Effects of soluble Antarctic krill protein-curcumin complex combined with photodynamic inactivation on the storage quality of shrimp.

A new protein complex (SAKP-Cur) was successfully prepared by combining soluble Antarctic krill protein with curcumin through hydrophobic action. The potency of photodynamic inactivation (PDI) mediated by the complex on preserving the storage quality of shrimp at 4 °C was investigated by microbiological, chemical, physical and histological methods. Results showed that the SAKP-Cur significantly improved the stability of curcumin, and greatly inactivated the native bacteria in shrimp driven by PDI. Meanwhile, the complex-mediated PDI effectively reduced the endogenous enzyme activity, the production of total volatile basic nitrogen (TVB-N) and malondialdehyde (MDA) in shrimp. Moreover, it obviously maintained the integrity and elasticity of the muscle fibers, thereby reducing the loss of water in myofibrils. Notably, the SAKP-Cur enhanced the PDI potency to preserve the freshness of shrimp during 4 °C storage or freeze-thaw cycles treatment. Therefore, the SAKP-Cur coupled with PDI is an effective fresh-keeping technology for aquatic products.

Basic electrolyzed water coupled with ultrasonic treatment improves the functional properties and digestibility of Antarctic krill proteins.

This study firstly constructed a new method of basic electrolyzed water coupled with ultrasonic (USBEW) to creatively modify the Antarctic krill proteins (AKPs), and its effects on amino acid composition, structural and functional properties, as well as in vitro digestibility of AKPs were evaluated. Results showed that BEW inhibited the production of 1O2 and •OH radicals from ultrasonic treatment. In comparison with the deionized water coupled with ultrasonic (USDW) treatment, the USBEW treatment effectively reduced the oxidation of active groups (carbonyl and free sulfhydryl) in the side chain of amino acids of the AKPs, and it also obviously decreased the particle size (18.6 nm), improved the solubility (13.2 %), increased the molecules flexibility and the surface hydrophobicity of AKPs. All these advantageous changes contributed to the improved foam stability, foam capacity and emulsifying properties of AKPs. More importantly, the in vitro digestibility (84.6 %) of AKPs treated by USBEW was significantly higher than that any control samples. Our results prove that the USBEW treatment is a valid and promising method to exploit novel marine protein products with a high nutritional quality.