Stabilization of Groundnut Oil with Natural Antioxidants Extracted from Bauhinia Species and Piliostigma reticulatum

Abstract

The total phenol and antioxidant activity of the crude extract, dichloromethane, ethylacetate and butanol fractions of the leaves of Bauhinia species and Piliostigma reticulatum plants were determined and EC50 value calculated. The extract with highest antioxidant activity was used in the stabilization study of freshly extracted groundnut oil samples. The results revealed that ethylacetate fraction of P. reticulatum had the highest total phenolic content (106.50 ± 2.26 mg gallic acid equivalent per gram extract) and the lowest EC50 value (8.29 μg/mL). The stabilization study revealed that the plant extract-protected groundnut oil recorded the least values for lipid hydroperoxide, thiobarbituric acid reactive substances and p-anisidine value and the least reduction in total tocopherol. This showed that the plant extract had sparring role on tocopherol. It can be concluded that ethylacetate fraction of P. reticulatum was a better antioxidant than butylated hydroxyanisole and could be used as an antioxidant in vegetable oil. Practical Applications The etiology of some diseases such as cancer has been linked to synthetic antioxidant used in the preservation of vegetable oil. Hence, the replacement of these synthetic compounds with extracts obtained from medicinal plants such as Bauhinia species and P. reticulatum will be a step in the right direction. The ethylacetate extract from P. reticulatum showed a great potential as an antioxidant against lipid oxidation. The extract of this plant can be used as a possible replacement for synthetic antioxidants for the preservation of the nutritional quality of vegetable oil.