Carotenoids and total phenolic content in potatoes with different flesh colour.

Polyphenols are recognized as the most abundant antioxidants in our diet. Potatoes are a good source of these compounds. Phenolic compounds represent a large group of minor chemical constituents in potatoes, which play an important role in determining their organoleptic properties. Further, phenolics have a wide-array of health providing characteristics. The aim of this research was to determine the content of total phenolic and carotenoid (TPC) content in relationship with the colour of organically and conventionally cultivated potato varieties (Solanum tuberosum L.) with different flesh colour. In cooperation with the State Priekuli Plant Breeding Institute (Latvia), sixteen potato genotypes were studied. The highest TPC and carotenoid content was determined in potatoes of Purple Peru variety when conventionally cultivated. Correlation was found between TPC and colour L* (r=-0.813). The changes in carotenoid content and TPC of potatoes vary significantly according to the type of cultivation practise, depending on variety. There are common tendencies in the changes of TPC and carotenoid content – the variety was the most significant factor (p<0.001).