Evaluation of antioxidant properties of Monodora tenuifolia on cooked beef and pork

Abstract

This study evaluated the phytochemical composition and antioxidant properties of a Nigerian spice, Monodora tenuifolia seeds. Milled seeds was extracted with five different solvent systems and screened for total phenol (TP), condensed tannin (CT), total flavonoid (TF) and total anthocyanin (TA) contents using standard methods. Spice antioxidant capacities to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, reduce iron (iii) chloride (FeCl₃) and inhibit lipid peroxidation in cooked, refrigerated (4^OC, 14 days) beef and pork patties were investigated. Solvent systems significantly (p < 0.05) influenced the amounts of each phytochemical extracted. Spice had high contents of TP (0.21 – 15.93 GAE /100g) but relatively low content of anthocyanin (0.00 – 0.05 GAE /100g). Methanol (95%) was the best extracting solvent for the phytochemicals. TP contents (GAE/100g) ranged from 2.61in acetone/hexane to 6.78 in 95% methanol. Spice suppressed lipid peroxidation in beef and pork, reduced Fe³⁺ to Fe²⁺ and scavenged DPPH radical. Reducing power of extracts was significantly different (p < 0.05) only at higher concentrations of 20mg/ml. Spice extracts scavenged DPPH in dose dependent order. The antioxidant activity was higher in beef than in pork. Antioxidant capacity increased with increasing spice concentrations and with higher total phenol contents.

Keywords: Phenolic contents, antioxidant activity, Monodora tenuifolia