Effects of tea polyphenols and tertiary butylhydroquinone on quality of palm oils and losses of endogenous vitamin E during batch frying and oxidative stability of fried instant noodles.

The effects of tea polyphenols (TP) on the quality of palm oils (PO) and losses of endogenous vitamin E during batch frying of instant noodles as well as oxidative stability of fried instant noodles were investigated. PO without antioxidant addition was negative control and with tertiary butylhydroquinone (TBHQ) addition positive control. TP and TBHQ addition inhibited the increase of peroxide, -anisidine, and total oxidation values of PO and reduced tocopherol and tocotrienol losses with 200 mg/kg of TP having the best performance, but didn't affect acid value and triglyceride composition. 200 mg/kg of TP and 100 mg/kg of TBHQ inhibited unsaturated fatty acid losses. During frying, TBHQ was mainly volatilized but TP transformed. TP more effectively reduced tocopherol and tocotrienol losses than TBHQ, reducing PO deterioration. The extended lifecycles of PO and shelf life of fried instant noodles are attributed to nonvolatility of TP and antioxidative properties of its transformation products.