Steady shear and transient properties of starch in dimethylsulfoxide

In Vitro Starch Digestibility, Rheological, and Physicochemical Properties of Water Caltrop Starch Modified with Cycled Heat-Moisture Treatment

This study focused on the effect of cycled heat-moisture treatment (cHMT) on the in vitro digestibility, rheological, and physicochemical properties of water caltrop starch. The amylose content increased significantly by cHMT, whereas damaged starch content decreased only in the groups with more than two cycles applications. cHMT generally increased the weight-average molecular weight, except for single cycle treatment which showed the reverse result. In thermal properties, the onset temperature (T0), peak temperature (Tp), and conclusion temperature (Tc) increased, while the enthalpy needed to complete the gelatinization was lowered by cHMT. Water caltrop starch paste showed less shear-thinning behavior with cHMT. Meanwhile, the viscosity and tendency to form strong gel were enfeebled with modification. cHMT significantly changed predicted glycemic index (pGI) value, especially in samples that underwent the most cycles of treatment, which showed the lowest pGI compared to native and other treatment. These results suggested that cHMT water caltrop starch was effectively modified and showed diversified properties.

Sugar Profile, Mineral Content, and Rheological and Thermal Properties of an Isomerized Sweet Potato Starch Syrup

Currently, corn is used to produce more than 85% of the world's high fructose syrup (HFS). There is a search for alternative HFS substrates because of increased food demand and shrinking economies, especially in the developing world. The sweet potato is a feasible, alternative raw material. This study isomerized a high glucose sweet potato starch syrup (SPSS) and determined its sugar profile, mineral content, and rheological and thermal properties. Rheological and thermal properties were measured using a rheometer and DSC, respectively. Sweet potato starch was hydrolyzed to syrup with a mean fructose content of 7.6 ± 0.4%. The SPSS had significantly higher (P < 0.05) mineral content when compared to commercial ginger and pancake syrups. During 70 days of storage, the SPSS acted as a non-Newtonian, shear-thinning liquid in which the viscosity decreased as shear stress increased. Water loss temperature of the SPSS continually decreased during storage, while pancake and ginger syrups' peak water loss temperature decreased initially and then increased. Further and more detailed studies should be designed to further enhance the fructose content of the syrup and observe its stability beyond 70 days. The SPSS has the potential to be used in human food systems in space and on Earth.