PHYSICOCHEMICAL PROPERTIES OF SOME COMMERCIAL GROUNDNUT OIL PRODUCTS SOLD IN SOKOTO METROPOLIS, NORTHWEST NIGERIA

¹Musa M. ¹Sulaiman, A. U ²Bello; I. ³Itumoh J. E. ⁴Bello K .; ¹Bello A. M.; ¹Arzika, A. T.

¹Department of Chemistry, Shehu Shagari Collage of Education, Sokoto

²Department of Biochemistry, Usmanu Danfodiyo University,

³Department of Industrial Chemistry, Ebonyi  State University Abakaliki

⁴Department of Natural Sciences, Sokoto State Polytechnic, Sokoto

E-mail:oshiobugie2007@yahoo.com

ABSTRACT

Groundnut oil, also known as peanut oil or just vegetable oil is widely used in all homes in Nigeria in cooking and in other kitchen processes. The Northern part of Nigeria is also notable for the production of groundnut seed (Arachis hypogea L.) which is one of the major sources of groundnut oil in Nigeria. The physicochemical properties of commercial groundnut oils sold in Sokoto metropolis, Sokoto State, Northwest Nigeria were investigated in this study. Four different groundnut oil products purchased from Sokoto main market, Old market, Kara market and Mabera area within the metropolis and one extracted from groundnut seeds in our laboratory were analysed. The oil from Mabera has the highest saponification value of 215.05 ± 1.36 mg KOH/g which is significantly high compared to that extracted in our laboratory (175.78 ± 0.93). Iodine value was significantly higher at (p˂ 0.05) in oil from our laboratory (95.87 ± 0.15 g/100 g) compared to oils from Sokoto main market (43.72 ± 0.21) and Mabera area (45.12 ± 0.35). Groundnut oil from Sokoto main market has the highest acid value of 6.83 ± 0.15 which was above the cut-off value of 5.99, while the oil extracted in our laboratory has the lowest acid value of 1.88 ± 0.15. There was no significant difference at (p˂ 0.05) in the specific gravity of the different oil samples. The range was 0.900 – 0.918. The results show that the oils are of good nutritional value and are good for industrial applications, hence the oils pose no significant health risks to consumers in Sokoto metropolis.

Keywords: Groundnut oil, Mabera, Sokoto, Physicochemical properties