There is currently a great deal of interest in developing neuroprotective peptides to address memory impairment and cognitive decline. Although the shrimp peptide Gln-Met-Asp-Asp-Gln (QMDDQ) has been demonstrated to have neuroprotective activity by cellular assays, the molecular regulatory mechanism in animals remains unclear. In this study, we explored the neuroprotective effects of QMDDQ in mice with scopolamine-induced memory impartment using behavioral tests, tissue staining techniques, proteomics, immunofluorescence, and Western blotting. The results of the study showed that QMDDQ was able to shorten the escape latency, reduce the number of electric shocks, and improve the behavioral performance of mice. The neuronal damage in CA1, CA3 and Dentate Gyrus regions was better repaired, and QMDDQ also increased the content of acetylcholine in the hippocampus with the increase of the gavage dose, and the activity of acetylcholinesterase was inhibited. Proteomics data showed that a total of 62 differential proteins were identified in the model and QMDDQ groups, with KEGG pathway enrichment showed significant changes in 40 pathways such as the cAMP signaling pathway, as verified by the key protein adenylate cyclase 5 (Adcy5). The results suggested that QMDDQ improved synaptic plasticity through the Adcy5/PKA/p-CREB pathway, thus exerting a neuroprotective effect protective effect.

A nutrition package can effectively supplement the lack of nutrients in the daily diet. Lipid oxidation is also prone to occur during storage, due to the high fat content in the nutrition package. The unpleasant odors can be then generated to limit normal consumption. The nitrogen packaging and antioxidants can be added to effectively slow down the oxidation of nutritional supplements, and then inhibit the generation of off-flavors. There are two commonly used methods to inhibit the oxidation of nutrition packages. Gas chromatography-ion migration spectrometry (GC-IMS) has been a new type of rapidly-developed flavor analysis in recent years. The high selectivity of gas chromatography was combined with the high sensitivity of ion mobility spectrometry to achieve the rapid qualitative and quantitative analysis of volatile compounds. In this study, a improved type of basic nutrition package was prepared to add the zeaxanthin and blueberry powder for preschool children. The free radical scavenging of zeaxanthin, blueberry powder, and their combination were evaluated using an electron spin resonance (ESR), in order to assess their antioxidative properties. GC-IMS was utilized to analyze the deterioration of flavor quality of nutrition packages after accelerated storage. The nutrition packages were rapidly identified to reveal the differences between volatile compounds in different formulations. The results showed that the combination of zeaxanthin and blueberry powder exhibited higher free radical scavenging. Meanwhile, the nutrition package with the improved formula shared lower levels of free radicals, compared with the basic one after accelerated storage. Therefore, the zeaxanthin and blueberry powder were added to inhibit the increase of free radicals. The flavor fingerprints were established for two formulations of the nutrition packages in accelerated storage for 0 and 300 days. A total of 71 volatile compounds were identified, including 15 alcohols, 13 aldehydes, 6 ketones, 5 alkenes, 2 phenols, 15 esters, 2 sulfides, 1 hydrocarbon and 12 heterocycles. There were differences in the volatile compounds after storage of different formulations of nutrition packages. The zeaxanthin and blueberry powder dominated the flavor of the nutrition package. Methyl salicylate and ethyl acetate shared the flavor properties of blueberry, indicating a rich floral and fruity aroma to the nutrition package. 6-Methyl-5-hepten-2-one and terpinolene were identified as the characteristic flavor compounds of carotenoids, indicating the aroma of lemongrass and pine. The levels of these compounds in the improved formula nutrition package were higher than those in the basic one. As such, the zeaxanthin and blueberry powder had enriched the flavor of the nutrition package. The addition of zeaxanthin and blueberry powder reduced the levels of volatile compounds (E, E)-2,4-hexadienal, 2-methyl-3-furanthiol, ethylpyrazine, (E)-2-heptenal, (E)-2-hexenal produced from fat oxidation, oleic acid, linoleic acid, and Maillard reaction after accelerated storage. In addition, there was a higher content of aromatic volatile compounds, such as cis-4-decenal, 3-methyl-2-butenal and linalyl acetate in the improved formula nutrition package, indicating the protective effect on the flavor in the nutrition package. Heat maps and principal component analysis showed that the types and amounts of volatile compounds were clearly distinguished in the nutrition packages of the two formulations. In conclusion, the zeaxanthin and blueberry powder can be expected to inhibit the generation of off-flavors in nutrition packages, in order to regulate the deterioration of flavor quality during storage. The findings can provide a theoretical basis for the better flavor quality of the nutrition package.

