Abstract

The main aim of the PhD dissertation was to indicate the importance of conjugation of bile salts (BS) on the level of lipolysis, determine factors influencing the alteration of BS composition, and establish processes controlling the rate of lipolysis. Experimental results (in-vitro digestion models, interfacial studies) and meta-analysis of literature data were combined to determine the most influential factors affecting the rate of lipolysis. The results demonstrate that several factors such as antibiotics, disease state, and gut microbiota composition may affect the lipid digestion process via the action of BS. Conjugated forms of BS - sodium taurocholate (NaTC) were shown to enhance free fatty acids (FFA) release to a significantly higher level than unconjugated forms of BS - sodium deoxycholate (NaDC) present in our gastrointestinal tract. NaTC showed greater potential to adsorb to the lipid droplet enhancing the adsorption of lipase and promoting the emulsification process. Moreover, NaTC required fewer molecules and surfactant concentration to create aggregates responsible for incorporating lipolysis products from the oil interphase. The lipolysis driven by NaTC could achieve greater FFA release due to faster removal of lipolysis products via the desorption process, allowing the continuous process of lipid digestion. The lipolysis was shown to be controlled by the concentration of conjugated BS by modulation of five identified processes.

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