The aim of this research was to develop and characterize some bigels, in order to use them as a fat replacing systems in confectionery products. Preliminary studies were carried out to optimize the composition and formulate the bigel samples. Design-Expert statistic software was used to project the experiment using a combination of 3 factors: emulsification time [minutes], the rotations used for emulsification [rotations per minute] and the emulsifier type (Polysorbate 20/ Tween 80/ Lecithin). The effect of the factors and their interactions on the characteristics of the samples was also studied. The obtaining process of the bigels includes the distinct obtaining process of the hydrogel and oleogel. Xanthan gum was added to distilled water and the mixture were stirred at 300 rpm to produce the hydrogel. The oleogel was prepared by the direct method using refined sunflower oil and carnauba wax (10%) at 85 ℃ to ensure melting and complete dissolution. The oleogel was then added to the hydrogel and the mix was homogenized at high shear rate according to the design (23 samples). Bigels have a structured internal and external phases and combine the advantages of both phases. The samples were stored at 4 ℃ and subjected to analysis: texture profile analysis, rheological measurements, polarized light microscopy, FTIR, liquid binding capacity. All bigel formulations were stable and did not show phase separation, which indicated that the emulsifiers used were effective structuring agents at the chosen concentration (2%). In terms of texture analysis, P8 registered the highest hardness value- 16.28 N, followed by P23- 10.47 N and P17- 7.72 N, all samples being obtained with lecithin. The emulsifier type, the time and rotations used for homogenization significantly affect the hardness and the values were also influenced by the interaction between the rotations and the time used during sample preparation. The losses of liquid phases for all samples were below 11.24%. In order to determine the potential application, the samples were subjected to mechanical grinding to simulate the mixing process with the ingredients necessary to obtain a confectionery product and subsequently analyzed in terms of stability. Thus, sample P3 with Polysorbate 20 and sample P22 with Tween 80 were chosen due to their high stability, results that were also correlated with the texture profile. The replacement of conventional fats with the new bigels food systems, could be a viable alternative in the food technology in order to obtain nutritionally improved products.
OLEO-003: Designing of Bigels as Fat Alternatives in Confectionery Products
