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The Influence of Surfactants on Lipase Fat Digestion in a Model Gastro Intestinal System

Pedro Reis (Institutionen för kemi- och bioteknik, Teknisk ytkemi) ; Thomas Raab ; J-Y Chuat ; Martin Leser ; Reinhard Miller ; Heribert Watzke ; Krister Holmberg (Institutionen för kemi- och bioteknik, Teknisk ytkemi)
Food Biophysics (1557-1858). Vol. 3 (2008), 4, p. 370-381.
[Artikel, refereegranskad vetenskaplig]

In the present study, we use a model gastro-intestinal system to study the influence of different food-grade surface-active molecules (Sn-2 monopalmitin, beta-lactoglobulin, or lysophosphatodylcholine) on lipase activity. The interfacial activity of lipase and surfactants are assessed with the pendant drop technique, a commonly used tensiometry instrument. A mathematical model is adopted which enables quantitative determination of the composition of the water-oil interface as a function of bulk surfactant concentration in the water-oil mixtures. Our results show a decrease in gastric lipolysis when interfacially active molecules are incorporated into a food matrix. However, only the Sn-2 monopalmitin caused a systematic decrease in triglyceride hydrolysis throughout the gastro-intestinal tract. This effect is most likely due to exclusion of both lipase and triglyceride from the water-oil interface together with a probable saturation of the solubilization capacity of bile with monoglycerides. Addition of beta-lactoglobulin or lysophopholipids increased the hydrolysis of fat after the gastric phase. These results can be attributed to an increasing interfacial area with lipase and substrate present at the interface. Otherwise, beta-lactoglobulin, or lysophopholipids reduced fat hydrolysis in the stomach. From the mathematical modeling of the interface composition, we can conclude that Sn-2 monopalmitin can desorb lipase from the interface, which, together with exclusion of substrate from the interface, explains the gradually decreased triglyceride hydrolysis that occurs during the digestion. Our results provide a biophysics approach on lipolysis that can bring new insights into the problem of fat uptake.

Nyckelord: Lipase, Fat, Hydrolysis, Emulsion, Digestion, Surfactant, Model gastro-intestinal system, TNO intestinal model



Denna post skapades 2008-12-10. Senast ändrad 2013-01-23.
CPL Pubid: 80876

 

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Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Teknisk ytkemi (2005-2014)

Ämnesområden

Kemi
Kemiteknik
Kemi

Chalmers infrastruktur