Effects of storage temperatures and annealing conditions on the structure and properties of potato (Solanum tuberosum) starch

Altering structure and enzymatic resistance of high-amylose maize starch by irradiative depolymerization and annealing with palmitic acid as V-type inclusion compound

This study explored a new physical modification approach to regulate enzymatic resistance of high-amylose starch for potentially better nutritional outcomes. High-amylose maize starch (HAMS) was subjected to chain depolymerization by electron beam irradiation (EBI), followed by inducing ordered structure through annealing in palmitic acid solution (APAS). APAS treatment significantly promotes the formation of ordered structure. Starch after the combinative modification showed up to 5.2 % increase in total crystallinity and up to 1.2 % increase in V-type fraction. The EBI-APAS modification led to increased gelatinization temperature (from 66.1 to 87.6 °C) and reduced final digested percentage under in vitro stimulated digestion conditions. The moderate extent of depolymerization resulted in higher enzymatic resistance, indicating that the extent of depolymerization is crucial in EBI-APAS modification. Pearson analysis showed a significant correlation between gelatinization onset temperature and digestion kinetic parameter (k1, rate constant of fast-phase digestion). Overall, the result suggests that ordered structures of degraded molecules induced by the combinative modification contribute to the enzymatic resistance of starch. This study sheds lights on future applications of EBI-APAS approach to regulate multi-scale structures and nutritional values of high-amylose starch.

Assessment of the Physico-mechanical, Chemical and Colour Characteristics of Potatoes Depending on Tuber Size and Cultivar

In this study, four tuber sizes (28S1 45mm, 45S255mm, 55S365 mm and S465 mm) and three potato cultivars (Jelly, Milva and Sante) were used to assess the variations of physico-mechanical, chemical and colour properties depending on tuber size and potato cultivars. Physico-mechanical properties (geometric mean diameter, sphericity, surface area, bulk and tuber densities, volume, static coefficient of friction, puncture force and deformation), chemical properties (pH, total acidity [TA] and total soluble solid content [TSSC]), and colour characteristics (L, a, b) were determined. The physico-mechanical (geometric properties and puncture force) and chemical properties of potatoes were significantly affected by tuber sizes and cultivars, respectively. pH, TA and TSSC of potato tuber were higher in Milva, TA was higher in Jelly and TSSC was higher in Sante than in those of the other cultivars, respectively.