A comparative study on proximate and mineral composition of coloured potato peel and flesh

BACKGOUND Potato peels are usually discarded before consumption of the tubers. However, it could be expected that red‐ and purple‐fleshed potato peels contain more minerals. Therefore, the purpose of the study was to evaluate and compare the proximate and mineral composition in flesh and peels of six coloured potato cultivars. Five proximate compositions (dry matter, total soluble solids, protein, fibre, and ash) and nine minerals [phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), zinc (Zn), copper (Cu), Boron (B), manganese (Mn)] content were determined. The data obtained were evaluated employing the multivariate analysis techniques: principal component analysis and hierarchical cluster analysis. RESULTS The results show that proximate and mineral composition depends on potato tissue and cultivar. Potato peels have significantly higher levels of protein, fibre, ash and minerals (except Mg) than the flesh. However, flesh contains the highest contents of dry matter and total soluble solids. Of the studied elements, K has the highest content in both parts of the potato tuber followed by P, Mg, Ca, Fe, Zn, B, Mn, and Cu. Violetta peels had the highest contents of ash, K and Mg, and Highland Burgundy Red peels had the highest protein, fibre, Ca, Mn contents. The flesh of the Highland Burgundy Red cultivar shows the highest contents of dry matter and total soluble solids. CONCLUSION Based on the present study, it can be concluded that the investigated red and purple potato peels showed significantly higher protein, fibre, ash and element (K, Ca, Mg, P, Fe, Cu, Zn, Mn, B) contents compared to the flesh. © 2019 Society of Chemical Industry