Evaluation of reproducibility methods for total phenolic and flavonoid content in skin and flesh of potato (Solanum tuberosum)

Potato is the most consumed crop in the world has a rich source of phenolic compounds having antioxidant properties beneficial in reducing the risk of many diseases. Spectrophotometric methods, in particular the Folin-Ciocalteu method is used to quantify total phenolic content in food and plant samples but lacks proper standardized procedure. Therefore, this study was conducted during the 2019 at Lorch Potato Research Institute, Moscow region, Russia to estimate the reproducibility of spectrophotometric methods for determining the total phenolic and flavonoid content in 4 varieties of potato with different skin and flesh colors. Potato varieties viz. Udacha, Surpriz, Monakh and Vimpel were used for the study. Results obtained from 3 independent tests of the same sample for each of the varieties indicated the absence of significant differences, except for a variety Udacha. The total content of studied compounds in the skin was higher than in the flesh, with the exception of a variety Vimpel, in which no significant differences were detected. Also, the total phenolic and flavonoid content of pigmented varieties was higher both in the flesh and in the skin. The influence of a degree of flesh grinding of Surpriz variety on the total phenolic content was established. The identified differences in the total phenolic content between the tests of the variety Udacha as well as a decrease in the total phenolic content due to increase in the degree of grinding, may be a consequence of the enzymatic browning reaction. To obtain more accurate results, standardization of the grinding and extraction procedures are necessary. © 2020, Gaurav Society of Agricultural Research Information Centre. All rights reserved.