Qixing Jiang’s research while affiliated with Jiangnan University and other places

This study investigated the effect of five different reheating methods (boiling water, steaming, low‐heat microwave at 120 W, medium‐heat microwave at 400 W, high‐heat microwave at 800 W) on lipid oxidation of silver carp fish cake. The changes of lipid content, thiobarbituric acid (TBA) value, acid value (AV), peroxide value (POV), volatile flavour components and fatty acid composition were detected. The results indicated that products reheated with medium‐heat microwave had higher lipid content, lower TBA, AV and POV value. The medium‐heat and high‐heat microwave reheated group had larger variety of volatile flavour substances. Moreover, the relative content of hexanal and heptanal related to unpleasant “overcooked taste” was less, and the relative content of 2‐heptanone, which contributed to the reduction of fishy odour, was more in medium‐heated microwave group. The content of monounsaturated fatty acids in the medium‐heat microwave group was higher than other reheating methods, so as the ratio of unsaturated to saturated fatty acids. Considering all indicators, medium‐heat microwave reheating is more recommended due to its inhibition of fat oxidation.

This study aimed to investigate the interaction between 2‐phenylethanol (2‐PE) signalling molecule and volatile flavour compounds, as well as how 2‐PE would affect Saccharomyces cerevisiae 31 (Sc 31) growth and metabolism. Succession of 2‐PE in sour fish with and without Sc 31, as well as volatile flavour compounds, and its influence on cell morphology in yeast extract peptone dextrose (YPD) medium were determined. Spearman showed that the content of 2‐PE had a positive correlation with inoculated Sc 31 (r = 0.785), esters (r = 0.885), and alcohols (r = 0.758). Moreover, Sc 31 growth rate was positively impacted by 2‐PE up to 500 μm in YPD medium. This could significantly increase the production of biofilm (P < 0.05) and also partially damage the cell wall and membrane. As a result, 2‐PE might affect exchange of substances between Sc 31 and the environment, which could promote the flavour generation during fermentation.

BACKGROUND The gelation properties of surimi gel under various high temperatures (115, 118, and 121 °C) and sterilization intensities (F0 values of 3–7 min) were systematically investigated. A kinetic model detailed quality changes during heat treatment through mathematical analysis, elucidating mechanisms for gel quality degradation. RESULTS Increased sterilization intensity significantly reduced the quality characteristics of surimi gel. Compared to the gel without sterilization treatment, when the sterilization intensity was increased to 7 min, the gel strength of the groups treated at 115 °C, 118 °C, and 121 °C decreased by 68.35%, 51.4%, and 51.71%, respectively, and the water‐holding capacity decreased by 24.87%, 16.85%, and 22.5%, respectively. The hardness, chewiness, and whiteness of the gel also significantly decreased, and the changes in these indicators all conformed to a first‐order kinetic model. Activation energy of 291.52 kJ mol⁻¹ highlighted gel strength as the least heat‐resistant. At equivalent sterilization intensities, 115 °C exhibited the poorest gel quality, followed by 121 °C, with 118 °C showing relatively better gel quality. Increased T22 and decreased PT22 suggested heightened water mobility and transition of immobilized water within the gel into free water. Protein degradation, weakened disulfide bonds and hydrophobic interaction, and protein conformation changes collectively led to a rough and incoherent gel network structure with large fissures, as verified by the results of scanning electron microscopy. Correlation analysis indicated potential for precise control over surimi gel quality by modulating physicochemical attributes. CONCLUSION The outcomes may be beneficial to improve the production and quality control of ready‐to‐eat surimi‐based products. © 2024 Society of Chemical Industry.

Brown stain is a major problem for tuna during storage. This study aimed to investigate the impact of antioxidants on myoglobin oxidation and the promotion of metmyoglobin (MetMb) reduction in tuna slices. Response surface methodology (RSM) was used to optimise the formula of the compound antioxidant in yellowfin tuna (YFT) slices, with the percentage of MetMb as the response value. The ratios of ε‐polylysine, sodium lactate and D‐sodium ascorbate were 0.43%, 2.21% and 2.71%, respectively. The interactions between sodium lactate and D‐sodium ascorbate had a greater impact on the percentage of MetMb. Then, verification experiments were conducted, and the results revealed that the samples treated with compound antioxidants had higher a* values, total sulfhydryl content, Ca²⁺‐ATPase activity, total reducing activity (TRA) and MetMb‐reducing activity (MRA) and lower percentages of MetMb and carbonyl contents than did the control samples. It also helps to maintain the stability of the NADH/NAD⁺ ratio, which contributes to facilitating MetMb reduction. The results showed that the compound antioxidant significantly inhibited myoglobin oxidation, promoted the reduction of MetMb in tuna slices and significantly enhanced the myoglobin stability of refrigerated YFT slices.