Effects of emulsifier charge and concentration on pancreatic lipolysis: 2. Interplay of emulsifiers and biles

Research output: Contribution to journalArticle

Authors

  • Zahari Vinarov
  • Slavka Tcholakova
  • Borislava Damyanova
  • Yasen Atanasov
  • Nikolai D. Denkov
  • Simeon D. Stoyanov
  • Alex Lips

Colleges, School and Institutes

External organisations

  • Sofia University St. Kliment Ohridski
  • Unilever Research and Development
  • Unilever

Abstract

As a direct continuation of the first part of our in vitro study (Vinarov et al., Langmuir2012, 28, 8127), here we investigate the effects of emulsifier type and concentration on the degree of triglyceride lipolysis, in the presence of bile salts. Three types of surfactants are tested as emulsifiers: anionic, nonionic, and cationic. For all systems, we observe three regions in the dependence degree of fat lipolysis, α, versus emulsifier-to-bile ratio, fs: α is around 0.5 in Region 1 (fs < 0.02); α passes through a maximum close to 1 in Region 2 (0.02 < fs < fTR); α is around zero in Region 3 (fs > fTR). The threshold ratio for complete inhibition of lipolysis, fTR, is around 0.4 for the nonionic, 1.5 for the cationic, and 7.5 for the anionic surfactants. Measurements of interfacial tensions and optical observations revealed the following: In Region 1, the emulsifier molecules are solubilized in the bile micelles, and the adsorption layer is dominated by bile molecules. In Region 2, mixed surfactant-bile micelles are formed, with high solubilization capacity for the products of triglyceride lipolysis; rapid solubilization of these products leads to complete lipolysis. In Region 3, the emulsifier molecules prevail in the adsorption layer and completely block the lipolysis.

Details

Original languageEnglish
Pages (from-to)12140-12150
Number of pages11
JournalLangmuir
Volume28
Issue number33
Publication statusPublished - 21 Aug 2012