Effect of processing methods on the antioxidant potentials of netlespurge (Jatropha tanjorensis) and black nightshade (Solanum nigrium) vegetables in peanut burger

Abstract

Two lesser known indigenous vegetables: netlespurge (Jatropha tanjorensis) and black nightshade (Solanum nigrium) were each processed into flour samples and were incorporated into wheat flour in coating peanut. These veggie peanut burgers were analysed for their antioxidant properties such as DPPH, FRAP and Metal Chelating ability assay and their linoleic acid inhibition. Veggie peanut burger with netlespurge vegetable had values between 44.62 to 68.32%, 0.0106 to 0.0253 mg AAE/g sample and 49.03 to 63.30% for DPPH, FRAP and Metal chelating assay, respectively, while veggie peanut burger with black nightshade had values between 54.97 to 72.70%, 0.0105 to 0.0173 mg AAE/g sample and 47.13 to 64.01% for DPPH, FRAP and Metal chelating assay respectively. The result of the inhibition of linoleic acid of the peanut burger incorporated with vegetables revealed the abilities of the vegetables to inhibit propagation of peroxides up till the fourth day. Netlespurge vegetable had absorbance values of 2.3220 µm initially rising to 2.6845 µm on the fourth day and a fall absorbance value of 1.1845 µm on the sixth day while Black Nightshade vegetable had absorbance values of 2.3670 µm initially rising to 2.7490 µm on the fourth day and a fall absorbance value of 1.2355 µm on the sixth day. This study concluded that processing methods does not eliminate the antioxidative properties of vegetables and the inclusion of vegetables into peanut burgers increased their antioxidative properties.