The diploma thesis is focused on enzyme hydrolysis of potato protein concentrates and fractionation of obtained peptide fragments. Were used protein concentrate from tubers variety Ornella and protein concentrate obtained by swedish company Lyckeby Starch AB. The enzyme hydrolysis lasted 24 hours and were used the proteolytic enzyme alkalasa and trypsin. In this work were prove possitive effect of enzyme hydrolysis on solubility and antioxidative properties of potato protein isolates. The fractionation of obtained peptide hydrolysated was based on systém FPLC (Fast protein liquid chromatography). The fractions contained of peptide fragments about 1, 350 kDa or fragments of smaller moleculary weight. The antixodative activity of subfractions were determIne by method called DPPH. The highest values (2,2 and 2,6 TEAC g/kg) were accured at the subfractions which were separations from Ornella hydrolyzates digeste by enzyme alkalasa.

Partial hydrolysates of two types potato protein concentrates were produced by four selected food proteases. Commercialy produced (company Lyckeby) protein concentrate and laboratory prepared concentrate from tubers of Ornella cultivar were subjected of enzymatic hydrolysis by Fromase 220TL, Fromase 220XLG, Maxiren XDS (commercialy available forms of chymosin) and Neutral protases from bacterial Bacillus subtilis. Protein profile of hydrolysates was created using SDS-PAGE. All hydrolysates were determined by solubility and antioxidant activity using DPPH method. The main aim of this study was to evaluate the efficiency of digestion potato protein concentrate by these selected proteases. Based on the results, the most effective enzyme used for hydrolysis of PC was Neutral proteases form Bacillus subtilis.

In this study, a Consequential Life Cycle Assessment (CLCA) was conducted on the introduction of a potato protein for human consumption in Sweden. The assessed environmental impact cathegories in the CLCA were the categories global warming potential, eutrophication and land use. Potato protein is a side-stream that occurs during the production of potato starch and is currently used for animal feed (feed-grade). With the use of the new gene-editing technique CRISPR-Cas9, the stability of proteins in a starch potato can be improved to make the potato protein fit for human consumption (food-grade). The food-grade potato protein can be used as an ingredient in the food products: plant-based meat, quiche, sauces, wine and smoothies. When using the potato protein in one of these food products seven protein sources could potentially be substituted: soybean protein, yellow pea protein, beef protein, pork protein, chicken protein, egg protein and milk protein. The results of the CLCA show that when using the potato protein as an ingredient in a food product instead of other protein sources environmental impact can potentially be reduced. Most environmental impact can be reduced by substituting animal proteins by the potato protein. Therefore, from an environmental point of view, the most interesting food products to use the potato protein in as an ingredient are the food products where currently animal products are used in as the main source of protein.