COMPARATIVE STUDY ON BIOCHEMICAL AND ANTIOXIDANT ACTIVITIES OF TWO APPLE VARIETIES GROWN IN ALGERIA

The aim of this study was to evaluate the physicochemical properties of two apple varieties, Golden delicious (GD) and Royal Gala (RG) from the Arris region of Algeria. In addition, these two apple varieties were examined for their composition of bioactive compounds and their antioxidant activity. Color differences were also studied. Concerning physicochemical parameters, both apple varieties have almost the same water content (86.12-86.30%), but in parallel, they showed significant differences (p ≤0.05 %) for pH, brix, total sugars, reducing sugars and ash. For polyphenols, the RG apple is twice as rich (85.82 mg EGA/100g) compared to the GD (39.36 mg EAG/100g), while the GD variety is rich in flavonoids with significant differences. As a result, the RG apple showed higher antioxidant activities (DPPH, FRAP and beta-carotene bleaching) than GD. Strong correlations were recorded between polyphenol content and antioxidant activities. In terms of color, the lightness (L*) and yellowness (a*) of GD apple were significantly higher than those of RG apple, reflecting the pigments present in each variety.