Processing variables influence over characteristics of high oleic sunflower oil -saturated monoglycerides oleogels

CAMILA PALLA; ANABELLA GIACOMOZZI; MARÍA ELENA CARRÍN

Ghent

Congreso; 14th Euro Fed Lipid Congress; 2016

European Federation for the Science and Technology of Lipids e.V.

In a previous work we tested the ability of a commercial mixture of saturated MAG, Myverol (MV), to structure vegetable oils with different fatty acid composition (corn, soybean, sunflower and high oleic sunflower oil (HOSO)) (Giacomozzi et al., 2015). Results obtained in that study showed that oleogels formulated with HOSO required the lowest concentration of MV for gelation (2 %wt vs. 3 %wt for the rest of vegetable oils) and showed the highest oil binding capacity - at the same MV (%wt)- and great potential to reach rheological and textural properties similar to margarines. Furthermore, we also found evidence that the preparation conditions of the oleogels affected their characteristics. In the present research, different processing conditions to obtain oleogels from HOSO and MV are explored with the aim to development a fat with similar rheological and textural characteristics to margarine. The influence of specific parameters of the preparation ? the concentration of Myverol (MV (%wt)), the preparation temperature (TP), the speed of agitation (SA) and the cooling temperature (TC) ? has been studied on selected response variables. These were: OBC, oil binding capacity; textural parameters as: H, hardness, CO, cohesiveness, AD, Adhesiveness and, FR, fracturability; rheological parameters as Tg, gelation temperature, G´, elastic modulus and, η*, complex viscosity. The latter two responses were evaluated by means of mathematical models using their fitted parameters. In order to evaluate the effect of experimental factors on the responses, with a minimum number of trials, an incomplete factorial design of four factors with three levels (Box?Behnken) was applied. A fitting model for each response was obtained and a multi-response optimization was made to with the aim of finding the optimal preparation conditions for the oleogels. The use of optimization procedures to obtain a product with certain characteristics is essential in the field of food engineering. The multi-response optimization was carried out using a desirability function D, a function that optimizes various responses simultaneously obtaining the best balance between them. This methodology simplifies the experimental analysis by converting a multiple response optimization problem into a single response that is easier to interpret (Ferreira et.al, 2007; Silva et al., 2013). So, one innovative aspect of the present contribution is the application of this technique to obtain oleogels with mechanical properties similar to margarines. To sum up, this contribution intends to achieve a full understanding of the effect of main parameters of oleogels preparation. Likewise, it want take advantage of multi-objective optimization to produce oleogels with high oil binding capacity - strong gel network - and to get rheological and textural properties close to that of a commercial margarine.