TAILORING PROPERTIES OF MIXED-COMPONENT OLEOGELS: WAX AND MONOGLYCERIDE MIXTURES AS STRUCTURING AGENTS IN FLAXSEED OIL

Face to the warnings around the consumption of saturated, trans or even interesterified fats, concerning their harmful effects to health, alternatives have been sought for soft materials envisioning food applications. Oleogels appear as emerging technology meeting both nutritional and technological functionalities. Thus, the aim of this work was to develop and evaluate semi-solid systems from fatty acid derivative oleogelator combined wax in a highly polyunsaturated vegetable oil. In this study, berry wax (BEW) and glycerol monostearate (GMS) were used as oleogelators and flaxseed oil (FXO) as organic solvent. Oleogels were formed by heating the oil and oleogelator(s) mixture with further cooling and storage at 5 or 25°C. Systems were characterized by i) rheological measurements using a stress-controlled rheometer (Anton Paar, Austria); ii) microstructure by means of polarized light microscope (Olympus, USA) and iii) oil binding capacity (Blake; Marangoni, 2015). Monocomponent BEW-based oleogels were formed in FXO (G’ = 3006.67 ± 162.58 at 25 ºC), but elastic features were reduced when BEW was mixed with GMS (G’ = 1050.00 ± 26.46 at 25 ºC). Storage at lower temperature strengthened the gel (G’ = 15700.00 ± 1385.64 for GMS0:100BW and 3513.33 ± 697.45 for GMS25:75BW at 5 ºC), matching with the presence of smaller crystals and a denser network depicted by microscopy images. Moreover, it may have favored oil entrapping within three-dimensional crystalline network, confirmed by the excellent ability to retain oil, with no oil release for GMS0:100BW and 96.67 ± 1.24% of initial oil loading was maintained for GMS25:75BW. In this sense, BEW molecules could properly arrange themselves in the bended chains of FXO, while the reduction of BEW and the addition of GMS resulted in negative interaction, impairing the complete network organization. Thus, the understanding of ingredient engineering in oleogel technology opens the opportunity to design of desired gel properties.