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

Abstract

a b s t r a c tThis study was aimed to assess the role of lysophosphatidylcholine (LPC) in the development of slowly digestible starch (SDS). 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• C and subjected to enzyme hydrolysis by porcine pancreatic ␣-amylase at 37• 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.

Imaging inclusion complex formation in starch granules using confocal laser scanning microscopy

“…The core of the granules remains dark, inferring that the lipid‐dye molecules do not interact with the inner structures of the granules due to the protective coating generated by the lipid‐dye molecules already linked to the outer part of the starch granule, or that penetration is hindered by their bulky size and presence of the polar head. From this evidence, we concluded that in the case of un‐gelatinized potato starch granules lipid‐dye molecules at low concentration selectively complex with the outer amylose chains of the granules, as previously reported by our group as well as others .…”

“…Among others, the amylose‐lipid inclusion complex has been demonstrated to have an influence on the staling . Recently, the inclusion complex formation between amylose in native wheat starch and lysophosphatidylcholine (LPC) was reported, underlying the effects of such inclusion on the structural properties and the susceptibility to amylase of starch .…”

Effect of food additives on starch retrogradation: A review

“…Hydrophobic complexing reagents (such as fatty acids) can remain within the helix through van der Waals forces between lipids and the adjacent carbon–hydrogen of amylose . Meanwhile, the quantity and stability of starch–lipid complexes might be determined by the starch category, amylose chain length, nature of the lipid, solvent, and processing conditions . Starch–lipid complexation might be better assessed by a joint experimental and molecular mechanics approach because amylose–vanillin complexation has been assessed by experimental and theoretical analysis and computational techniques have been employed to fundamentally understand the behavior of helically structured amylose in water/DMSO mixtures .…”

Assessing the susceptibility of amylose–lysophosphatidylcholine complexes to amylase by the use of iodine

“…The influence of amylose inclusion complexation with LPC on the functional properties and thermal transitions of wheat starch was previously reported. In addition, a lower susceptibility to α‐amylase digestion due to amylose–LPC complexation was proven. However, it is still unknown if the amylose–LPC complexes remain stable during enzyme hydrolysis, e.g., if the LPC chains remain inside the amylose helix.…”