Preparation And Application Of Several Compound Modified Starch

Due to its abundance, renewability and relatively low cost, starch is often used to prepare porous starch with adsorptive characteristics. Many developments have been reported concerning methods of preparing porous starches, such as ultrasonic and enzyme treatment. Because of their relatively high specific surface areas, porous starches have been used as adsorbents for methylene blue and oil and as carriers for flavorings and drugs. Importantly, moderate gelatinization may be an effective means of improving the adsorption efficiency of porous starch, as the limited swelling and loss of crystallinity incurred during gelatinization should favor their adsorption ability. Proanthocyanidins, a group of polyphenolic bioflavonoids with differing chemical structures, pharmacologies, and characteristics, are widely available in cereals, legume seeds, fruits, and fruit juices. These compounds have recently attracted increasing attention due to their strong antioxidative activity. However, proanthocyanidins can be easily oxidized when exposed to oxygen during processing or storage. Microencapsulation has been found to be an effective method for protecting anthocyanins.The present work aimed to develop a high absorbent corn starch and evaluate its adsorption of grape seed proanthocyanidins (GSPs). The resulting morphology, structure, and properties strongly depended on the order of the enzymolysis and gelatinization steps. During gelatinization, the pores in the enzymolysis starches shrank, and some disappeared. Neither enzymolysis nor gelatinization changed the basic chemical structures of the starch. However, the crystallinity was increased by enzymolysis and decreased by gelatinization. Furthermore, the reduction in crystallinity decreased the enthalpy change (ΔH) and increased the peak temperature (7p). The limited swelling upon gelatinization favored the diffusion of water molecules into the starch matrix and increased the water absorbability of the starches. A pseudo-first-order kinetic model accurately described the adsorption of porous-gelatinized starch towards GSPs (R~2> 0.995). The porous-gelatinized starch showed the best adsorption capability (qe=18.890±0.084 mg/g) and a relatively low desorption tendency (49%) towards GSPs. Thus, this starch may be used as an effective adsorbent in order to improve the utilization efficiency of GSPs and maintain their antioxidant activity.