Antioxidant effects of red alga (Gracilaria corticata) ethanol extract on the Shelf-life of Scomberomorus guttatus fish fillet stored at 4 ºC

The antioxidant effects of red algae (Gracilaria corticata) extract on the quality and shelf life of Scomberomorus guttatus fish fillet in three treatments; two concentrations of (A) 300 ppm and (B) 600 ppm of ethanol extract and one control sample immersed in distilled water without any additive was investigated. The samples were stored at refrigerator (4ºC) for 12 days. The measurements were undertaken at 0, 3, 6, 9 and12 days at the beginning of the experiment. The results showed that the total phenolic content and the ability of the red algae extract to preventthe free radicals were 3.74±0.34 mg Gallic acid/g dry weight of extract and 24.7±2.07%, respectively. Generally, thiobarbituric acid (TBA), total volatile base nitrogen (TVN), free fatty acid (FFA) and pH values were significantly increased and lipid content decreased with storage time, whereas the peroxide value )PV( and moisture content increased at the beginning but decreased at the end of the period (p < 0.05). The treatments maintained better quality in comparison to the control group and A treatment had better antioxidant properties and resulted in the longer shelf life of the product.