Coloured-fleshed potatoes after boiling: Promising sources of known antioxidant compounds

- Boiled potatoes are a good source of acylated anthocyanins and phenolic acids.
- Total phenols and anthocyanins are correlated to the antioxidant capacity.
- Pink and purple potato pulp can increase the intake of antioxidants in the diet.

This study aims at evaluating the effect of boiling on the anthocyanin and phenolic acid content of varieties of yellow, pink and violet flesh colored potatoes grown in central Italy. The total phenolic acid content ranged from 33.4 to 1130 mg/kg of fresh weight (FW) in uncooked tubers and from 111 to 1375 mg/kg FW in cooked potatoes, with increments obtained for six varieties (Mz012, Mz064, Vitelotte Noir, Mz032, Mz080, Mz046) after boiling. The anthocyanin content decreased in a variety-dependent mode, but an increment was evidenced after cooking in one sample Mz012. A strong correlation was observed between antioxidant capacity and total anthocyanins for pink and violet-fleshed potatoes, suggesting that these compounds are mostly responsible of the antioxidant capacity of these tubers after boiling. Overall, the yellow-fleshed cultivars have shown lower antioxidant capacity (about 3.25 times lower) than the violet-fleshed tubers. Violet Mz064 variety registered the highest anthocyanin level and a daily intake of 100 g of this tuber contains up to 200 mg of total phenols. Flesh-colored potatoes can represent an additional source of bioactive compounds, particularly of acylated anthocyanins in the human diet.