Variation in diosgenin level in seed kernels among different provenances of Balanites aegyptiaca Del (Zygophyllaceae) and its correlation with oil content

Abstract

Balanites aegyptiaca (Zygopyllaceae) is a widely grown desert plant with multi-use potential. It is found in most of the African continent, the Middle East, and South Asia; however, this plant remains one of the most neglected plant species. Its seed kernel is used for oil extraction and the oil is used for human consumption and cosmetics. However, the oil cake is regarded as unsuitable for feeding because of the presence of many toxic substances. In this study, a spectrophotometric determination of diosgenin level and subsequent oil percentage analyses were carried out using the seed kernels of B. aegyptiaca collected from five Israeli provenances (Bet-Shean, Ein-gedi, Sapir, Samar, and Eilat) and five international locations (Burkina Faso, Senegal, Mali, Niger, and India). The results suggested that the sample from the Bet Shean Valley, which is considered the northern-most latitude where B. aegyptiaca naturally grows, contained the highest level of diosgenin as well as oil percentage; the Indian sample contained the lowest levels of both diosgenin and oil. The result also showed that there is a strong positive correlation (R2 = 0.849) between diosgenin level and oil percentage in the B. aegyptiaca seed kernel.