## 3 Results and Discussion  
### Fat Content and Color  
Crisps from Provita had a higher fat content than crisps from Ismena (Table 2). Furthermore, the use of blanching resulted in an increase in the fat content of the crisps. Among all variants of thermal treatment, the crisps blanched at 85 \({}^{\circ}\)C for 4 min and fried in oil at 175 \({}^{\circ}\)C were characterized by the highest fat content (43.56%) when the Ismena cultivar was used as the raw material. The lowest fat content (37.39%) was found for crisps blanched and fried at the same temperatures, when the blanching time was 1 min. In the case of the _cv._ Provita, the highest fat content was seen for crisps blanched at 85 \({}^{\circ}\)C for 2.5 min and fried at 155 \({}^{\circ}\)C (52.20%), and the lowest was found for those with no blanching and fried at 175 \({}^{\circ}\)C (38.57%). Extending the blanching time increased the fat content of potato crisps. The effect of the blanching temperature was ambiguous--in the crisps of the _cv._ Ismena, the fat content increased with the rise of the blanching temperature, while the opposite relationship was observed in the crisps of the _cv._ Provita. The frying temperature also influenced the fat content of the potato crisps. As the frying temperature increased, the crisps absorbed less fat. The results of the instrumental measurement of the color of potato crisps from potatoes with different flesh color, obtained with the use of different thermal treatment parameters, are presented in Tables 3 and 4. The color was determined using the parameters \(L^{*}\), \(a^{*}\), and \(b^{*}\), which define the brightness (\(L^{*}\)), as well as the share of red and green (\(a^{*}\)) and yellow and blue (\(b^{*}\)). The color saturation (\(C^{*}\)) and hue (\(h^{\circ}\)) were also determined. Among the crisps of the _cv_. Ismena variety with the yellow flesh color, the darkest color was that of the unblanched crisps fried at 175 \({}^{\circ}\)C (\(L^{*}\) = 55.36), and the lightest were crisps blanched at 85 \({}^{\circ}\)C for 2.5 min and fried at 155 \({}^{\circ}\)C (\(L^{*}\) = 62.76). Purple flesh potato crisps were the darkest for the sample blanched at 85 \({}^{\circ}\)C for 2.5 min and fried at 175 \({}^{\circ}\)C (\(L^{*}\) = 37.28), and the brightest for the unblanched sample, fried at 155 \({}^{\circ}\)C (\(L^{*}\) = 40.73). Increasing the temperature and lengthening the blanching time lightened the color of the crisps of _cv_. Ismena and darkened the color of the potato crisps with the purple flesh color. On the other hand, the increase in the frying temperature affected the darkening of the crisps (both yellow and purple). The value of the \(a^{*}\) parameter in the crisps of _cv_. Ismena ranged from 2.05 (blanching at 85 \({}^{\circ}\)C/2.5 min; frying at 155 \({}^{\circ}\)C) to 8.83 (variant without blanching; frying at 175 \({}^{\circ}\)C). The use of the blanching process reduced the share of red color (parameter \(a^{*}\)) in potato crisps of yellow flesh. In potato crisps with purple flesh, the relationship was opposite--blanching the crisps increased the share of red color in the finished product. The highest red color share was recorded for blanching crisps at 80 \({}^{\circ}\)C for 2.5 min and frying at 175 \({}^{\circ}\)C (\(a^{*}\) = 1.99), and the lowest for unblanched crisps fried at 175 \({}^{\circ}\)C (\(a^{*}\) = 0.93). Extending the time and increasing the blanching temperature resulted in a decrease in the share of red in the finished product. On the other hand, increasing the frying temperature increased the proportion of red in the crisps from yellow flesh potatoes. Frying had no effect on the changes of this parameter in potato crisps of _cv_. Provita. The \(b^{*}\) parameter values were positive for the crisps of _cv_. Ismena, which is related to the yellow color of the potato flesh.