Impact of oleogelation on the mobility of liquid oil

Abstract: The migration of oils and fats leads to quality losses in various food matrices (e.g. fat bloom formation on chocolate). Especially liquid oils such as hazelnut oil have a low melting point and are very mobile, as most of the fatty acids are unsaturated. In order to reduce the mobility of hazelnut oil, oleogels were prepared using different gelators like wax from sunflower seeds and mono-diglyceride crystals. Oleogels exhibit a semi-solid-like character, as they consist of a network in which the liquid oil is entrapped. The aim of this study was to investigate the restricted mobility of oil molecules in these oleogels.

The samples were studied with regard of their rheological properties, melting and crystallization behavior, oil binding capacity and oil mobility. With increasing gelator concentrations, oleogels showed an increase in gel strength, phase transition temperature and oil binding properties. Molecular diffusion measured by NMR reflects translational mobility. It provided evidence of a partially reduction of mobility via hindrance of the oil molecules in the gelator network below the melting temperature. The results show the potential of oleogels to affect oil mobility with the aim of reducing migration-induced quality losses such as fat bloom or oil syneresis.