Physical properties of organogels and water in oil emulsions structured by mixtures of candelilla wax and monoglycerides

Organogelation is a promising alternative to provide structure and texture to vegetable oils and stability to solid-like water-in-oil emulsions. Within this framework, we investigate the effect of monoglycerides (MG; 0%-0.5%) in the microstructure, thermal and textural behavior of organogelled emulsions developed with candelilla wax (CW; 0.5%-4%), safflower oil, and water (20%). The emulsions were prepared by homogenization (200 bars) at 65 °C, cooling to 45 °C or 47 °C (Tout), and then storage at 5 °C for 24 h. To evaluate the effect of shearing and water addition we also developed CW-MG organogels (i.e., no water added) under similar conditions. Both systems were analyzed for solid phase content (SPC), texture, and microstructure. Independent of Tout, as CW and MG concentration increased in both systems the SPC increased also (P < 0.05). In the organogelled emulsions with 3% CW, independent of MG and Tout, hardness (2245.7 ± 270 gf∗mm) was ≈ 80% of the organogels' hardness (2861.0 ± 255.0 gf∗mm). This behavior was associated with the lower SPC (≈ 20%) present in the emulsions. Additionally, the microphotographs of the emulsions showed that water droplet size decreases as MG concentration increased. This effect was partly associated with the interfacial effect of the MG, but mainly with the lower extent of coalescence resulting from the droplet immobilization by the crystal network developed by CW. The lower texture and the decrease in water droplet size as MG concentration increased were not observed in the 2% CW emulsions, particularly at MG concentrations higher than 0.25%. This in spite the 2% CW-MG organogels had higher SPC than the corresponding emulsions (P < 0.05). These results suggested that MG affected the inter-crystal interactions in both the organogels and the emulsions. This phenomenon became more significant as the MG concentration increased with respect to the crystal mass.