Fatty acid profiles, antioxidant, and phenolic contents of oils extracted from <i>Acacia polyacantha</i> and <i>Azadirachta indica</i> (Neem) seeds using green solvents

Abstract

The purpose of the present study was to evaluate the composition of fatty acids, antioxidant, and phenolic compounds in Acacia polyacantha and Azadirachta indica seed extracts for their potential uses in nutrition. Extractions of oil using several techniques (Soxhlet, ultrasound, and microwave) in several solvents were carried out and the oils were characterized. Total phenolic content ranged between 4.22 and 31.48 mg GAE/g. Antioxidant activity (CE50) ranged between 1.95 and 22.91 mg/ml. Oleic and linoleic acids were the major unsaturated fatty acids while palmitic and stearic acids were the major saturated fatty acids in both oils. 3-hydroxybenzoic acid, resveratrol rutin, and flavan were identified by HPLC-DAD at high contents while chlorogenic acid, vanillic acid, syringic acid, epicatechin, p-coumaric acid, transferulic acid, ellagic acid, rutin, cinnamic acid, chlorogenic acid, and caffeic acid were lower in Neem oil. In case of A. polyacantha oil, the percentages of ellagic acid and rutin were high. Practical applications This study investigated the best method which gives a high oil extraction yield from among Soxhlet, ultrasound, and microwave using green solvents. Results revealed that acetone and isopropanol can be used for oil extraction from seeds using microwave or ultrasound with shorter extraction times (30 min with ultrasound and 15 min for microwave). These solvents provided oils with high phenolic content and good antioxidant properties. The main fatty acids identified were oleic, linoleic, palmitic, and stearic acids. These oils thus have a high potential for pharmaceutical, food, and cosmetic industrial uses.