Ionic strength-mediated protein and flavor studies on thermally processed hairtail pieces.

This study aimed to investigate the impact of different ionic strengths on the texture, protein, and flavor of thermally processed hairtail pieces. Incorporating salt ions into the heat treatment process had a positive impact on the quality of the cooked hairtail pieces. The pieces treated with 2 M NaCl showed superior texture and sensory scores. The ionic strength had a significant positive correlation with the chewiness and cohesion of cooked hairtail (p < 0.01). Furthermore, the myofibrillar protein content and total sulfhydryl content increased significantly. Circular dichroism spectra analysis revealed a transition in the protein structure from a ß-sheet structure to an α-helical structure as the ionic strength decreased. The ionic strength had a significant impact on the interaction between protein and flavor compounds. Specifically, it impacted the expression of certain volatile components (p < 0.05). Our study suggests that selecting the appropriate cooking method is crucial for both healthiness and sensory quality of processed hairtail products, and ionic strength mediation is superior in both aspects.

Enhancing the AI-2/LuxS quorum sensing system in Lactiplantibacillus plantarum: Effect on the elimination of biofilms grown on seafoods.

The biofilm clustered with putrefying microorganisms and seafood pathogens could cover the surface of aquatic products that pose a risk to cross-contaminating food products or even human health. Fighting biofilms triggers synchronous communication associated with microbial consortia to regulate their developmental processes, and the enhancement of the quorum sensing system in Lactiplantibacillus plantarum can serve as an updated starting point for antibiofilm-forming strategies. Our results showed that the exogenous 25 mM L-cysteine induced a significant strengthening in the AI-2/LuxS system of Lactiplantibacillus plantarum SS-128 along with a stronger bacteriostatic ability, resulting in an effective inhibition of biofilms formed by the simplified microbial consortia constructed by Vibrio parahaemolyticus and Shewanella putrefaciens grown on shrimp and squid surfaces. The accumulation of AI-2 allowed the suppression of the expression of biofilm-related genes in V. parahaemolyticus under the premise of L. plantarum SS-128 treatment, contributing to the inhibition effect. In addition, strengthening the AI-2/LuxS system is also conducive to eliminating preexisting biofilms by L. plantarum SS-128. This study suggests that the enhancement of the AI-2/LuxS system of lactic acid bacteria enables the regulation of interspecific communication within biofilms to be a viable tool to efficiently reduce and eradicate potentially harmful biofilms from aquatic product sources, opening new horizons for combating biofilms.

Effects of environmental pH on protein properties and flavor factors of hairtail (Trichiurus haumela) in thermal processing.

The flavor and texture of hairtail (Trichiurus haumela) products easily change depending on the processing conditions including the programed temperature, environmental pH, and so on. In the present study, we aimed to explore the differences in the overall texture and flavor of hairtail under heat treatment with varied environmental pH. The results indicated that the secondary structure of the myofibrillar protein in thermal processed hairtail meat presented a transformation from α-helix to ß-sheet structure with the decrease of solution pH. Moreover, heat treatment in an acidic solution environment effectively improved the sensory and flavor properties of hairtail. In addition, pH-mediated changes on protein characteristics of cooked hairtail meat showed significant correlation with the texture properties, while weakly correlated with the flavor.