Response surface analysis: effect of preparation conditions on rheological properties and oil retention of high oleic sunflower oil-saturated monoglycerides oleogels

ANABELLA GIACOMOZZI; CAMILA PALLA; DIEGO GENOVESE; MARIA ELENA CARRIN

Cordoba

Congreso; Congreso Internacional de Ciencia y Tecnología de los Alimentos 2016; 2016

In the last years, consumption of trans and saturated fats have been shown to have deleterious effects on humans´ health. Nowadays there is a clear trend towards the development of new and healthier food products to replace these types of fats. Oleogels may represent a promising alternative to achieve these requirements. An oleogel can be defined as a system comprising liquid oil that is physically entrapped in a network of self-assembled gelator molecules, which are added at low concentrations. In this work, oleogels produced from high oleic sunflower oil (HOSO) and a mixture of saturated monoglycerides (Myverol, MV) were formulated in order to evaluate the effect of the preparation conditions on their rheological properties and the oil binding capacity (OBC). Likewise, it was tried to obtain a material similar to margarine. With the aim to evaluate the influence of the concentration of MV, the preparation temperature, the speed of agitation, and the cooling temperature on OBC and the most representative rheological parameters, an incomplete factorial design of four factors with three levels (Box-Behnken) was applied. Rheological measurements were carried out by dynamic oscillatory test on oleogel cylindrical samples and OBC was determined by centrifugation.The obtained results show that the MV concentration and the cooling temperature were the most significant factors over each response analyzed. Related to the OBC values, all the oleogels prepared show a high value (ranged from 87.28% to 99.84%), indicating the formation of a strong gel network. The % OBC was found to rise with an increase in the amount of MV up to certain extent (~11%) in which the maximum value physically possible for OBC is reached. Further increase in MV keeps this value. It can be noticed that, when oleogels with concentration of MV above 10.5% are formulated it is possible to perform the cooling step in an increasingly wide range of temperature reaching, in all the cases, oleogels with maximum retention of oil. With regards to rheological properties, as the MV concentration increased, the elastic modulus, G´, showed a significant increase. Additionally, it was observed that the preparation conditions that generated oleogels with the highest G′ value also produced oleogels with the highest complex viscosity, η*. For the proposed design, the obtained products showed values of log G´ and η* close to margarine ones.In conclusion, these results indicate that using appropriate models and optimization tools is possible to produce oleogels with similar rheological properties to margarine.