Degradation of Curcubita pepo Seeds Oil by Aspergillus niger

Abstract

Vegetable oil was extracted from Curcubita pepo seeds in n-hexane using Soxhlet extractor at 60°C. The physico-chemical parameters of the purified oil was analysed according to American Oil Chemist Society method. The physico-chemical of oil gave the free fatty acids of 0.83 mgKOH/g, Iodine Value of 97.96 I2 /100 g, viscosity of 4.13 µ, refractive index of 1.46, density of 0.91 g/cm3 and 1.4 mgKOH/g, 50.34 I2 /100 g, 3.17 µ, 0.92, 0.602 g/cm3 for un-degraded and degraded oil respectively. The Fourier Transform Infra Red and Gas Chromatography -Mass Spectroscopy of the oil were determined before and after four weeks of inoculation and incubation with the microorganisms. It was observed that Aspergillus niger partly degrade the oil in four weeks of incubation. The decrease in viscosity of oil as the time of incubation increases was observed. The appearance of absorption peaks corresponding to hydroxyl, carbonyl, and carboxylic functional groups in the spectrogram suggested the formation of compounds such as alcohols, carboxylic acids, esters and nitrates as biodegradation metabolites. Mass Spectroscopy provided the mass fragments of the possible components formed during the degradation of the oil to include: heptadecanioc acid, octadecanoic acid and oleic acids. The formation of three fatty acids was viewed to be due the oil high stability to this fungal attack thereby alluding to thesubstantial application of the Curcubita pepo seeds oil in areas such as soap and detergent as well as usage cooking and or lubricants.