Evidence of starch inclusion complexation with lactones

Starch, in particular the linear amylose, is able to form inclusion complex es with a wide spectrum of ligand molecules, among them flavor compounds. T he complexing ability of a homologous series of gamma- and delta -lactones with potato starch was followed by amperometric iodine titration, different ial scanning calorimetry, and wide-angle X-ray diffraction measurements. La ctones with a Linear chain of a size greater than or equal to C-5 form incl usion complexes with starch, whereas lactones with a short linear chain, su ch as gamma -heptalactone, show poor complexing ability. The thermal stabil ity of starch-lactone complexes increases with increasing chain length of t he lactone. In general, lactones induce tl;e formation of V-h helices. Only delta -decalactone complexes with starch were not definitely identified as V-h amylose helices. Complexation of starch dispersions with lactones indu ce turbidity and gelation or phase separation, both phenomena being the res ult of microphase separation.