CHARACTERIZATION AMYLOS-FLAVOR COMPLEXES BY DSC AND X-RAY-DIFFRACTION

Amylose is able to form complexes with a variety of ligands such as fa tty acids, emulsifiers and flavour substances. The complex-forming mol ecules induce the formation of single amylose helices (V amylose). Sta rch complexation with flavour molecules is one of the mechanisms of fl avour retention in starch-containing food systems. Furthermore, the fo rmation of starch-flavour complexes modifies the texture of low-concen tration starch systems. In the present investigation, starch-flavour c omplexes were prepared by combining aqueous potato starch dispersion ( 2 g/100 g) with decanal and (-)fenchone respectively. The water-insolu ble ligands were introduced with the aid of lecithin as non-complexing emulsifier. Flavour molecules other than decanal and (-)fenchone were added directly or dissolved in ethanol. DSC measurements and X-ray po wder diffraction were carried out on freeze-dried samples. X-ray diffr action clearly showed the pattern of V amylose, indicating the formati on of complexes with different crystalline structures. Endothermic tra nsitions as shown by DSC correlated with the melting of the crystallin e amylose-flavour complexes. No correlation was found between the melt ing temperature measured by DSC and the crystallinity determined by X- ray diffraction.