Pregelatinized starch was made from indica rice starch using a so-called "improved extrusion cooking technology" (IECT) under 30%-70% moisture content. IECT-pregelatinized starch (IPS) had higher water solubility and water absorbability compared to native starch at low temperature. For pasting properties, the breakdown and setback viscosities of IPS were significantly (p<0.05) lower than native starch, suggesting improved gel stability and reduced short-term retrogradation. The rice starch granules lost their integrity in IPS, and formed a honeycomb-like structure with increased moisture content in the raw material. These properties can be explained in terms of molecular structural features, particularly the large reduction in the size of molecules, but without significant changes in the chain-length distributions of amylopectin component, and no significant change in amylose fraction. These results indicate that IECT is suitable for preparing IPS with desirable water solubility and gel stability properties.

In many cultures, rice is let to cool for a while after cooking before being consumed, which results in some retrogradation of the starch. The in vitro digestibility of 16 cooked rice starches after extended cold (4 °C) storage, which leads to extensive retrogradation, was investigated from the perspective of their starch molecular fine structure. Size-exclusion chromatography (SEC) and fluorophore-assisted carbohydrate electrophoresis (FACE) were used to characterize the starch chainlength distributions (CLD) and whole molecular size distributions. The retrograded starch gel network was studied by differential scanning calorimetry and scanning electron microscopy. Pearson correlation analysis with in vitro digestibility revealed that the starch digestion rate was positively correlated with cell size and cell wall thickness within the formed gel network, which was mainly derived from the interactions of amylose short-medium chains and not strongly related to amylopectin molecular structure. This suggests that rather than just altering amylose content, modification of amylose fine molecular structure (e.g. increasing the amount of shortmedium amylose chains) can also slow rice starch digestibility.

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The effects of application of ultrasonic waves to recombined milk emulsions (3.5% fat, 7% total solids) and raw milk on fat destabilization and creaming were examined. Coarse and fine recombined emulsions (D[4,3]=9.3 μm and 2.7 μm, respectively) and raw milk (D[4,3]=4.9 μm) were subjected to ultrasound for 5 min at 35°C and 400 kHz or 1.6 MHz (using a single transducer) or 400 kHz (where the emulsion was sandwiched between two transducers). Creaming, as calculated from Turbiscan measurements, was more evident in the coarse recombined emulsion and raw milk compared to that of the recombined fine emulsion. Micrographs confirmed that there was flocculation and coalescence in creamed layer of emulsion. Coalescence was confirmed by particle size measurement. These results imply that ultrasound has potential to pre-dispose fat particles in milk emulsions to creaming in standing wave systems and in systems with inhomogeneous sound distributions.