Composition and quantification of antocians in healthy-diet potato (Solanum tuberosum L.) varieties for growing and selection in the Russian Far East

The potato ( Solanum tuberosum L.) has been the focus of dietary research in recent decades due to its ability to accumulate phenolic substances (anthocyanins) in tubers. In Russia, such varieties have been created for a number of regions, but in the Far East, the program to increase the content of anthocyanins in potato tubers has recently begun. In the presented study using liquid chromatography and second-order mass spectrometry methods, we profiled anthocyanins and quantified their accumulation for potato varieties of different origin (Russia, Ukraine, Belarus, Kazakhstan, Germany, the Netherlands), which had not previously been characterized by this feature. For the first time, four dietary Russian varieties with an increased content of anthocyanins have been identified. This work aimed to determine the profiles of anthocyanins and their content in tubers in the conditions of the Russian Far East. We used 22 varieties selected for early maturity, productivity, low starch content and different color of tubers and flowers. The anthocyanin profile was double-identified, by the retention time on a C18 reverse phase column with detection of absorbance at wavelength range 400-700 nm and ESI-MS/MS in positive ionization mode. Anthocyanins were quantified spectrophotometrically. The anthocyanins identified in the tubers were delphinidin, petunidin, malvidin, cyanidin, and pelargonidin. Delphinidin and cyanidin were found in mono- and diglycosylated forms. It was revealed that petunidin-3-glucoside is the most common anthocyanin which is present in almost all of the studied varieties. In tubers, depending on varietal specificity, there were from 1 to 5 anthocyanins of those found. Varieties with yellow skin and pink spots on the yellow tuber skin were characterized by a low content of anthocyanins. The pink and dark pink color of the skin positively correlates with the content of pelargonidin-3-glucoside, while petunidin-3-glucoside and cyanidin-3-glucoside give a purple and blue-violet color to the skin of the tuber. The anthocyanin level was the highest in Phioletovii variety (310 mg/kg cyanidin-3-glucoside, 50 mg/kg malvidin, 30 mg/kg delphinidin), Vasilyok variety (150 mg/kg petunidin), and in Mayak (95 mg/kg pelargonidin) and Kuznechanka (78 mg/kg pelargonidin) varieties. In the Phioletovii variety, the cyanidin-3-glucoside prevailed. We recommend to involve varieties with pink, dark pink, purple and blue-purple tuber skin in selection for an increased content of anthocyanins.