A Novel Technique to Characterize and Quantify Crystalline and Amorphous Matter in Complex Sugar Mixtures

Abstract

Sugar-rich foods are the complex mixtures of different carbohydrates in amorphous and crystalline forms. They are mostly not in equilibrium, and transition from amorphous form to crystalline form is very likely during their storage. It is essential to know the crystalline/amorphous fraction of sugars to study these undesirable changes. The existing techniques are not adequate owing to the nonideal interactions among these sugars. In this work, we propose a novel technique, which first segregates crystals from the amorphous matter by dispersing the food material in an appropriate solvent. This is followed by separation of crystals by filtration, and further quantification and characterization by high-performance liquid chromatography, X-ray diffraction, differential scanning calorimeter and microscopy. Non-centrifugal sugar and fondant, which are mixtures of sucrose, glucose and fructose, are chosen as representative examples to demonstrate the efficacy of the proposed method. On an average, 70–90% of the sucrose in NCS samples was found to be in crystalline state.