Relation of potato compsition to potato size and blackening tendency

A compositional study was conducted on six potato samples representing various degrees of stem-end blackening. The aim of the study was to determine compositional variation with potato size. The compositional characteristics, of stem-and bud-end tissue of various potato sizes, of the six samples were determined. The larger the potato the greater was the tendency for the stem-end to have the following characteristics: (i) low citric acid content, (ii) high K/citric acid, and (iii) relatively low citric acid/polyphenolic content. It was also shown that differences in stem-end blackening tendency between potato samples, as well as differences in blackening within the same sample could be correlated with these same compositional characteristics.