**4. Conclusions**

The results of this work demonstrate differences of various potato tubers depending on their genotypes and varieties. Mainly Blue Congo tubers and their purple-fleshed cross-breeds were compared to yellow-fleshed potato tubers and purple sweet potato tubers. The levels of total phenolic compounds and anthocyanins found in purple-fleshed tubers were significantly higher compared to yellow-fleshed ones. Although, the Blue Congo and Granola cross-breed showed highest levels of sugars, the PCA analysis showed that additional beneficial anthocyanin concentration was in correlation with higher sugar content. In addition, the results confirmed that cross-breeding Blue Congo with a yellow-fleshed tuber does not diminish the positive benefits of high levels of phenolic compounds and anthocyanins.

The results showed great potential to create versatile plant material with increased levels of specific TPs or anthocyanins, as well as adding to the knowledge of correlations of micronutrients to TPs, sugars, and anthocyanin concentrations. Thus, providing health benefits for various consumers to help with essential microelements as well as overall improvement of immune system and health.

**Author Contributions:** Conceptualization, M.V. and V.R.; field tests, K.K.; analysis, M.V., P.S.-R., M.K. (Maria Kulp) and M.K. (Maria Kuhtinskaja); writing—original draft preparation, P.S.-R.; writing—review and editing, M.V., K.K. and P.S.-R.; project administration, M.V.; funding acquisition, M.V. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the Estonian Ministry of Education and Research (Grant No. IUT 3320) and SA Archimedes (Development of additional analytical capabilities for Estonian Center of Analytical Chemistry, AKKI).

**Conflicts of Interest:** The authors declare no conflict of interest.
