Fats, Oils and Oil Fruits Processing Evaluation of the Physico-Chemical Characteristics and Oxidative/Hydrolytic Stabilities of Oils of African Pear (Dacryodes edulis) and Bullet Pear (Canarium schweinfurthi) Fruits
Duru, F. C.; Ochulor, D. O. & Uneanya, G. C.
Department of Food Technology
Federal Polytechnic Nekede, Owerri, Imo –State, Nigeria
E-mail: durufaustina@gmail.com
ABSTRACT
The physic-chemical characteristics and Oxidative/Hydrolytic stabilities of oils of African pear and Bullet peat fruits were studied. African pear fruit (APF) and Bullet pear fruit (BPF) oils were greenish yellow in colour. The saponification, unsaponifiable matter and specific gravity values of APF oil were greater than those of BPF oil. APF oil has more saturated fatty acids as its iodine value (49.40mg/100g) was smaller than that of BPF oil (75.12mg/100g). The exposure of the oils to atmospheric condition for nine weeks changed the free fatty acid values of APF and BPF oils, respectively from 0.06 and 0.09mg/g in the first week to 5.87 and 4.06mg/g in the ninth week. At the same period of exposure to atmospheric condition, the APF oil showed faster rate of deterioration than BPF oil as the peroxide values were found to change from 0.60 – 18.50mg/kg for APF oil and 0.20 – 12.50mg/kg for BPF oil. The oxidative/hycholytic changes at accelerated condition (at the condition where the oils were heated at one hour intervals for total period of five hours) showed that the peroxide values changes from 0.90 – 7.10mg/kg for APF oil and 1.00 – 9.30mg/kg for BPF oil.
Keywords: African pear fruit oil, Bullet pear fruit oil, physico-chemical characteristics
