Monoglycerides monolayers

Cornec, M., Narsimhan, G. (2000). Adsorption and exchange of (3-lactoglobulin onto spread monoglyceride monolayers at the air-water interface. Fangmuir, 16, 1216-1225. 

Ratino, J.M.R. and Carrera, C. Structural, topographical, and shear characteristics of milk proteins and monoglyceride monolayers spread at the air-water interface, Langmuir, 20, 4530, 2004a. 

Rodriguez Patino, J.M., Rodriguez Nino, M.R., Carrera, C., Cejudo, M. (2001b). Whey protein isolate-monoglyceride mixed monolayers at the air-water interface structure, morphology, and interactions. Langmuir, 17, 7545-7553. 

Force-distance curves between monolayers of monoglycerides, monoolein and monopalmitin, deposited on hydrophobically modified mica were determined using the surface force technique. It was demonstrated that the interactions between the monoglyceride films change with the state of the hydrocarbon chain, the headgroup being the same. In transition from the more condensed state to the more fluid state the attraction between the monolayers decreased whereas the repulsion increased [100]. 

From a systematic study focused on fhe tt-A isofherm of protein-LMWE mixed monolayers (including fhe application of fhe additivity rule on miscibility and the quantification of inferacfions between monolayer components by excess free energy ( if has been concluded that, at a macroscopic level, these compounds form a pracfically immiscible monolayer at the air-water interface, af tt < Tlf At higher tt the collapsed protein is displaced from the interface by LMWE (monoglycerides, phospholipids, etc.). The existence of low profein interactions in disordered proteins ((3-casein and caseinate) facilitates the protein displacement by LMWE from fhe air-water interface. However, the lower surface acfivify of unsafurafed-LMWE explains the fact that this lipid has a lower capacity than saturated-LMWE for protein displacement. 

In the last few years, our research group evaluated the possibility of using monolayer techniques to caracterize caseins interactions. These techniques have allowed us to investigate the interfacial properties of milk caseins which are believed to be responsible for the interactions leading to micellar organization. Secondly, preparation of mixed films by these techniques provides relevant information about interactions between caseins and monoglycerides related to emulsion stability. 

In the small intestine, pancreozymin causes the gallbladder to contract, and bile, a micellar solution of bile acids, lecithin, and cholesterol, is secreted into the duodenum. Pancreozymin also causes discharge and continued synthesis of pancreatic lipase which adsorbs to the oil-water interface, liberating 2-monoglycerides and fatty acids (76). Whether bile acids adsorb to the interface and if so how they spatially orient with respect to lipolytic products and lipase is unknown. At concentrations below the CMC, bile acids will adsorb to monolayers of lipolytic products (77), but no information is available on the interaction of bile acid solutions above their CMC with monolayers of lipolytic products. Somehow, the lipolytic products are transferred to the bulk phase, where they form mixed micelles with bile acid molecules (Fig. 14). 

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