Ultrasound assisted acid hydrolyzed structure modification and loading of antioxidants on potato starch nanoparticles

Abstract

Starch is second most abundant biomaterial available after cellulose but the intensity of research on starch is less compared to cellulose. It is a carbohydrate based polymer synthesized in plants for the storage of the energy. Major percentage of starch is being utilized by food industries as raw material for giving texture, flavor, gelling, fat replacement etc. and also has multiple applications in different area due to its biological origin and properties. Native starch possesses low shear stress, poor thermal properties and less digestion resistance and retro-gradation. Thus, it has to be modified using physical, chemical, enzymatic and/or genetic treatments. Physical and chemical modifications using ultrasound and acid hydrolysis is time-efficient and effective process. These economical treatments are predominant for production of digestion resistant starch with increased shelf-life and thermal properties. Ultrasound assisted acid hydrolyzed starch (potato) exfoliates the native starch and modifies the structural arrangement. On acid treatment the amorphous nature of starch converted to crystalline nature. The physical and structural properties of the native starch were enhanced. The digestibility and structure of the modified starch effects on the double helices structure of starch. The size of the starch particle was changed from 1596 nm (Conventional) to 80 and 42 nm on ultrasonication and acid hydrolyzed ultrasonication approaches respectively. The crystallite of the particles was evaluated from XRD analysis. From TEM analysis the starch nanoparticles were found to have spherical morphology.

Keywords: Acid hydrolysis; Crystallization; Starch modification; Starch nanoparticles; Ultrasonication.