Exploring the Potential of an Industry-Scale Microfluidizer for Modifying Rice Starch: Multi-Layer Structures and Physicochemical Properties

The modification effects of industry-scale microfluidizer (ISM) technology on small-sized rice starch remain unknown. This study systematically evaluated the effects of ISM treatment on the structural characteristics (granular morphology, crystallinity, and short-range order) and physicochemical properties (thermal, pasting, and rheological properties) of rice starch. Scanning electron microscopy (SEM) analysis revealed that ISM treatment induced the aggregation of starch granules, leading to an increase in particle size. Furthermore, ISM treatment resulted in starch damage, as evidenced by an increase in the damaged starch content from 4.25% to 17.99%. X-ray diffraction (XRD) analysis found that the relative crystallinity decreased from 29.01% to 20.74%, and Fourier-transform infrared (FTIR) spectroscopy implied that the absorbance ratio of 1047 cm^-1/1022 cm^-1 decreased from 0.88 to 0.73, indicating the disorganization of long-range crystalline structure and short-range ordered structure. Differential scanning calorimetry analysis demonstrated that ISM treatment reduced the gelatinization enthalpy of rice starch, with a gelatinization degree reaching 31.39%. Rapid visco analyzer (RVA) measurements indicated that ISM treatment increased the pasting viscosity of rice starch. However, the effect of ISM treatment on the dynamic rheological properties was minimal, with a slight enhancement in the loss modulus, while in-shear structural recovery rheology showed no significant impact on the ability of starch gels to recover their original structure. These results suggested that ISM technology effectively modified rice starch, leading to a disrupted structure, increased viscosity, and preserved gel network structure. This approach offers a novel strategy for the application of industry-scale microfluidizers in the development of rice-based products.