engleski

Isolation of starch from two wheat varieties and their modification with epichlorohydrin

The aim of this research was determination of influence of wheat variety and modification with epichlorohydrin on starch properties. Starch was isolated from two wheat varieties: “Golubica” and “Srpanjka” and modified with different concentrations of epichlorohydrin (0.1, 0.3 and 0.5 v/w). Both native and modified starches were characterized. Results showed similar characteristics of native wheat starches. Modification with epichlorohydrin increased temperature of gelatinization, but gelatinization and retrogradation enthalpy were affected by the extent of the chemical reaction between starch and epichlorohydrin, due to differences in reactivity between wheat starch varieties. Maximum viscosity decreased, as well as break-down and setback values. Swelling power and solubility were also decreased by modification, while paste clarity and freeze-thaw stability were influenced differently, due to different extent of the chemical reaction between different starch varieties and epichlorohydrin. Colour of starch wasn’t significantly altered by modification. Digestibility of starches can be reduced by proper selection of epichlorohydrin concentration used for modification.

wheat starch; epichlorohydrin; DSC; RVA; paste clarity; freeze-thaw stability; resistant starch

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