title: Chemical composition and nutritional value of protein concentrates isolated from potato (Solanum tuberosum L.) fruit juice by precipitation with ethanol or ferric chloride.
abstract: Effects of protein precipitators, ethanol and ferric chloride, on yield, resolubility, chemical composition and nutritional value of protein concentrates isolated from industrial potato fruit juice (PFJ) were studied. Optimum precipitating concentrations of ethanol and ferric chloride in PFJ were 4 M (23.1% v/v) and 20 mM (2% w/v), resulting in yield of 69% and 86.5% of total protein, respectively. Contents of total glycoalkaloids and potassium in both protein concentrates were significantly lower (P < 0.05) as compared with contents in PFJ dry matter. Both protein concentrates exhibited high nutritional value; values of essential amino acid index (EAAI) were 81.7% and 82.7%, respectively. Fraction of patatin proteins (39-43 kDa) represented with EAAI value of 86.1% the nutritionally improving protein component. Lipid acyl hydrolase activity of patatin family was not negatively affected by cooled ethanol precipitation. It can be thus suggested that biological and enzymatic activities of this protein family are utilizable after this type of precipitation.
authors.affiliation: Department of Plant Production, Faculty of Agriculture, University of South Bohemia, Ceske Budejovice, Czech Republic. vbartova@zf.jcu.cz
authors.forename: Veronika
authors.initials: V
authors.lastname: Bártová
authors.forename: Jan
authors.initials: J
authors.lastname: Bárta
mesh_terms: D000601:Amino Acids, Essential / Q000032:analysis; D001628:Beverages / Q000032:analysis; D002265:Carboxylic Ester Hydrolases / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011232:Chemical Precipitation; D002712:Chlorides; D000431:Ethanol / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D009753:Nutritive Value; D010940:Plant Proteins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D035281:Plant Tubers / Q000737:chemistry*; D011480:Protease Inhibitors / Q000032:analysis; D011198:Solanum tuberosum / Q000737:chemistry*
chemical_list: D000601:Amino Acids, Essential; D002712:Chlorides; D005290:Ferric Compounds; D010940:Plant Proteins; D011480:Protease Inhibitors; C043222:patatin protein, Solanum tuberosum; D000431:Ethanol; D002265:Carboxylic Ester Hydrolases; C024555:ferric chloride