Elevated levels of lipids and LDL-cholesterol in the blood are significant risk factors associated with developing cardiovascular diseases (CVDs). A potential strategy to combat these risk factors is decreasing lipid absorption by modulating the digestibility of lipids in the human intestinal tract. Since bile salts (BS) play key roles during this process, lipid digestion could be controlled ultimately by limiting the access of BS to the lipid surface. Cellulose ethers (CEs), surface-active dietary fibers and common food additives, might be promising ingredients to control lipid digestion either by creating surface layers around lipid droplets that hinder adsorption of BS, or by sequestering BS in the aqueous phase. However, the precise mechanisms behind these interactions remain unclear. Surface analysis techniques were used to better understand the mechanisms by which CEs with diverse molecular structure and charge (commercial and novel hydroxypropyl-cellulose (HPC)) interact with BS at the solid surface and in the aqueous phase. The potential of CE-stabilized emulsions to influence lipid digestion was also investigated in vitro. Both CEs show potential in modulating lipid digestion; the potential of the commercial HPC to interfere with lipid digestion may be more related to its ability to sequester BS in solution and form mixed HPC-BS complexes that are not easily removed from the surface, whereas the novel HPC seems more effective at creating strong surface layers that resist displacement by BS. These findings can be exploited in developing strategies to design novel food matrices with improved functional properties to optimize lipid digestion and absorption. / MSLFS / Diseases of the heart and circulation are the number one cause of death in the United States (US) and it is predicted that at least 45% of the US population (131.2 million) will have some form of these diseases by 2035. Consumption of reduced-fat foods is one strategy to combat CVDs, but fats contribute to various sensory and nutritional properties of foods. Another strategy is to develop foods that incorporate dietary fibers which could interfere with the digestion of fat. However, the mechanism behind the ability of dietary fiber to interfere with fat digestion remains unclear and depends on the fiber type. One of our objectives was to look at the main interactions between a type of dietary fiber, cellulose derivatives (which are ingredients used in the food industry), and two types of bile salts, (BSs) which are important intestinal components present during fat digestion, at a surface representing a fat droplet and in the aqueous phase. Another objective was to look at the digestibility of cellulose derivative systems, compared to another food ingredient (Tween 20). We found that the different BSs played different roles at the surface and interacted differently with the cellulose derivatives. We also found that both cellulose derivatives showed potential in interfering with lipid digestion. This allows a better understanding of how cellulose derivative systems are affected by digestion and could allow us to design new foods with natural products from plants to improve wellness in the US.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/99285 |
| Date | 14 January 2019 |
| Creators | Zornjak, Jennifer Anne |
| Contributors | Food Science and Technology, Fernandez-Fraguas, Cristina, Edgar, Kevin J., Neilson, Andrew P., Esker, Alan R. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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