QUANTIFICATION OF TOTAL PHENOLICS AND EVALUATION OF THE ANTIOXIDANT ACTIVITY OF FISH DIETS SUPPLEMENTED WITH LYCHEE PEEL FLOUR

Recent studies have shown that the use of fruit and vegetable residues as sources of bioactive compounds have been essential in the prevention and treatment of chronic diseases. The objective was to evaluate the content of total phenolic compounds and the antioxidant capacity of the aqueous extract of different concentrations of lychee peel flour added to the zebrafish diet. Two diets were formulated with variation in the addition of corn starch content. The fish were divided into five groups, and lychee peel flour was added to the HC diet (high starch content) in different concentrations (2%, 4% and 6%). To obtain the extract, 1 g of the feeds (Control, HC, HC2%, HC4%, and HC6%) was weighed into 10 mL of distilled water. The samples were transferred to the ultrasonic bath and kept for 30 minutes. For the determination of total phenolic compounds the Fast Blue method was used. The antioxidant activity was determined by ABTS+, DPPH- and β-Carotene/Linoleic acid tests. The control diet differed statistically from HC4% and HC6% (p<0.001) in total phenolic compounds content. Regarding the antioxidant activity assays, in the ABTS+ assay there was a statistical difference only between the control diet and HC6% (p=0.0052). As for the DPPH- radical, statistical significance was observed between the control diet and HC4% (p=0.0002) and HC6% (p=0.0011). In the β-Carotene/Linoleic acid methodology there was no statistical significance between treatments. It is possible to suggest that through the tests performed the lychee peel flour has exerted the expected beneficial effects during the period that the zebrafish were fed, mainly due to its biological properties already elucidated in the literature. Thus, it is concluded that the diets HC4% and HC6% were able to hold the highest contents of total phenolic compounds and total antioxidant capacity by the tested methods.