Interaction between Amylose and β-Cyclodextrin Investigated by Complexing with Conjugated Linoleic Acid

Interaction between amylose, a common food component, and beta-cyclodextrin (betaCD), an often used food additive, was investigated by incorporating a third component of bioactive conjugated linoleic acid (CLA) that could form an inclusion complex with both amylose and betaCD. The existence of an amylose-betaCD interaction was first evidenced by a reduced thermal stability of amylose in the amylose-betaCD complex and a decrease of extractable betaCD from 60 to 51.40% after their complexation. The way of their interaction was then explored in a three-component system, in which the amount of CLA is high enough to oversaturate both amylose and betaCD. In comparison to the amylose-CLA and betaCD-CLA complexes, a self-assemblied amylose-CLA-betaCD three-component complex confirmed by differential scanning calorimetry (DSC), X-ray diffraction, and thermogravimetric analyses showed an in-between thermal stability, high acid stability, and the highest amylolytic digestibility (74.43%), which suggests that betaCD is likely sandwiched between the helical amylose chains in the amylose-betaCD complex. Therefore, betaCD can be used to manipulate the crystallization process of amylose to modulate food product quality, and the amylose-betaCD complex could also be applied to improve the delivery efficiency of CLA and other bioactive compounds.