Preliminary nutritional evaluation of cashew nuts from different locations in Nigeria

Abstract

Cashew nut samples from three geographical locations of Nigeria viz: Anambra state, Oyo state and Kogi state were obtained and analysis were carried out on the nuts and oil. The proximate composition of the cashew nuts was determined. The extracted oil was analyzed for both physical (colour, specific gravity and refractive index) and chemical (saponification value, iodine value, peroxide value and free fatty acid value) properties. The vitamin content of the samples was also determined. The protein content ranged from 23.42% – 26.39%, the moisture content ranged from 5.66% - 6.17%, ash content ranged from 3.03% - 3.18% and the crude fibre content ranged from 5.60% - 6.12%. The fat content of the cashew nut from Oyo state was the highest (42.03%) followed by the cashew nut from Kogi state (40.72%) while the cashew nut from Anambra state had the least value (40.15%). The refractive index ranged from 1.452 – 1.463nD 20ºC and specific gravity ranged from 0.848 – 0.860g/cm3. The oil from the three samples had a light yellow colour. The saponification value ranged from 233.19 – 237.00mgKOH/g oil; iodine value 83.65 – 86.93mgKI/100g oil; peroxide value 19.75 – 20.34meqO2/Kg oil and free fatty acid 0.05046 – 0.05601%. The mineral content of the samples correlated with the values from literature. Statistical analysis was carried out using the Analysis of Variance (ANOVA) at 95% confidence limit and Duncan test. There was significant difference between the Vitamin A and B12 content, Sodium, Potassium, Magnesium, Phosphorus, moisture, fat, fibre, ash, carbohydrate and free fatty acid content of the samples while there was no significant difference in the Vitamin B12 and B6, Iron, Zinc, Iodine value and Saponification value of the samples. The cashew nuts from the different locations demonstrated high potential as industrial materials.