The influence of amylose-LPC complex formation on the susceptibility of wheat starch to amylase

This study was aimed to assess the role of lysophosphatidylcholine (LPC) in the development of slowly digestible starch (SOS). The influence of LPC, on the enzymatic degradation of diluted 9% wheat starch suspensions (w/w) was investigated, using an in vitro digestion method. Wheat starch suspensions containing 0.5-5% LPC (based on starch) were heated in a Rapid Visco Analyser (RVA) till 95 degrees C and subjected to enzyme hydrolysis by porcine pancreatic a-amylase at 37 degrees C for several digestion periods. In vitro digestion measurements demonstrated that complexing starch with 5% LPC leads to a 22% decrease in rate of reducing sugar compared to the reference while the samples containing 0.5% LPC showed an equal digestibility comparable to the control. A clear decrease in the formation of reducing sugars was observed in presence of 2-5% LPC, since the results after 15 min digestion imply the formation of SDS due to the formation of amylose-LPC inclusion complexes. The DSC measurements proved the presence of amylose-LPC inclusion complexes even after 240 min digestion demonstrating the low susceptibility of amylose-V complexes to amylase. (C) 2013 Elsevier Ltd. All rights reserved.