Impacts of Protease Treatment on the Contents of Tocopherols and B Vitamins in Peanuts

This study investigated the changes of tocopherols and B vitamins in raw peanuts as a result of protease treatment which was used to reduce peanut allergens. Raw peanut kernels were treated with Alcalase, bromelain, Neutrase and papain separately at different concentrations, vacuum dried, and then ground into paste. The paste was defatted using hexane containing 0.02% BHT to obtained crude oil and defatted peanut flour which were used for tocopherol and B-vitamin analysis, respectively. The protease treatment significantly reduced the contents of all tocopherols and B-vitamins in the peanuts in enzyme concentration-dependent manner (P<0.0001). The highest losses of α-, γ-, and δ-tocopherols were 60.87 %, 40.60 % and 36.89 %, respectively, while the maximum losses of vitamins B1, B2, B3 and B6 were 63.29 %, 44.83 %, 40.56 % and 49.59 %, respectively. Among tocopherols, α-tocopherol was the most affected while δ-tocopherol was the least affected. Among B-vitamins, B1 was the most affected and B3 the least affected. This study demonstrated that although the protease treatment approach (including enzyme treatment and drying) for peanut allergen reduction resulted in different degrees of losses in tocopherols and B vitamins in raw peanuts, the enzyme treated peanuts is still a good source of tocopherols and vitamin B3 comparing to most cooked legumes and vegetable.