Studies On Marula Oil And Bioactivities Of Sclerocarya Birrea Kernel Oil Meal

Sclerocarya birrea (A. Rich) Hochst. subsp. caffra (Sond.) Kokwaro [English name is marula] is a perennial tree in the family Anacardiaceae which accurs naturally in low altitude area of Southern Africa. Marula fruits were eaten fresh or made into jam, juice and alcoholic beverages. It is also a traditional medicinal tree, the extract of bark, leaf and root of marula had anti-inflammatory, anti-bacterical, anti-spasm, anti-coagulation, hypertension and hyperglycemia. Marula oil is extracted from the S.birrea seed kernels. It is one of the main edible oil of inhabitants in Southern Africa. Marula oil was used in treat leather, skin care or as an additive to meals. In this article, we systematically investigated fatty acids, physicochemical properties and nutrient contents between marula oil and six vegetable oils, and the chemical constitnents and anti-oxidant activities of extracts from S.birrea seed residues after extracting of the oils. Main findings are as follows:According to compared physicochemical properties, fatty acid compositions and nutrient contents between marula oil and six vegetable oils. The results showed that the yield of marula oil was 51.93%. Marula oil consisted of six fatty acids, including oleic acid (76.94%), linoleic acid (9.28%), Palmitic acid and stearic acid (about 6%), Arachidic acid and linolenic acid (less than 1%). Oleic acid, a co-9 monounsaturated fatty acid, was the principal fatty acid in marula oil and olive oil (67.39%), but all the oleic acid contents of other vegetable oils less than 30%. Iodine value (I) of marula oil is 64.2±0.11 g/100g, this showed marula oil with high unsaturated fatty acid. The contents of squalene and ?-sitosterol were 2.5mg/100g and 183.5mg/100g, respectively.Marula seed residues after oil extraction were defatted by petroleum ether, extracted by 60% methanol successively. Total polyphenols were 138.15 mgGAE/g. Antioxidant experiments indicated that 60% methanol extracts from the marula seed residues possessed DPPH and ABTS free radicals scavenging activities with a dose-dependent manner. For the two kinds of free radicals, IC50 were 0.111 mg/mL and 0.102mg/mL. It is clear that marula kernel oil cake had good potential as a natural antioxidant.