Weiliang Guan’s research while affiliated with Guangxi University and other places

Hyperuricemia arises from imbalanced uric acid metabolism, contributing to gout and related chronic diseases. When traditional drugs are used to treat hyperuricemia, side effects are inevitable, which promotes the exploration of new bioactive compounds. Protein hydrolysates and peptides are gradually showing potential in the treatment of hyperuricemia. This study investigated the uric acid inhibitory activity of peptides extracted from Trachurus japonicus using in silico and in vitro methods. We employed in silico virtual enzymolysis and experimental validation to identify bioactive peptides from Trachurus japonicus proteins. Four peptides (DF, AGF, QPSF, and AGDDAPR) were comprehensively screened by molecular docking and database analysis. After solid-phase synthesis, the inhibitory effects of these peptides on hyperuricemia were further verified in vitro and at the cellular level. The results showed that all four peptides have good hyperuricemia-inhibiting activities. Molecular docking and molecular dynamics revealed that peptides DF and AGDDAPR affect the production of uric acid by binding to the active sites of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), and xanthine oxidase (XOD), while peptides QPSF and AGF mainly influence the XOD active site, confirming that it is feasible to rapidly screen hyperuricemia-inhibiting peptides by molecular docking.

Water-free transportation (WFT) causes shrimp (Penaeus vannamei) flesh quality deterioration. However, the roles of endogenous protease-induced protein hydrolysis have been neglected in the research. In the present study, calpain zymography, gelatinase zymography, the hematoxylin–eosin staining method, and other methods were applied to investigate the response of various endogenous proteases (cathepsin, calpain, and gelatinase), the myofibril fragmentation index (MFI), and the microscopic morphology of shrimp muscle during WFT in comparison with the shrimp under the conventional water transportation strategy (WT). The results showed that the total activity of proteases in shrimp muscle increased significantly (p ≤ 0.05) after simulated transportation. Cathepsins and gelatinases were activated during WFT. No significant (p > 0.05) changes of the activity of caspase-3 and the muscle cell apoptosis rate were detected in shrimp muscle cells after WFT. In addition, the MFI increased and the gap among muscle fiber bundles enlarged after WFT. Compared with WFT, no significant (p > 0.05) effect on the activities of calpain, gelatinase, and caspase-3 in the muscle of shrimp was found after WT, and only the activity of cathepsin L significantly increased (p ≤ 0.05). Based on the findings, we concluded that the activation of various endogenous proteases was induced during WFT.

Efficient thawing can preserve the quality of frozen hairtail (Trichiurus lepturus) close to that of fresh hairtail. In contrast to air thawing (AT) and radio-frequency thawing (RT), this study looked at how graphene oxide (GO) and graphene magnetic (GM) nanoparticles paired with RT affect the microstructure and protein conformation of hairtails after thawing. The results suggested that GM-RT can reduce the myofibrillar protein (MP) damage and be more effective than other thawing treatments, like AT, RT, and GO-RT, in maintaining the microstructure of hairtail. The particle size and zeta potential showed that GM-RT could reduce the aggregation of MP during the thawing process compared to other thawing methods. Moreover, the texture of the hairtail after GM-RT exhibited higher hardness (1185.25 g), elasticity (2.25 mm), and chewiness (5.75 mJ) values compared to other thawing treatments. Especially compared with RT, the GM-RT treatment displayed significant improvements in hardness (27.24%), a considerable increase in springiness (92.23%), and an increase in chewiness (57.96%). GO-RT and GM-RT significantly reduced the centrifugal loss. The scanning electron microscopy results demonstrated that the effect of GM-RT was more akin to that of a fresh sample (FS) and characterized by a well-organized microstructure. In conclusion, GM-RT effectively diminished the MP aggregation and improved the texture of thawed fish. It can be regarded as a viable alternative thawing technique to enhance MP stability, which is vital for preserving meat quality.

A new fermentation method for kiwi wine was explored by developing the well-known medicinal and edible plant Cyclocarya paliurus (C. paliurus) to create more value with undersized kiwifruits. In this study, the changes in bioactive substances during the C. paliurus–kiwi winemaking process were analyzed on the basis of response surface optimization results, and the antioxidant capacity, aromatic compounds, and sensory quality of the C. paliurus–kiwi composite wine with kiwi wine and two commercial kiwi wines were compared. The results showed that DPPH radical, OH⁻ radical, and ABTS⁺ scavenging rates remained at over 60.0%, 90.0%, and 70.0% in C. paliurus–kiwi wine, respectively. The total flavonoid content (TFC) and total polyphenol content (TPC) of C. paliurus–kiwi wine were significantly higher than those of the other three kiwi wines. C. paliurus–kiwi wine received the highest score and detected 43 volatile compounds. Ethyl hexanoate, which showed stronger fruity and sweet aromas, was one of the main aroma components of C. paliurus–kiwi wine and different from commercial wines. This wine has a good flavor with a natural and quality feeling of C. paliurus–kiwifruit extract, low-cost processing, and great market potential.

Oxidation of lipid and protein is a major reason of flesh quality deterioration during storage. In this work, cold storage (CS) and flake ice (FI) storage, as traditional strategies for live shrimp (Litopenaeus vannamei) sedation and refrigerated storage, showed remarkable oxidation damage of lipid and protein in shrimp flesh during storage. In contrast, ice slurry (IS), with good heat exchange capacity and contactability, stunned shrimp in a sudden and thus relieved antemortem stress, which resulted in reducing the reactive oxygen species and reactive nitrogen species accumulation, and the oxidation damage risk in flesh. Additionally, IS, as a storage medium acted an oxygen barrier, further inhibited the oxidation of lipid and myofibrillar protein (MP), as revealed by the lower thiobarbituric acid reactive substances level, carbonyl (CO) derives content, total disulfide bond (S–S) content, and the higher total sulfhydryl (SH) content in shrimp flesh during storage, compared with CS and FI. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis electrophoretogram pattern of MP also suggested better preservation of myosin heavy chain, myosin light chain, actin, and tropomyosin in IS, whereas these proteins degraded in CS and FI. Consequently, IS prevented the formation of cross‐linking caused by oxidation in MP, leading to improved shrimp flesh quality during refrigerated storage, as demonstrated by the better maintained hardness, springiness, and water‐holding capacity compared to CS and FI.