Effects of Organic Acids on Phenolic Compounds and Antioxidant Activity During the Processing of Potatoes with Colored Flesh.

Potatoes with colored flesh are increasingly processed in the food industry. However, establishing appropriate production parameters is challenging because anthocyanins and other polyphenols present in potatoes undergo structural transformations during processing. Therefore, this study investigated the effects of five organic acids applied during the production of dehydrated potato grits on the content, profile, and stability of phenolic compounds in the final products manufactured from tubers of the red-fleshed potato cultivar Lily Rose (LR) and the purple-fleshed cultivar Double Fun (DF). The effects were assessed by analyzing the profiles, antioxidant activity, and content of the phenolic compounds in the final products. Phenolic compounds were analyzed by high-performance liquid chromatography (HPLC), while antioxidant activity was evaluated using the FRAP, DPPH, and ABTS assays. Only malic acid improved anthocyanin retention in LR potato products, while tartaric and malic acids had the greatest effect on the content of the analyzed compounds in DF potato products. Citric acid showed only a moderate stabilizing effect on anthocyanin content. Grits produced with malic and tartaric acids contained 20-67% more phenolic acids than the control and showed higher antioxidant activity. Lactic acid had an adverse effect, particularly in LR dehydrated potato grits. Depending on the potato cultivar, the effectiveness of organic acids in stabilizing anthocyanins varied. Therefore, the processing conditions for colored potatoes should be optimized for the specific cultivar.