PHYSICOCHEMICAL AND ELEMENTAL ASSESSMENT OF VEGETABLE OILS IN YENAGOA METROPOLIS, BAYELSA STATE, NIGERIA

Azibanasamesa D. C. Owaba*, Samuel J. Bunu and Javier T. Oparaodu

ABSTRACT

Background: Vegetable oils are very imperative component of several industrially manufactured products. They are utilized as lubricants, plasticizers, emulsifiers, surfactants, solvents, plastics, and resins, as well as in animal feed. The waste of vegetable oils has been refined to biodiesel that can be used as normal diesel fuel. Vegetable oils are edible and vital constituent of the human diet, serving as a good source of lipid, protein and fatty acids. Objective: The study aimed to determine some physicochemical parameters and elemental assessment of various brands of vegetable oils in markets within Yenagoa metropolis, Bayelsa State, Nigeria. Method: Ten samples of refined vegetable oils were obtained from different markets. They were tagged as samples A, C, D, G, H, I, J; from Opolo market, while samples B and E were obtained from Kpansia market and sample F was obtained from Market square shopping complex, Opolo, all in Yenagoa, Bayelsa State. The physicochemical analysis was determined using standard methods while elemental assessment was carried out using atomic absorption spectrophotometer. Result: The acidic content of the samples ranges from 0.7-26, revealing that majority of the oils must have undergone hydrolysis as they exceed the acid values of the reference standard of Arachis oil 0.5-0.8. Iodine values range from 3.14-7.04g I2 /100g, while peroxides values range from 2- 33 meq/kg. Also, the saponification values of the samples range from 7.01-183.03 mg/KOH. Heavy metals could be major contaminants in vegetable oils; mercury, lead, chromium, arsenic, cadmium, and selenium were examined and the results showed that the elements are within the acceptable limit as stated by the official standard. Conclusion: There was variation in the physicochemical properties of oils sold. The elemental assessment of the oils analyzed showed all samples were within acceptable standard limits; hence, are safe for human consumption.

Keywords: Vegetable oil, heavy metals, physicochemical, Yenagoa, Spectrophotometry.