Effects of green tea (Camellia sinensis) and guava (Psidium guajava) extracts on the quality of snakehead (Channa striata) fillets during ice storage

The antioxidant and antimicrobial properties of Camellia sinensis and Psidium guajava leaf extracts were determined and applied as soaking solutions for snakehead (Channa striata) fillets prior to 12-day ice storage. The scavenge 50% of the DPPH (2,2MODIFIER LETTER PRIME-diphenyl-1-picrylhydrazyl) free radicals (IC50) of C. sinensis was 7.63 mu g/mL and 5.04 mu g/mL for P. guajava extract. The minimum inhibition concentrations (MIC) of C. sinensis and P. guajava against Aeromonas hydrophila were 625 and 313 mu g/mL, respectively. The IC50 and MIC concentrations were then applied as extract solutions for soaking snakehead fillets before ice storage. During ice storage, snakehead fillets treated with plants extracts showed reduced lipid oxidation, inhibited bacteria growth, and enhanced sensory properties compared to untreated samples. Based on the total viable count, shelf life of snakehead fillets treated with C. sinensis and P. guajava extracts can be prolonged up to 8 days while less than 8 days for the control treatment. Novelty impact statement In order to maintain the quality of fish products during storage, many preservation methods and techniques are commonly used, where the use of chemicals can directly affect human health. The use of natural preservatives is a promising method that could be an alternative to synthetic additives. In this study, C. sinensis and P. guajava extracts showed significant in vitro antibacterial and antioxidant properties, and therefore have high potential as an agent for ice storage of snakehead fish fillets.