Relationship between sorption characteristic and selected functional properties of chemically modified waxy maize starches

The aims of this study were to evaluate the effect of chemical modification of waxy maize starch on its sorption, pasting properties, and in vitro digestibility, and to investigate the relationships among tested properties. The research materials were octenyl succinate, acetylated, oxidized, and acetylated‐oxidized starches. Starch acetylation and octenyl succinylation decreased amount of moisture content adsorbed above 0.4 water activity. For all tested starches, the bound adsorption predominates over free adsorption. Esterification with octenyl succinic or acetic anhydrides increased pastes hot paste and final viscosities. The rapidly digestible starch content decreased after performed modifications of waxy maize starch. Correlation analysis showed that peak viscosity and breakdown parameter of starch pastes were largely dependent on the properties of sorbed water. Ratio of free to bound water (F/B) at different water activities correlated with the setback values and contents of slowly digestible and resistant starch fractions. PRACTICAL APPLICATIONS: Generally, both sorption and functional properties of starch are modified in order to functionalize the polymer to meet specific requirements in the areas of food production and preservation. The research was aimed not only to investigate the sorption and functional properties of chemically modified starches, but also to find a relationships between the obtained results. Knowledge of these relationships can be used to formulate composition of food product, optimize processing parameters and select proper storage conditions to prevent product failure. On the basis of obtained results it was revealed that octenyl succinate and acetylated‐oxidized waxy maize starches exhibited lower amount of moisture content adsorbed at aw < 0.4. Therefore, these starches may be useful for processing and storing of low‐moisture starchy foods. Moreover starches with lower water absorbability form more stable gels. Obtained findings may be an useful tool for estimating the functional properties and the critical moisture contents during starchy food storage, that can assist to improve shelf‐life of stored products.