This paper aimed to explore the mechanism of tetrapeptide Val-Thr-Pro-Tyr (VTPY) in improving alcoholic gastric injury. VTPY has the potential to enhance the growth and movement of normal human gastric epithelial cells (GES-1). Following ethanol-induced impairment, VTPY effectively improved migration of GES-1 and human umbilical vein endothelial cells (HUVEC) cells, enhanced angiogenesis, eliminated cellular and mitochondrial reactive oxygen species (ROS), inhibited excessive mitochondrial division, enhanced F-actin polymerization and mitochondrial respiratory capacity. To counteract excessive mitochondrial fission, VTPY primarily restores the mitochondria dynamics by reducing the expression of Drp1 and Fis1, while increasing Mfn2. Further studies utilizing inhibitors clarifies that the inhibition of excessive mitochondrial fission can markedly reduce F-actin depolymerization, consequently enhancing cell migration. Additionally, VTPY can inhibit the apoptosis pathway by maintaining potential of mitochondrial membrane, preventing the release of mitochondrial cytochrome c, bolstering the levels of Bcl-XL, while reducing the levels of Bax and cleaved-caspase-3. Further investigations using inhibitors demonstrates that excessive mitochondrial fission could activate apoptotic pathway. However, VTPY counteracts this effect and enhance cells viability. Further evidence suggests that VTPY effectively improves ulcer index and pathologic changes, relieves inflammation, enhances the balance of oxidation and anti-oxidation, promotes angiogenesis, improves the expression of mitochondrial dynamics factors, blocks apoptotic pathway, and subsequently ameliorates gastric damage in mice through Fis-1/Bcl-2 pathway.

In this study, the effects of the extracts from mulberry leaves, rosemary, cinnamon, grape seeds, green apples and cloves on the color, oxidative stability and flavor characteristics of oil-fried shiitake mushroom were investigated. It was found that these natural extracts improved the brightness of oil-fried shiitake mushroom and significantly inhibited its browning. The content of melanoid, the Maillard reaction product, was decreased by treatment with each of the extracts, which shared a similar trend with the change in the degree of browning. The natural extracts also significantly improved the antioxidant capacity and inhibited the oxidation reaction of oil-fried shiitake mushroom. Clove extract resulted in the largest decrease in peroxide value (74.36%), while green apple extract resulted in the greatest decrease in thiobarbituric acid reactive substances (TBARS) value (17.54%). Clove, rosemary and grape seed extracts significantly inhibited protein oxidation. Treatment with green apple extract minimized the free radical content. The umami and saltiness were significantly increased by treatment with clove, rosemary or mulberry leaf extract. All six natural extracts increased the levels of nitrogen and oxygen compounds, hydrocarbons, alcohols, aldehydes, and ketone. Seventeen differential volatile compounds, such as methyl 2-methoxybenzoate and isoamyl 2-methylbutyrate, were identified among the six treatment groups and the control group. These results provide a theoretical basis for the application of natural extracts in oil-fried edible mushrooms.

Enzymatic hydrolysis, isolation, and purification might make a great deal of difference in antioxidant activity and antigenicity of peptide components. This study aimed to isolate and purify antioxidant peptide components from Antarctic krill and evaluate their allergenicity of them. Electron paramagnetic resonance (EPR) spectroscopy results indicated 310 kDa Antarctic krill hydrolysates (AKHs) had higher DPPH and ·OH radical scavenging rates. And the second component (N2-2) purified 310 kDa hydrolysate showed better ability to scavenge DPPH and ·OH radicals (P < 0.05), which were (47.43 ± 2.18)% and (34.33 ± 1.25)%, respectively. Additionally, indirect-ELISA results revealed that N2-1 had a weaker ability to bind specific IgE and that N2-2 had a lower binding capability to specific IgG1 (P < 0.05). And N2-2 had a higher EC₅₀ value of (5.29 ± 0.95) ng/mL (P < 0.05) in cell degranulation assay, which was about 13.80 times that of Antarctic krill. Therefore, N2-2 might be the potential source of the antioxidant peptides with lower allergenicity.