3.6. Varietal differences in polyphenol content of potato chips
Total phenolic content in potato chips was also lower in comparison with raw material, yet losses of those compounds varied considerably (Table 3). Among potato chips obtained from purple varieties, the biggest losses were observed for samples made of Blaue St. Galler (64%), while for Vitelotte there were no losses at all. That phenomenon was also observed for two red fleshed varieties – Highland Burgundy Red and Herbie 26. The losses for other two varieties didn't exceed 16%. Such diversification in polyphenols stability in fried potato (as potato chips) could be explained by significant diversity of phenolic compounds present in potatoes. Thermal treatment like frying caused not only degradation but also transformation of different groups of polyphenols (Bąkowska, Kucharska, & Oszmiański, 2003). On the other hand, potato chips are almost dehydrated products so concentration of substances typical for dry matter of potato tubers increases in ready product.