Extraction of flavanone compound from orange peel and evaluation of its antioxidant properties

Antioxidant property of orange peel

Abstract

The experiment was conducted to evaluate the in vitro antioxidant property of crude extract (hesperidin rich extract) prepared from the peel of Mandarin orange (Citrus reticulata). The dry matter recovery of the prepared extract was found to be 1.80 %. The anti-oxidative property of the crude extract was evaluated by using ferric reducing analysis of plasma (FRAP) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays at 5.00, 2.50, and 1.25 mg/ml and compared with pure hesperidin (chemical grade, 80% purity) of similar concentration. FRAP value and DPPH inhibition were positively correlated to the concentration of crude and /or pure hesperidin; exhibiting maximum activities at 5 mg/ml (P<0.05). Hesperidin rich crude extract (HRCE) at 5mg/ml exhibited a significantly higher FRAP value than all the concentrations of pure hesperidin. DPPH inhibition (%) also followed the similar trend (P<0.05). In addition, both antioxidative properties of flavanone compounds (crude and pure hesperidin) were tested in the experimental diets. Five isonitrogenous (32% crude protein) and iso-calorific (333.46 Kcal/100g) diets were prepared using different concentrations of HRCE. The diets were viz. control (0% HRCE), T1 (0.5% pure hesperidin), T2 (1.0 % pure hesperidin), T3 (0.5% HRCE), and T4 (1.0 % HRCE) were evaluated to test their anti-oxidative properties based on FRAP and DPPH assays under in-vitro conditions. The diet containing 1.0 % HRCE (T4) exhibited a significantly higher FRAP value (20.94 mmol Fe2+/g) followed by 1.0 % pure hesperidin (T2), 0.5% HRCE (T3), 0.5% pure hesperidin (T1), and the minimum value was observed in the control diet (P<0.05). FRAP value was higher in treatment groups than the commercial feed (except T1). Similarly, maximum DPPH inhibition was observed in a diet containing 1.0 % HRCE and minimum in the control group. HRCE containing diets exhibited more scavenging properties than the diets containing pure hesperidin at the same inclusion level (P<0.05). Flavanone compounds (mainly hesperidin) containing diets were shown to exhibit more DPPH activities compare to commercial and control diet. Therefore, it can be concluded that the supplementation of crude flavanone extract rich in hesperidin compound improves the anti-oxidative properties of the diets.