Full Length Research Paper

Extraction performances of polar and non-polar solvents on the physical and chemical indices of African breadfruit (Treculia africana) seed oil

Titus Ugochukwu Nwabueze^*  and  Kalu Sunday Okocha

¹Department of Food Science and Technology, Michael Okpara University of Agriculture, Umudike, P.M.B 7267 Umuahia, Abia State, Nigeria.

*Corresponding author: E-mail: teeubueze@yahoo.co.uk.

Accepted   30   August,  2008

   Abstract

The physical and chemical indices of African breadfruit (Treculia Africana) seed oil extracted with polar (isopropanol, Hexane and butanol) and non polar (Acetone) solvents were investigated. The oil (19.85%) and energy contents 452.35 (Kcal) suggest that African breadfruit seeds are a high-energy food. The yields were significantly (P ≤ 0.05) different with hexane extracted (non-polar solvent) oil having 19.85% whilst oil extracted with polar solvents ranged from 15.58 -19.30%. Melting points were 34, 27, 26, 21 ^ͦC for oil extracted with hexane, isopropanol, butanol and acetone respectively. Smoke points were within the limits of 170 – 255  ^ͦC for the four oil samples. Iodine values ranged from 14.50 (hexane extracted) t0 25.17 (acetone extracted). Saponification values ranged from 125.89-267.85 while peroxide values were 3.20 mg/kg (hexane) and 3.60-3.83 mg/kg for polar solvents. Free fatty (oleic) acid of oil extracted with hexane was 1.71% and polar solvent extraction ranged from 1.65-1.78%. Hexane had the least peroxide value (8.74 mg/kg) compared to higher values for oil extracted with the polar solvents (9.10 - 9.83 mg/kg).

Keywords: African breadfruit, Treculia Africana, oil extraction, saponification, fatty acids, peroxide value, thiobarbituric acid.