Chemically Modified Potato Starch as a Source of Nutritional and Non-nutritional Components

Abstract

Chemical modification of starch for food purposes is strictly limited in terms of the type of chemical reactions, the kind of modifying agents, the degree of substitution as well as the level of contaminants. Commonly applied chemical reactions include only three types, i.e. oxidation, esterification and etherification. Influence of chemicallymodified starches on a biological processes occurring in a human body seems to be interesting, especially as a source of the substances indispensable for the course of various metabolic processes. The study was aimed at answering a question: whether or to what extent the commercial preparations of potato starch, obtained upon chemical modification, would constitute a source of macro- and microelements and starch resistant to α-amylase hydrolysis, as components affecting physiological properties in a human body. Industrially obtained native potato starch as well as it food grade modified starches, were studied: oxidised starch (E 1404), acetylated starch (E 1420), and acetylated distarch adipate (E 1422). Protein content was determined with the Kjeldahl method. Resistant starch (RS) content was estimated according to the method described by Champ et al. (1999) and amylose content according to Morrison and Laignelet method (1983). The assay of individual elements content in the native and chemically-modified potato starch was carried out using the atomic absorption spectroscopy (AAS) method. Native and chemically-modified potato starch were characterised by different contents of amylose (from 20 to 31% d.m.) and a RS fraction (from 74 to 77% d.m.). All type of the investigated chemically-modified potato starch appeared to be a good source of elements, however the highest contents of phosphorus and potassium were found in native potato starch. Oxidised starch (E 1404) was the best source of macroelements (calcium and magnesium) and microelements (copper, manganese and zinc), as compared to the other investigated starches. Therefore, the application of the investigated chemically-modified potato starch may prove favourable not only due to their functional properties but also a source of RS and minerals.