In-vitro enzymatic testing method and digestion mechanism of cross-linked wheat starch.

• Main Authors: Shukri, Radhiah, Seib, Paul A., Maningat, Clodualdo C., Shi, Yong Cheng
• Format: Book Section
• Published: John Wiley & Son 2013
• Online Access: http://psasir.upm.edu.my/id/eprint/31325/

This chapter focuses on the in vitro digestion behaviour of cross-linked (CL) wheat starch at various time intervals, the progressive changes of CL wheat starch granules during the in vitro digestion and the mechanism of the digestive enzymes during the digestion period in AOAC Method 2009.01. The resistant starch (RS) value obtained at 16 hours was lower than the RS content measured by the Englyst Method and AOAC Method 991.43. Microscopic and scanning electron microscope (SEM) results of the indigestible residues collected at the predetermined times showed progressive degradation of CL wheat starch granules. Some starch granules remained intact, which explained the comparable differential scanning calorimetry (DSC) data for CL wheat starch at all incubation times. The mechanism of enzyme attack on the CL wheat starch was exo-corrosive, as identified by the surface erosions and the non-existence of pinholes on the granules.