Tannin impregnation pre-treatment of potatoes as a valuable strategy for acrylamide, monochloropropanediol and glycidol mitigation in chips and frying oil

This study focused on evaluating the mitigating effect of five different natural extracts of commercial tannins on the concentration of food contaminants such as acrylamide (AA), glycidols (GD), and monochloropropanediols (MCPDs) in potato chips and frying oils after the impregnation of potatoes with tannins. The impregnated samples were used to perform 4 consecutive fryings to simulate the effect produced in restaurants. AA mitigation was achieved in all pre-treated chips throughout the four frying cycles (except for the chestnut extract). The highest AA mitigation (86.6%) was achieved using quebracho extract. This correlated positively with the progress of Maillard reaction measured at 284 nm. In potato chips, 3-MCPD and GD were decreased by most tannins tested, whereas 2-MCPD was only mitigated using hydrolyzable tannins. However, in frying oils, 3-MCPD showed a decrease using chestnut, grape seed and quebracho extracts, 2-MCPD decreased using all tannins, and no effect was observed on GD. To our knowledge, this is the first study using tannins as a mitigation strategy to decrease MCPDs and GD; and it seems a good approach to keep low concentrations of these compounds. Indeed, hydrolyzable tannins seem the best option to mitigate MCPD and GD and condensed tannins the best one to mitigate AA.