Study On Physiochemical Properties And Adsorption And Inclusion Of Tea Polyphenol Of Non-crystalline Granular Starch

The non-crystalline granular corn starch was prepared with native corn starch and ethanol solutions by heat treatment. Effects of non-crystalline treatment on physicochemical properties of starch were studied. Non-crystalline granular starch on adsorption behavior of tea polyphenols was investigated and the effects of this modification on the nutritionally important starch fractions were also studied. Then tea polyphenols (TP)-non-crystalline granular starch complexes were prepared and the physical and chemical properties of TP-NCGS complexes were characterized. The digestion performance in vitro of two kinds of samples was determined. A new method of preparation of resistant starch was put forward according to TP having the characteristics of inhibiting amylase activity and the high content of SDS+RS in NCGS.The experimental results showed that the granulars of the NCSGs were kept integrated while the granules started to depress from the hilum region leading to substantial wrinkling on the surface. The solubility and swelling power of NCGS were increased comparing with native corn starch. The treated NCGS showed V-type X-ray diffraction patterns, its crystallinity was almost disappeared. The crystallinity of NCGS-92 was 2.1%. The thermal decomposed behavior showed that the mass loss was 303.2～306.2℃ and appeared at a higher temperature as the crystallization temperature increasing. The modification reduced RDS content but increased obviously the total SDS+RS content, the RDS levels of NCGS-88 decreased to 81.64%, while the SDS+RS levels increased to 18.36%. The digestibility in vitro experiments showed that the ratio of digestibility of NCGS was higher than native corn starch. The digestibility of NCGS-85 reached to 99.2%. The adsorption ability of NCGS was studied, the optimal conditions were:TP concentration was 4 mg/mL, the adsorption temperature was 25℃, the reaction time was 4 h. The maximum adsorption of TP by the NCGS-85 under the condition was 105.27 mg/g.The FTIR of TP-NCGS complexes analysis showed as the tea polyphenols addition and the crystallization temperature increased, some infrared characteristic peaks of TP was gradually obvious. Thermal analysis results showed that the weight loss ratio was 86.36%, 85.79% and 86.24%, respectively. In vitro digestion experiment showed that the digestibility of TP-NCGS complexes was 70.3%,73.0% and 74.5% which had a significant decrease comparing with NCGS.