfish coping with cold stress were mainly involved in metabolism and glycolysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic analysis found that the metabolic response to cold stress included changes in amino acids such as valine and isoleucine. Low temperature activated glycolysis and amino acid metabolism pathway as well as peroxisome pathway to maintain body balance. The significant increase in the expression of cytoskeletal protein-actin related genes such as?β-actin and ACT1 might cause the increase of muscle hardness under stress.