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The food's perishable properties and people's eco-friendly requirements have driven the biodegradable active packaging development. In this study, modification behaviors of polyviniyl alcohol/hydroxypropyl methylcellulose/roselle anthocyanin-based (PHR) film on textural profiles of Penaeus vannamei were investigated. Shrimp samples were packaged by PHR film with different roselle anthocyanin contents and stored at 4 ± 1 °C. The results indicated that PHR groups exhibited better texture with higher values of hardness (435.56 ± 75.52 g), springiness (0.53 ± 0.04 mm), chewiness (198.83 ± 40.98 N) and resilience (0.45 ± 0.04). The PHR film exerted positive influences on water migration by reducing drip loss and promoting conversion of free water into immobilized water. Meanwhile, the PHR film retarded protein denaturation via increasing myofibrillar protein and sulfhydryl group contents, decreasing TCA (trichloroacetic acid)-soluble peptide contents and maintaining protein secondary structure (higher α-helix ratio and lower β-sheet ratio). In conclusion, the PHR film improved shrimp texture by rearrangement of water distribution and stabilization of protein conformation. Hence, the PHR film was a novel potential active packaging for shrimp texture enhancement. • The modification behavior and mechanism of PHR film on texture were illuminated. • Water distribution and protein conformation affected textural profiles together. • The PHR film had potential in rearranging water migration positively. • The PHR film was able to delay protein denaturation and stabilize protein structure. The PHR film was a novel food package in texture enhancement and food preservation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel antioxidant peptide was isolated and identified by chromatography, HPLC and LC-MS/MS. • The antioxidant stability of peptide was determined under in vitro digestion model. • The effects of peptide on oxidative damage HepG2 cells induced by H 2 O 2 were determined. • The reasons of antioxidant effect on cells were analyzed by combining peptide sequence and Keap1-Nrf2-ARE pathway. Antioxidant peptide, referred as Trp-Gly-Pro-Gly-Val-Glu (WGPGVE), was isolated and identified from porcine plasma which was hydrolysised 5 h by alkaline protease. The sequence of WGPGVE had hydrophobic amino acids G, V, aromatic amino acids W, and acidic amino acid E, as well as its values of hydroxyl, ABTS, DPPH radicals scavenging rates and iron chelating rate were improved by 30.15%, 10.05%, 38.69%, 51.40% respectively, compared to glutathione (29.32%, 81.06%, 25.43%, 17.82%). Moreover, under in vitro digestion model, it exhibited stable antioxidation (50.15%, 92.49%, 24.29%, 35.35%) after the hydrolysis effect of pepsin and trypsin. Additionally, WGPGVE could protect HepG2 cells against H 2 O 2 by promoting the expression of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and decreasing reactive oxygen species (ROS), malondialdehyde (MDA) contents. Thus, the new sequence antioxidant peptide could be potentially used in pharmaceuticals or functional foods and promote the application of porcine plasma in food. [ABSTRACT FROM AUTHOR]

To understand the nutritional characteristics of new species of Nepture volute (NV), its meat is used for nutritional analysis. NV had about 10% proteins containing essential amino acids except for tryptophan, 0.2% lipids containing 70% unsaturated fatty acids, 0.1% hydroxy acids with the function of fat reduction, 0.07% Ca, 0.002% Fe, 0.001% Zn. NV protein (NVP) with histone 3, perivitelline, cytochrome oxidase subunit played important role of cellular component, molecular functions and biological process in NV cells metabolism. Moreover, salt-soluble and acid-soluble proteins dominated NVP, suggesting high gel forming ability and small molecular weight. NVPs were pseudoplastic fluid (n < 0.2 in Power law), exhibiting shear thinning. Moreover, high rate of α-helix: β-sheet in NVPs led to more than 50% protein digestibility, 70% amino acids digestibility, 80% protein and trace elements absorption rates. NV also had antioxidant function (DPPH scavenging rate 23.289%) after digestion due to the presence of aromatic (phenylalanine) and acidic amino acids (aspartic acid, glutamate). Thereby, NV could complement multiple nutrients and had potential anti-oxidation and weight-losing functions. • Nutrients of Nepture volute (NV) including proteins, lipid, trace elements (Ca, Fe, Zn) were determined. • The NV proteins (NVP) properties (structure, rheology, thermal stability) were determined. • The NVP types and functions were analyzed based on proteomics. • Antioxidation and digestion/absorption rates of NV nutrients were analyzed by in vitro digestion/caco-2 cells model. [ABSTRACT FROM AUTHOR]