Stability of traditionally processed vegetable oils and their blends under different storage conditions
The objective of the study was to investigate the stability of traditionally processed palm oil (PO), sunflower oil (SO) and sesame oil (SSO) and their blends as function of storage conditions by analysing their physicochemical properties which included acid value, saponification value, peroxide value, iodine value and refractive index. The oils and their blends were stored in two different conditions; one batch at the air-tight dark conditions, while another batch at the air free-ambient, both for 60 days. Sampling was done once after 10 days and the analyses conducted using standard methods. Samples stored at the air-tight dark conditions remained relatively stable than those at the air free-ambient temperature, with SSO showing the highest stability under the studied storage conditions. Generally, the blends showed better stability than the unblended, with some few exceptions, formulations having higher proportions of SSO showed desirable qualities based on physicochemical parameters evaluated. Hence, such traditionally processed vegetable oils should be specially packed to keep them free from the light and air for prolonged storage. The study further reveals the significance of blending in improving the quality and stability of vegetable oils.
Keywords: Palm, Sunflower, Sesame oil, Blends, Traditionally processed oils, Storage, Stability.