Effect of different soluble pectin in breadfruit on starch digestibility

Breadfruit is rich in starch and pectin. The pectin can alter the digestion process of starch, however, the specific mechanism by which various soluble pectin impact starch digestion remains unclear. The effects of water-soluble pectin (WSP), chelating agent soluble pectin (CSP), and sodium carbonate soluble pectin (SSP) on the digestibility of breadfruit starch were characterized by means of RVA, FTIR, DSC, ITC, SEM and in vitro digestion. The results showed that the three types of pectin could inhibit starch digestion. The addition of CSP increased the resistant starch content from 8.18% to 18.07%, and the addition of SSP increased the slow-digested starch content from 22.55% to 35.24%. The three pectin have different ways in inhibiting starch digestion. They have different principles in inhibiting starch digestion. WSP binds with the dissolved amylose to form a membrane that covers the surface of the starch particles. However, CSP and SSP penetrate into the starch granule during the gelatinization process, blocking the pores on the starch particle surface, thus reducing the starch digestibility.