PHYSICOCHEMICAL PROPERTIES, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF PAPAYA (Carica papaya L.) SEED, RIND AND PULP OILS

Abstract

Carica papaya (L.) is a monoecious, dioecious or hermaphrodite tree; it belongs to the family Caricaceae. It is widely cultivated throughout the world and is used as food and traditional medicine, particularly as an antiseptic and contraceptive. Papaya contains many biologically active compounds. Fruits, leaves, latex and stems are used to treat indigestion, diarrhoea, stoppage of urination, blindness and alopecia. The aim of this work was to assess the physicochemical properties, antioxidant and antimicrobial activities of oils extracted from (C. papaya L.) seeds, pulp and rind using solvent extraction method. The results of the physicochemical properties of C. papaya (L) seeds, pulp and rind oil extracts demonstrated significantly high oil yield (42.50%) and specific gravity (0.85) which were obtained for seed oils. The highest acid value (2.10) and free fatty acid (1.06) were, however, obtained from rind oil and significantly higher peroxide value (1.80) was obtained for pulp oil than for oil extracts of the other tested parts. Significant differences in antioxidant activity parameters: DPPH radical scavenging activity, hydrogen peroxide scavenging activity, ascorbic acid (AA) were observed for the oil extracts. Significantly higher DPPH RSA (19.35±0.14), and HPSA % (32.45±0.07) were recorded for seed oil extract. The strongest antibacterial activity with maximum zone of inhibition (18.50mm) at highest dose (3μl/ml) was recorded for seed oil extract against S. pyogenes. Thus, seed oil has exhibited more antibacterial potential than pulp and rind oil extracts in C. papaya (L). In contrast, the strongest antifungal activity with maximum zone of inhibition (16.75mm) was recorded for rind oil extract against C. albicans suggesting rind oil extract was the most effective antifungal as compared to seed and pulp oils in papaya (C. papaya L.). The seed oil extracts from C. papaya has exhibited the strongest antibacterial activity with minimum inhibitory concentration MIC 0.03μl/ml and MBC 0.05 μl/ml against S.pyogenes while the weakest antibacterial activity with MIC (0.75μl/ml the largest value) and minimum bactericidal concentration (MBC, 1.00μl/ml) was recorded for rind oil against S. typhi indicating that S.pyogenes (gram positive) was more susceptible to the oil extract than s.typhi and also indicating that seed oil extract had the strongest antibacterial activity among the extracts in papaya (C. papaya L). The rind oil extract of C. papaya (L) had shown the strongest antifungal activity with MIC (0.05μl/ml, the least value) and MFC (0.10μl/ml) against C. albicans whereas the weakest antifungal activity with MIC (0.75μl/ml) and MFC (1.25 μl/ml) was observed for the papaya pulp oil extract against A. niger showing that C. albicans was more susceptible to the oil extract than A. niger and the rind oil was the most effective antifungal extract of the three different oils of C.papaya L. tested in this study.