SummaryMonoglyceride concentrates of high purity can be readily prepared by molecular distillation. Their properties are, in general, about what would be expected from the high content of monoglycerides and absence of catalyst.The interfacial tension lowering produced by monoglycerides is essentially proportional to the monoester content of the monoglyceride product. In a water absorption test the unsaturated fatty acid monoglycerides are considerably more active than the monoesters of saturated fatty acids.