Monoglycerides in Oils

Monoglycerides (MG) and their organic acid derivatives are the most commonly used polar lipids in food products and their phase behavior is associated with their functional effects in many products. Apart from several studies in MG and MG-aqueous systems, there have been surprisingly few studies in MG-oil, which is an important substance in the food industry, especially for forming cream. The study presented in this chapter is primarily devoted to the phase behavior of MG in oils; it discusses the results of mixing additional component colloids, such as water, with these composite systems and presents also some fundamental discussions of general lipid morphology. The chapter briefly reviews the fundamentals of pure MG and MG dispersed in water and then concentrates on the mixtures of MG and oils. It also examines relevant theories addressing the phase behavior. In addition to the classical questions raised in surfactant solutions, such as phase diagrams, rheological properties and the microstructure of phases, it also focuses on aging and metastability of phases, quantified by changes in melting enthalpy and in infrared spectra that reflect the changes of hydrogen bonding pattern.