title: Real-time measurements to characterize dynamics of emulsion interface during simulated intestinal digestion.
abstract: Efficient delivery of bioactives remains a critical challenge due to their limited bioavailability and solubility. While many encapsulation systems are designed to modulate the digestion and release of bioactives within the human gastrointestinal tract, there is limited understanding of how engineered structures influence the delivery of bioactives. The objective of this study was to develop a real-time quantitative method to measure structural changes in emulsion interface during simulated intestinal digestion and to correlate these changes with the release of free fatty acids (FFAs). Fluorescence resonant energy transfer (FRET) was used for rapid in-situ measurement of the structural changes in emulsion interface during simulated intestinal digestion. By using FRET, changes in the intermolecular spacing between the two different fluorescent probes labeled emulsifier were characterized. Changes in FRET measurements were compared with the release of FFAs. The results showed that bile salts and pancreatic lipase interacted immediately with the emulsion droplets and disrupted the emulsion interface as evidenced by reduction in FRET efficacy compared to the control. Similarly, a significant amount of FFAs was released during digestion. Moreover, addition of a second layer of polymers at emulsion interface decreased the extent of interface disruption by bile salts and pancreatic lipase and impacted the amount or rate of FFA release during digestion. These results were consistent with the lower donor/acceptor ratio of the labeled probes from the FRET result. Overall, this study provides a novel approach to analyze the dynamics of emulsion interface during digestion and their relationship with the release of FFAs.
authors: Department of Food Science and Technology, University of California-Davis, Davis, CA 95616, United States.
authors: Yuanjie
authors: Y
authors: Pan
authors: Department of Food Science and Technology, University of California-Davis, Davis, CA 95616, United States; Department of Biological and Agricultural Engineering, University of California-Davis, Davis, CA 95616, United States. Electronic address: nnitin@ucdavis.edu.
authors: N
authors: N
authors: Nitin
mesh_terms: D001647:Bile Acids and Salts / Q000378:metabolism; D001682:Biological Availability; D004063:Digestion; D065546:Drug Liberation; D004655:Emulsions / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics*; D005230:Fatty Acids, Nonesterified / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007700:Kinetics; D008049:Lipase / Q000378:metabolism; D013499:Surface Properties
chemical_list: D001647:Bile Acids and Salts; D004655:Emulsions; D005230:Fatty Acids, Nonesterified; D005456:Fluorescent Dyes; D008049:Lipase; C518354:PNLIP protein, human
keywords: Dynamics of emulsion interface; Fluorescence resonance energy transfer (FRET); Simulated intestinal digestion