Consider a plant oil based margarine production. The basic ingredients used are two types of oils (saturated and unsaturated), aromas and  emulsifier both solubilize in water. The result is a product that is neither wholly liquid nor wholly solid but rather a semi-solid.

Given the densities of the oils at different temperatures table 1 Answer the following questions:

1. Determine the surface tension of both oils at each temperature. Explain and justify the surface measurement method that you would apply. Present the formula with the meaning of each  variable and the surface tension values.(Perform calculations  and analyze practical situation in terms of interface science principles (i.e. Young’s law, The laplace law,  Hamakers law)
2. Represent in excel a plot diagram the relation between surface tension and temperature. Explain why there is a change of surface tension of each oil with temperature. (Analyse practical engineering situations in the field of surface tension concerning adhesion, cohesion, wetting – )
3. How would you explain the decreasing of surface tension when you mix the oils with emulsifier, at 60C? (Discuss changes in food emulsions in the  context of interfacial engineering (i.e. emulsification, coalescence)
4. Consider margarine enrichment with sterols. How would you process this new product? Include in your answer the explanation of the new structure of this margarine and how the addition of sterols changes the recipe. (Discuss changes in food emulsions in the  context of interfacial engineering (i.e. emulsification, coalescence)