Effect of konjac glucomannan-based preservation pads on quality changes in refrigerated large yellow croaker (Pseudosciaena crocea)

The purpose of this study was to evaluate the preservation effects of konjac glucomannan (KGM)/oregano essential oil (OEO) Pickering emulsion-based pads (K/OPE pads) on large yellow croaker (Pseudosciaena crocea) fillets stored at 4 °C. The K/OPE pads were fabricated using a freeze-drying technique. The homogeneous distribution of the OEO Pickering emulsions in the KGM matrix was observed using scanning electron microscopy. Fourier transform infrared spectroscopy confirmed that the OEO emulsions were encapsulated in the KGM and there was hydrogen bonding interaction between them. Compared with the KGM pads, the K/OPE pad groups demonstrated enhanced antioxidant and antimicrobial properties. When the content of OPE was increased from 20 % to 40 %, the antioxidant performance of the K/OPE pads increased from 48.09 % ± 0.03 % to 86.65 % ± 0.02 % and the inhibition range of Escherichia coli and Staphylococcus aureus increased to 13.84 ± 0.81 and 16.87 ± 1.53 mm, respectively. At the same time, K/OPE pads were more effective in inhibiting the formation of total volatile alkaline nitrogen and the production of thiobarbituric acid-reactive substances, thereby helping in reducing water loss and maintaining the muscle tissue structure of fish fillets for a longer storage time. Consequently, these K/OPE40 pads extended the shelf life of the fish fillets by an additional 4 days and delayed spoilage during refrigerated storage. The findings suggest that the K/OPE pads can effectively safeguard the quality of refrigerated large yellow croaker fillets, presenting their potential as an active packaging material in the fish preservation industry.