Preparation of bio-functional surimi gel incorporation of fish oil and green tea extracts: Physico-chemical activities, in-vitro digestibility, and bacteriostatic properties

This study investigates the interaction of fish oil-protein and phenolic-rich green tea extract on the physicochemical quality, lipid oxidation and bacteriostatic properties of different treatments of surimi gel incorporated with fish oil (FO) and Pseuderanthemum palatiferum freeze-dried powder (PFP). The incorporation of 3-6% FO, and 100-200 mg PFP/100 g surimi were investigated. The effect of PFP on the FO-fortified surimi gel had a positive effect on the textural and bio-potential properties. FO-PFP samples showed a higher water-holding capacity than the control gel. Fourier transform infrared spectroscopy (FT-IR) analysis of the surimi gel confirmed the successful blending of oil-protein and phenolic compounds present in PFP. The antioxidant activity and oxidative stability of PUFA-enriched oil increased with the addition of FO-PFP; moreover, the addition of PFP showed good antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Listeria monocytogenes. Hence, the combination of small amounts of PFP in oil-emulsified surimi gel could help in obtaining good-quality surimi gel fortified with health-beneficial polyunsaturated fatty acids that have antibacterial properties.