Interfacial tension of oil‐water systems containing technical mono‐ and diglycerides

Summary Technical mono‐ and diglyceride products have been prepared from cottonseed oil stearine, and the effectiveness of these products in lowering the interfacial tension at vegetable oil‐water interfaces has been investigated. When both monoglycerides and diglycerides are present in the oil phase, the surface activity of the is less than 1/100th that of the monoglycerides on a weight for weight basis; hence the interfacial tension is substantially a function of the monoglyceride content. The interfacial tensions against water of such oils as peanut, cottonseed, and soybean are practically the same, and their interfacial tensions are lowered by practically equal amounts for equal additions of a given monoglyceride preparation. A concentration of 1% of monoglycerides in the oil phase will lower the interfacial tension at the oil‐water interface to approximately one‐half that which is observed when no monoglycerides are present. A concentration of 6% of monoglycerides in the oil phase will lower the interfacial tension approximately to zero.