FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of pre-drying temperature on content of glycoalcaloids and nitrates(V) during laboratory production of dehydrated cooked potatoes


The objective of this research study was to determine the effect of different pre-drying temperatures, applied during the laboratory production of dehydrated cooked potatoes, on the content of glycoalkaloids (α-chaconine and α-solanine) and nitrates(V) in the samples taken from individual phases of the technological experiment. The research material included potatoes taken directly in the production plant’s storage facility. Dried potatoes were produced using a laboratory method. Potato samples for assays in the laboratory were taken from every individual production phase, i.e.: unpeeled potatoes and potatoes after peeling, blanching, and cooling, as well as after steaming and drying. Except for the dried potatoes, the potato samples were lyophilized with the use of a liophilizator made by an Edwards Company. The content of dry matter was determined in the potatoes, semi-finished products, ready-to-eat products, and lyophilized products using a drying method at a temperature of 102 ºC. The content of nitrates(V) in the ready and lyophilized products was determined using a colorimetric method, and the content of α-solanine and α-chaconine therein by a liquid chromatography method (HPLC). It was found that the process of laboratory production of dehydrated cooked potato impacted the content of glycoalkaloids and nitrates(V) in the potatoes. After the peeling, blanching, and drying processes, the decrease in the content of glycoalkaloids and nitrates (V) was the highest. After the manual peeling process, the decrease in the content of glycoalkaloids was 49 %, after blanching: 7 %, and after drying: 10 %. However, the content of nitrates(V) after blanching decreased by 28 %, after blanching by 16 %, and after drying by 17 %. The pre-drying of the potatoes at different temperatures impacted the changes in the content of glycoalkaloids in the samples. The highest decrease in the content of those compounds took place at a temperature of 160 ºC. The differences as regards the content of α-chaconine were 19 % (between the product dried at a temperature of 130 ºC and 160 ºC), and as regards the content of α-solanine, those differences amounted to 23 %; yet, the temperatures did not impact the content of nitrates(V). In the ready-to-eat products, the content of α-chaconine remaining after the processes performed was ca. 22 % of its initial content, the content of α-solanine was 25 %, and of nitrates(V) was 28 %.


glycoalkloids, nitrates(V), dehydrated cooked potatoes