Effect of Different Pre-Gelatinization Treatments on the Properties of Acidified Mung Bean Starch

Microwave radiation processing technology is an emerging technology with good penetration, uniform heating, and rapidity characteristics. After microwave wet heat treatment, the viscosity of starch decreased, and the gelatinization temperature changed the granule morphology, crystalline properties, and chemical structure of starch, resulting in changes in the physical and chemical properties of starch. It can effectively improve the sensory quality of food and prolong the shelf life of starch products. It is widely used in food, pharmaceutical, agriculture, and other industries. The pre-gelatinized starch showed irregular shape, rough surface, and apparent edges and corners. Moreover, the starch particles' crystal structure is destroyed, crystallinity decreased to 11.43%-14.91%, and no new groups are formed. The starch granules changed from an ordered structure to a disordered structure, and the order degree decreased to 0.998-1.025. The enthalpy decreased to 2.22-4.32 J/g, the gelatinization temperature increased to 88.53-94.43 degrees, and the viscosity decreased significantly. After pre-gelatinization, the amylose content decreased to 13.84%-16.25%. At 90 degrees, the solubility and swelling degree decreased to 2.48%-7.33% and 16.80%-17.81%, respectively. The freeze-thaw water precipitation rate increased to 41.92%-59.35%, the water-holding capacity increased by 3 times and transparency increased to 93.60%-95.84%.