Salad Dressing Case Study

DISCUSSION The flow curve of salad dressing with different oil used was presented in Fig 1-3. Fig 1 showed the flow curve of salad dressing with mixed oil, while the Fig. 2 showed the flow curve of salad dressing with soybean oil and Fig. 3 is the flow curve of salad dressing with virgin olive oil. Based on the graphs, the salad dressing exhibit a pseudoplastic and shear-thinning behavior as characterized by the yield stress and time. Salad dressing is an oil in water emulsion that the droplets are stabilized by forming network and aggregation based on the adsorption characteristic. When the shear rate increase, the emulsion will deform very fast as the aggregated particle rupture and lower resistance to the flow. Therefore, the higher the shear rate, the higher the shear stress due to the free moving properties and the lower the viscosity. The flow curve of all the

Based on Table 3, there is no significant difference between the rheological parameter and different type of oil used in salad dressing. Ones of the possibilities that contributed to this outcome were the oil used in the salad dressing are all polyunsaturated and high oxidative stability, therefore they behave similarly in the emulsion. The other reason supporting the outcome was the cake mixer was used to blend the salad dressing prepared instead of passing through the high shear homogenizer so the result obtained might not be that accurate and reproducibility. In between, there is less study have been carried out on the effect of oil used in salad dressing in term of rheological properties. Most of the studies were focusing on the amount of fat content, stabilizer and emulsifier used in the preparation of salad dressing and all of the parameters were significantly influenced the rheological parameters (Wendin and Hall,