Not long ago, the processing and engineering technology research team of the Institute of Fragrant Drinks of the Chinese Academy of Thermal Sciences made important progress in exploring the impact of different soluble pectin in bread fruits on starch digestibility.

　　Breadfruit ( Artocarpus altilis ) is a tropical cash crop that is rich in nutrients and has a high yield, with potential positive effects on diabetes, hypertension, obesity and other diseases. Studies have shown that the glycemic index of bread and fruit flour is lower than that of wheat flour and rice flour, and bread and fruit flour has a certain anti-digestible effect and relieves blood sugar increase. Our previous research showed that breadfruit pectin had a significant effect on starch digestibility, but its influence mechanism was not yet clear. According to solubility, pectin can be divided into water-soluble pectin, chelating agent-soluble pectin and sodium carbonate-soluble pectin. Previous studies have mostly focused on the influence of pectin of different concentrations and molecular weights on starch gelatinization and digestibility. There are currently reports on the impact of pectin of different solubility on it.

　　Therefore, this study used instruments and methods such as rapid viscosity measuring instrument, Fourier transform infrared measuring instrument, differential scanning calorimeter, isothermal titration calorimeter, cold field emission electron scanning microscope and in vitro digestion method to study the effects of water-soluble pectin, chelating agent soluble pectin and sodium carbonate soluble pectin on the digestibility of bread fruit starch. The results show that all three pectin can inhibit starch digestion. The addition of chelating agent soluble pectin increased the resistant starch content from 8.18% to 18.07% , and the addition of sodium carbonate soluble pectin increased the slow digestion starch content from 22.55% to 35.24% . These three pectins have different methods and principles in inhibiting starch digestion. Water-soluble pectin combines with leaching amylose to form a film covering the surface of starch particles. However, chelating agent soluble pectin and sodium carbonate soluble pectin penetrate into the starch granules during gelatinization, blocking the pores on the surface of the starch granules, thereby reducing the digestibility of starch. The results of this study provide a theoretical basis for the development of low- GI foods for starch in special tropical crops such as bread fruit.

　 The related results were published in " Food Hydrocolloids " under the title " Effect of different solution pectin in breadfruit on starch digestibility " . The research was funded by the China Academy of Tropical Agricultural Sciences project, the basic scientific research business fees of central-level public welfare research institutes, the Hainan Provincial Science and Technology Talent Innovation Fund, and the Science and Technology Innovation Team of the National Tropical Agricultural Science Center of the Chinese Academy of Tropical Agricultural Sciences.