Effect of Vitamin E and Vitamin C on the Antioxidant Activity of Malt Rootlets Extracts

To valorize the malt rootlets, a byproduct usually used as animal feed, two types of antioxidant extracts have been produced. The influence of vitamins C and E on their antioxidant properties has been analysed. An antagonistic effect with ascorbic acid, varying from 6 to 59%, has been found as well with the free and bound antioxidant molecules of the rootlets, while a synergism, from 4 to 56%, has been observed with -tocopherol. The oxidative degradation rate of -tocopherol, followed by HPLC-electrochemical detection, was slowed down by the presence of the malt rootlets extract, due to two possible mechanims: the protection of -tocopherol against oxidation thanks to the action of the rootlets antioxidants as radical chain breakers, or the recycling of -tocopherol from its radical form.