This study investigated the effects of plasma-activated water (PAW) generated with argon at discharge times of 0, 4, 8, 12, and 16 min on the gel properties and structures of chicken myofibrillar protein (MP). Under treatments of 8, 12, and 16 min, both the gel strength and water retention capacity of MP significantly improved, with the gel strength (0.53 N) peaking at 16 min and the lowest cooking loss（30.38 %）. As the treatment time increased from 0 to 16 min, the storage modulus also gradually increased. Results from low-field nuclear magnetic resonance indicated a slowing of water proton mobility, with the proportion of bound water rising from 0.26 % (0 min) to 0.52 % at 16 min. Fourier transform infrared spectroscopy, endogenous fluorescence spectroscopy and scanning electron microscopy confirmed PAW's alteration of MP's secondary and tertiary structures and gel microstructure. Additionally, this study explored the influence of argon PAW's primary active species on MP from a molecular docking perspective·H2O2 could form hydrogen bonds with MP, while O3 and NO2‾could interact via both hydrogen bonds and electrostatic interactions. Thus, PAW can alter protein structure and enhance MP's functional properties, providing insights for applying cold plasma in processing chicken gel products.
This study appraised the effects of dietary blend of 80% canola oil and 20% palm oil and postmortem ageing on oxidative stability, fatty acids and quality attributes of gluteus medius (GM) muscle in goats. Twenty-four Boer bucks were randomly allotted to diet supplemented with 0, 4 and 8% oil blend, fed for 100 days and slaughtered, and the GM muscle was subjected to a 7 d chill storage (4±1°C). Diet had no effect (P> 0.05) on the colour, drip loss, thiobarbituric acid-reactive substances (TBARS) value, free thiol, carbonyl, myoglobin and metmyoglobin contents, metmyoglobin reducing activity (MRA), antioxidant enzyme activities and abundance of myosin heavy chain (MHC) and actin in the GM muscle in goats. The meat from goats fed 4 and 8% oil blend had higher (P< 0.05) concentration of α and γ-tocopherol and abundance of troponin T compared with that from the control goats. The GM muscle from the oil-supplemented goats had lower (P< 0.05) concentration of C16:0 and greater (P< 0.05) concentration of C18:1n-9, C18:3n-3 and C20:5n-3 compared with that from the control goats. Nonetheless, diet did not affect (P< 0.05) the total fatty acid in the GM muscle in goats. Regardless of the diet, the free thiol and myoglobin contents, concentration of tocopherol and total carotenoids, MHC and MRA in the GM muscle decreased (P< 0.05) while carbonyl content, TBARS, drip loss and metmyoglobin content increased over storage. Dietary blend of 80% canola oil and 20% palm oil beneficially altered tissue lipids without hampering the oxidative stability of chevon.
Yeast extracellular proteases play a key role in developing the taste of dry-cured ham, whereas the mechanism of yeast proteases on taste formation of dry-cured ham is not fully studied. The proteases characteristics of yeast isolated form Jinhua ham, hydrolysis capacities for myofibrillar proteins (MP), free amino acid contents, metabolite compositions, taste parameters and the relationship between metabolites and taste parameters were investigated to reveal the mechanism of Rhodotorula mucilaginosa AUMC 9298 (RM) and Candida parapsilosis d70a (CP) proteases on MP hydrolysis and taste development of dry-cured ham. The proteases of RM and CP showed high hydrolysis activities at the conditions of pH 5.0-8.0 and 30-50 °C. The proteases of RM showed higher capability to degrade myosin compared with CP proteases and Pichia kudriavzevii XS-5 (PK) proteases. The total free amino acid contents increased from 18.44 mg/100 mL in PK to 33.91 mg/100 mL in RM and 25.28 mg/100 mL in CP after 4 h hydrolysis of MP. Thirty-two metabolites were identified by LC-MS/MS, and peptides and amino acid derivatives were the key components of MP hydrolysates. The scores of umami, richness and aftertaste showed the largest values in RM among these groups. PLS-DA and correlation demonstrated that aspartic acid, N-Methyl-aspartic acid, Glu-Glu, γ-Glu-Cys, glutamic acid, γ-Glu-Glu and γ-Glu-Gln were positive correlation with the improvement of umami, richness and aftertaste.