Antioxidant capacity, oxidative stability and sensory evaluation of peanut oils produced using different processing techniques

Four differently processed peanut oils viz. refined, filtered, cold pressed and organic were selected for the study. The total antioxidant capacity was estimated by DPPH method, Ferric Reducing Antioxidant Power and in vitro digestibility of antioxidants was determined. The oxidative stability of the samples was tested by biodiesel Rancimat analysis. Organoleptic evaluation was done using a 5 point hedonic scale. When analyzed by DPPH method, and FRAP method, filtered peanut oil showed highest antioxidant capacity followed by refined oil. The percent digestibility of antioxidants was highest in case of organic peanut oil (92.3%). The oxidative stability results showed that cold pressed oil was most stable at all temperatures followed by filtered oil. Although, the oil samples showed difference in the sensory scores, the potato chips deep fried in these peanut oils did not show statistically significant difference (P<0.05). Filtered peanut oil had highest antioxidant capacity but the digestibility of antioxidants was higher in case of organic peanut oil. The results need to be validated by in vivo studies. Cold pressed oil was most stable at all temperatures so it is more suitable for deep frying.