Discolouration of raw and cooked coloured fleshed potatoes differing in anthocyanins and polyphenols content

• Published in: International journal of food science & technology 2019-01, Vol.54 (1), p.92-101
• Main Authors: Rytel, Elżbieta, Nemś, Agnieszka, Pęksa, Anna, Kita, Agnieszka, Miedzianka, Joanna, Tajner‐Czopek, Agnieszka, Kucharska, Alicja Zofia, Sokół‐Łętowska, Anna, Hamouz, Karel
• Format: Article
• Language: English
• Subjects: Anthocyanins; colour fleshed potatoes; Darkening; Discoloration; discolouration; Polyphenols; Potatoes; raw and cooked potato; Tubers; Vegetables
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.13909

Summary Despite variations in the content of polyphenols, the tested potato varieties with red and purple flesh contained similar amounts of anthocyanins. Potatoes of the red‐fleshed HBr variety were distinguished by a significant content of pelargonidin‐3‐feruloylrutinoside‐5‐glucoside, and those of the purple‐fleshed Vitelotte variety were characterised by a significant cyanidin‐3‐rutinoside content. Immediately after cutting, raw potatoes with red flesh showed a small share of yellow (b* parameter) and double the share of red (a*) as compared to purple‐fleshed tubers. A reduction in the share of red dye was observed in purple‐ and red‐fleshed potatoes except Vitelotte and Rosalinde tubers, at both 1 and 4 h after being cut. The flesh colour of cooked potatoes was characterised by low susceptibility to darkening, and purple‐fleshed tubers were more saturated by chroma than tubers of red‐fleshed varieties. Despite variations in the content of polyphenols, the tested potato varieties with red and purple flesh contained similar amounts of anthocyanins. Potatoes of the red‐fleshed HBr variety were distinguished by a significant content of pelargonidin‐3‐feruloylrutinoside‐5‐glucoside, and those of the purple‐fleshed Vitelotte variety were characterised by a significant cyanidin‐3‐rutinoside content. Immediately after cutting, raw potatoes with red flesh showed a small share of yellow (b* parameter) and double the share of red (a*) as compared to purple‐fleshed tubers. A reduction in the share of red dye was observed in purpleand red‐fleshed potatoes except Vitelotte and Rosalinde tubers, at both 1 and 4 h after being cut. The flesh colour of cooked potatoes was characterised by low susceptibility to darkening, and purple‐fleshed tubers were more saturated by chroma than tubers of red‐fleshed varieties.