This study was aimed at comparing selected properties of starch citrate obtained from native or retrogrades of potato starch at various temperatures (100, 130 or 160°C) and at various doses of reactant (10, 20 or 40 g per 100 g). Higher susceptibility to esterification was demonstrated for retrograded starch, whereas the degree of esterification of the produced esters varied considerably (1.4 to 10.0 g per 100 g preparation) and was increasing along with increasing roasting temperature and dose of citric acid. The process of pasting occurred only in the esters obtained at a temperature of 100°C, which resulted in a significant decrease in swelling power and solubility in water of the citrates produced at higher temperatures. The resultant starch citrates were characterised by significant resistance to amylolysis (ranging from 22 to 100 g per 100 g). There was observed an increase in starch resistance along with the increase in the acid dose and roasting temperature. All analysed properties of starch citrates were not correlated with the degree of esterification, but appeared to depend on the roasting, which may point to a significant effect of this factor on the mechanism of starch cross-linking with citric acid.

No abstract

No abstract

No abstract

Starch modification by chemical reaction is widely used to improve the properties of native starch. Modified by citric acid, starch is characterized by specific properties resulting from the presence of citrate residues and as a result of cross-linking starch. The chemicals used for preparing starch citrates are safe for human health and the natural environment compared to the harsh chemicals used for conventional modifications. Starch citrates are traditionally produced by heating starch–citric acid mixtures in semi-dry conditions or by a heat moisture treatment. The conditions of the modification process (roasting temperature, heating time, citric acid dose) and the botanic source or genotype of starch determine the degree of substitution and the properties of the obtained preparations. Changes of starch properties occurring during esterification lead to reduced relative crystallinity, resulting in a decrease in the affinity for water, the gelatinization parameters, and the viscosity of starch citrate. However, one of the most important outcome of the modification is the formation of resistant starch (RS), which has increased resistance to the action of amylolytic enzymes. Currently, new methods for producing starch citrates with improved functional and rheological properties while maintaining the highest possible content of resistant starch are being sought. The article presents an overview of recent studies on the production, properties. And applicability of starch citrates with special attention paid to their role as preparations of resistant starch (RS). The use of citric acid for modification of starch is better for the technology process, while using cross-linking is better than simply using esterification.