Background: Ultrasound can increase the mass transfer between preservatives and food, and enhances the effect of preservatives on food. Chitosan-grafted-chlorogenic acid (CS-g-CA) is a new synthetic compound with good antiseptic properties. Therefore, the present study evaluated the preservation performance of ultrasound-assisted CS-g-CA (GUA) coatings on refrigerated sea bass fillets in terms of changes in microorganisms, lipids, proteins, tissue structures, and moisture.
Results: The results showed that GUA treatment effectively inhibited the growth of microorganisms in sea bass fillets. Meanwhile, the changes in total volatile basal nitrogen, thiobarbituric acid reactive substances, and pH values were all slowed down under GUA treatment, indicating that protein degradation and lipid oxidation in sea bass were inhibited. Low-field nuclear magnetic resonance and magnetic resonance imaging results indicated that the GUA retarded the conversion of mobile water to free water. In addition, GUA treatment maintained the flavor quality of fish fillets, and also inhibited the reduction of inosine monophosphate and the production of bitter substances (inosine and hypoxanthine), suppressed muscle tissue degeneration, and maintained better sensory scores.
Conclusion: Overall, GUA treatment inhibited microbial growth, protein degradation, lipid oxidation, moisture migration, decomposition of umami substances, and deterioration of sensory quality in sea bass fillets. Finally, the shelf-life of sea bass fillets with GUA treatment was extended by an additional 9 days. The results showed that ultrasonic assistance further enhanced the effect of preservatives on aquatic products. © 2022 Society of Chemical Industry.
Keywords: chitosan-grafted-chlorogenic acid; preservation; quality; sea bass; ultrasound.
© 2022 Society of Chemical Industry.