TY - JOUR
T1 - Extrusion induced low-order starch matrices
T2 - enzymic hydrolysis and structure
AU - Zhang, Bin
AU - Dhital, Sushil
AU - Flanagan, Bernadine M.
AU - Luckman, Paul
AU - Halley, Peter J.
AU - Gidley, Michael J.
PY - 2015/12/10
Y1 - 2015/12/10
N2 - Waxy, normal and highwaymen maize starches were extruded with water as sole plasticizer to achieve low-order starch matrices. Of the three starches, we found that only high-amylose extrudate showed lower digestion rate/extent than starches cooked in excess water. The ordered structure of high-amylose starches in cooked and extruded forms was similar, as judged by NMR, XRD and DSC techniques, but enzyme resistance was much greater for extruded forms. Size exclusion chromatography suggested that longer chains were involved in enzyme resistance. We propose that the local molecular density of packing of amylose chains can control the digestion kinetics rather than just crystallinity, with the principle being that density sufficient to either prevent/limit binding and/or slow down catalysis can be achieved by dense amorphous packing.
AB - Waxy, normal and highwaymen maize starches were extruded with water as sole plasticizer to achieve low-order starch matrices. Of the three starches, we found that only high-amylose extrudate showed lower digestion rate/extent than starches cooked in excess water. The ordered structure of high-amylose starches in cooked and extruded forms was similar, as judged by NMR, XRD and DSC techniques, but enzyme resistance was much greater for extruded forms. Size exclusion chromatography suggested that longer chains were involved in enzyme resistance. We propose that the local molecular density of packing of amylose chains can control the digestion kinetics rather than just crystallinity, with the principle being that density sufficient to either prevent/limit binding and/or slow down catalysis can be achieved by dense amorphous packing.
KW - Enzyme-resistant starch
KW - Extrusion
KW - High-amylose starch
KW - In vitro digestion
KW - Local molecular density
UR - http://www.scopus.com/inward/record.url?scp=84939812911&partnerID=8YFLogxK
U2 - 10.1016/j.carbpol.2015.07.095
DO - 10.1016/j.carbpol.2015.07.095
M3 - Article
C2 - 26428150
AN - SCOPUS:84939812911
SN - 0144-8617
VL - 134
SP - 485
EP - 496
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
M1 - 10197
ER -