Storage Study of Encapsulated Peanut oil: Assessing Shelf Life and Oxidative Resistance

Peanut (Arachis hypogaea L.) is known world-wide for its edible oil. Peanut oil imparts instinct nutty flavour and nutritional value to the foods. The great challenge in the storage of peanut oil arise due to higher susceptibility to the oxidative deterioration. Encapsulation, a technique to enhance the stability of peanut oil was attempted to assess the shelf life and oxidative resistance. Peanut oil was encapsulated using corn starch and whey protein isolate with the help of microwave technique. The encapsulated peanut oil was stored in glass bottles at an ambient conditions for the 180 days. The peanut oil without encapsulation was also stored at similar conditions to assess the effect of encapsulation. The bio-chemical characteristics; peroxide value, free fatty acids, antioxidant activity, and total phenol content, were examined at an interval of 15 days. The results showed that the peroxide value, an indicator of oxidative deterioration, increased during storage. However, the peroxide value was higher for the peanut oil (16.823 meq/kg) without encapsulation as compared to the encapsulated peanut oil (8.040 meq/kg). Also, the rate of free fatty acids (FFA) increase was higher in the peanut oil without encapsulation. The encapsulated peanut oil exhibited a lower change in antioxidant activity (14.04%) compared to the peanut oil (43.33%). The peanut oil showed a higher rate of decrease in total phenol content. Overall, the encapsulation technique proved effective in protecting the peanut oil against oxidative deterioration and thereby increasing the shelf life.