The antibacterial mechanism of compound preservatives combined with low voltage electric fields on the preservation of steamed mussels (Mytilus edulis) stored at ice-temperature

Abstract

Mussels are a kind of economically valuable ocean bivalve shellfish. It has a short harvest period and is susceptible to contamination during storage and processing. Having proper preservation methods is critical to prevent quality deterioration. However, the effect of low voltage variable frequency electric field and compound preservative on the freshness of steamed mussels in ice-temperature storage are still unknown. We utilized the method of coefficient variation weighting to calculate the overall scores of steamed mussels stored under different preservation conditions. The protein physicochemical properties of samples, the growth curves of two dominant spoilage bacteria; Bacillus subtilis and Pseudomonas in the mussels as well as the Structural changes of the cell membranes were mensurated. The results show that compared with the preservative group and the low voltage variable frequency electric field group, the compound preservatives combined with the electric field group had the highest overall score and thus the best preservation effect. Compared with the blank group, the total sulfhydryl content and myogenic fibrin content of the combined group decreased at the slowest rate, 19.46%, and 44.92%, respectively. The hydrophobicity of the protein surface increased by only 5.67%, with the best water retention, indicating that the samples of the combined group had the least protein deterioration in the combined group. The inhibition mechanism of the combined group inhibited the growth of two dominant spoilage bacteria: Bacillus subtilis and Pseudomonas, in the mussels, destroying the integrity of the cell membrane structure and changing the cell morphology. Overall, we found that the combination of the composite preservatives and the low voltage variable frequency electric field can maintain the best quality of steamed mussels during ice-temperature storage and slow down the rate of protein deterioration during storage. This study proposed a new method of mussel preservation, which provides a new idea for the application of low voltage variable frequency electric field and compound preservative in the preservation of aquatic products.