Ölmobilität in Haselnusspasten: Einfluss der Inhaltsstoffe und Prozesstechnik

Hazelnut pastes consist of sugar, cocoa, milk powder and ground nuts, which are dispersed within a quasi-continuous oil and fat phase mainly composed of hazelnut oil. The mobility of this oil fraction contributes to oil separation on the surface and oil migration within the matrix. The mechanisms underlying these phenomena, as well as the factors influencing them, are not yet fully understood.
The aim of this study is to investigate systematically how compositional and processing parameters affect oil mobility in hazelnut pastes. Specifically, the work examines (1) the effect of different physicochemical properties of oils and fats on oil mobility, (2) oil immobilization induced by solid particles typically present in nut pastes, (3) the influence of grinding and mixing processes on oil mobility in hazelnut pastes, and (4) the immobilization of hazelnut oil within oleogel networks.
The results show that oil mobility is influenced, on the one hand, by the composition of the ingredients – particularly the specific surface area, particle size and -shape, and surface hydrophobicity of the solids –, as well as the viscosity of oils. On the other hand, grinding and mixing conditions have a substantial impact on mobility in nut pastes. ... mehrThe effects of composition and processing cannot be considered independently, as they are closely interrelated. A finer grinding of pure hazelnut pastes increases oil mobility due to the destruction of oleosomes, whereas in hazelnut-sucrose or nougat pastes it leads to a smaller oil mobility as a result of the larger relative surface area and the formation of densely packed structures with entrapped oil. Furthermore, oleogelation represents an effective approach to reduce the mobility of hazelnut oil.
Across all model systems, oil mobility is primarily governed by two mechanisms: adsorption of oil onto surfaces of solids and physical entrapment or geometric hindrance within interparticle voids or densely packed particle structures. The interpretation of oil mobility measurements strongly depends on the investigated material system, the applied measurement method and the considered length scale.
The results of this work contribute to a deeper understanding of the mechanisms governing oil mobility in nut-based systems and provide a scientific basis for optimizing their stability and shelf life.