Effect of different oil extraction techniques for Moringa Peregrina seed on its meal content of glucosinolates

Abstract

Background Moringa peregrina (M.P) is a multipurpose promising tree that grows widely in Asia and Africa’s tropical and subtropical regions. It is generally rich in nutrients especially oil which can be used for edible or nonedible purposes and also rich in protein. However, some anti-nutritional substances, namely glucosinolates (GSLs), remain in M.P meal preventing its utilization in animal or human feeding. These substances though good for the plant to defend against herbivores, cause deleterious effects or are even toxic to animals and humans. GSLs are the most important anti-nutritional substances in M.P seed and meal. Objective Accordingly, this investigation aims to use different techniques for oil extraction from M.P seed and their effect on the GSLs content of the meal remaining after oil extraction, then the meal is detoxified to be suitable for using in animal or human feeding. Materials and methods In this study, M.P meal was obtained as a by-product left over after oil extraction from moringa seed by different extraction procedures including (hydraulic press, screw pressing, extraction by solvent via Soxhlet, and prepress − solvent extraction at room temperature).The sinalbin, moringin, and total GSLs were determined and identified by HPLC. Detoxification of GSLs was then applied for M.P meal remaining after oil extraction by hexane, using soaking in water followed by a water-washing treatment. Results and conclusion The results indicated that sinalbin and moringin are the major dominant GSLs in M.P seed and meal. Moreover, the total GSLs content in the meal that remained after all different oil extraction techniques was significantly higher when compared with their content in the seed. Also, the results showed that there was a significant decrease in the level of total GSLs in M.P meal as a result of the water treatment. It decreased from 941.8±34.14 nmol/mg in defatted meal before water treatment to 23.97±18.31 nmol/mg in residues left after treatment with water for 15 min. Therefore, soaking in water followed by a water-washing treatment is the simplest and most efficient process to remove the GSLs from M.P meal to be suitable for animal feeding.