Binding of amino acids to hypochlorite‐oxidized potato starch

Abstract

AbstractNovel starch derivatives were prepared by derivatization of oxidized potato starch with amino acids in aqueous suspension. Potato starch was oxidized using sodium hypochlorite and then reacted with amino acids under mildly alkaline conditions. By analysis of increased nitrogen content and by means of confocal laser scanning microscopy, efficient binding of positively charged amino acids to oxidized starch molecules was confirmed. A degree of substitution (DS) of up to 0.015 was obtained using oxidized starch (degree of oxidation (DO) of up to 1.0%) and positively charged amino acids (2–5%, dry starch basis) at reaction conditions of starch/water ratio of 1:2–2.5, pH 10, 40°C, 30–60 min. The DS was positively correlated with the DO of the starch. Derivatization of oxidized starch using amino acids generally enhanced the influence of oxidation on starch pasting characteristics, perhaps showing interesting functional properties and potential industrial application.