Suitability of chitosan nanoparticles as cryoprotectant on shelf life of restructured fish surimi during chilled storage

The present study investigated chitosan nanoparticle (CS-TPP NPs) preparation by ionic gelation process with chitosan (CS) and tripolyphosphate (TPP). The structural characterization of nanoparticles was studied using Dynamic Light Scattering, Nuclear Magnetic Resonance, Fourier Transform Infrared (FTIR) and X-Ray Diffraction spectroscopies. FTIR spectra confirmed that the tripolyphosphoric groups of TPP linked with ammonium groups of CS in the prepared nanoparticles. CS-TPP NPs exhibited higher antioxidant activity and an interesting antimicrobial potential. In fact, there was no report available in literature on using CS nanoparticles for the surimi preservation. Further, data revealed that nanoparticle incorporation in fish surimi effectively inhibited thiobarbituric acid substances and conjugated dienes formation, and thereby, retarding lipid oxidation. Results showed that CS-TPP NPs were able to hinder fish surimi myoglobin oxidation with a significant improvement in the transformation of Heme iron. In addition, CS nanoparticles exhibited a distinguishable antimicrobial activity in the stored surimi during cold storage of 9 days. Thus, nanoparticles could be used as a natural ingredient to prevent lipid oxidation in surimi based food systems for the development of novel healthy fish products and addresses consumer demands for functional fish products.