Phenolic compounds from mashua tuber were evaluated as potential antioxidants to retard the oxidation of crude soybean oil submitted to accelerated storage and frying. During the accelerated storage, an ethanolic crude extract, a purified extract, an aqueous fraction and an ethyl acetate fraction from mashua containing different gallic acid equivalent concentrations (100, 300 and 600 ppm) in oil were evaluated at 55 C. After 15 days of storage, better effects were evidenced against soybean oil oxidation at 300 and 600 ppm of ethyl acetate fraction in comparison to 200 ppm butylated hydroxytoluene and the control (no antioxidant added). During the frying process at 180 C, principal component analysis revealed that the content of trienes and dienes were strongly correlated with the frying batch. Ethyl acetate fraction at 200 ppm showed the highest efficacy against oil oxidation in terms of...

We thank Dr. Carlos Arbizu, International Potato Center (Lima, Peru) for providing the mashua genotypes. This research was supported by the CUI project of the Cooperation Universi- taire au Developpement (CUD, Belgium), and by the Consejo Nacional de Ciencia y Tecnolog´ıa (CONCYTEC, Peru).