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There is a lack of effective delivery systems to encapsulate, protect and release bioactive lipid components (e.g., w-3 fatty acids, carotenoids and phytosterols), which is holding back the development of functional foods that combat diseases such as coronary heart disease, diabetes and cancer. Delivery systems consisting of lipid droplets encapsulated by nano-laminated biopolymer coatings have great potential for use in the food industry, but there is some concern about the bioavailability of the encapsulated lipids. The objective of this project is to address this problem by establishing the relationship between the physicochemical characteristics of nano-laminated biopolymer coatings and the bioavailability of encapsulated lipids. In vitro studies, using a simulated gastrointestinal tract, should provide fundamental mechanistic insights into the impact of specific coating properties (e.g., composition, thickness, charge) on lipid digestibility. In vivo studies, using a rat feeding model, would be used to test the bioavailability of lipids encapsulated within specifically designed coatings. This study would lead to the creation of delivery systems with controllable lipid bioavailability, e.g., fully digestible, fully indigestible, or targeted release systems.
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The specific goals that will be carried out to achieve the overall objective are listed below: <OL> <LI> We will determine the role of nano-laminated coating properties on the in vitro digestibility/release of lipids. <LI> We will determine the role of the composition and structure of nano-laminated coatings on the bioavailability of encapsulated lipids using animal feeding studies.
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The expected outputs from the project are listed below: <BR> <BR>Activities: We will conduct and analyze scientific experiments that will generate important new fundamental and practical insights, as well as training scientists (graduate students and Post-Docs). <BR><BR>Services: The knowledge gained from this project will be useful for the food industry for designing and fabricating novel delivery systems for functional food components, and will be imparted through scientific presentations and consulting. <BR><BR>Products: New fundamental and applied knowledge will be generated through this project about the formation of innovative delivery systems for bioactive lipids. It is possible that some of this work could lead to patent applications and/or license agreements. In addition, the project will lead to the training and graduation of new students and scientists that have important skills necessary for the modern food industry. <BR><BR>Dissemination: The results of the project will be presented at scientific meetings, meetings with industry, and in peer-reviewed scientific publications.
NON-TECHNICAL SUMMARY: This proposed research would generate structural design principles that could be used by the food industry to create nano-laminated coatings with controllable digestibility, e.g., fully digestible, fully indigestible or controlled digestibility. Fully digestible coatings could be utilized in high performance delivery systems that encapsulate and protect bioactive lipids (such as č-3 fatty acids, carotenoids and phytosterols) during storage, without adversely affecting their bioavailability. Fully indigestible coatings could be used to create innovative reduced-calorie foods, by making some or all of the lipid phase indigestible. Coatings with controllable digestibility could be used in targeted delivery systems designed to deliver bioactive components (or hydrophobic drugs) to specific locations within the GI tract, e.g., mouth, stomach, small intestine, large intestine or colon. The increased consumption of bioactive lipids could have major health and economic benefits on the nation, by reducing the incidences of diseases such as obesity, coronary heart disease, diabetes and cancer. This project would build upon our previous work demonstrating the great potential of nano-laminated coatings at improving the stability and performance of emulsified lipids. In addition, it would form the platform for future research, e.g., development of nano-laminated coatings to encapsulate, protect and deliver other food components (e.g., flavors) and non-food components (e.g., drugs). Ultimately, it will be important to test the efficacy of nano-laminated coatings in real food systems using human feeding studies.
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APPROACH: The following scientific methods and protocols will be used to successfully conduct the project: (1). General Methods Suitable biopolymers (proteins and dietary fibers) will be selected based on their molecular characteristics and characterized using electrophoresis, light scattering, and viscosity measurements. Lipid droplets with controllable properties will be prepared by high pressure homogenization, and their properties will be characterized by electrophoresis, light scattering, and microscopy. Nanolaminated lipid droplets will be prepared by mixing charged lipid droplets with oppositely charged biopolymer solutions under conditions where the biopolymers adsorb to the lipid droplet surfaces but do not promote aggregation. The number of layers, sequence of layers, biopolymer types, pH and salt concentration will be varied in systematic fashion and its effect on layer properties determined. The charge, size and structure of the resulting nano-laminated lipid droplets will be characterized by electrophoresis, light scattering, and microscopy. The digestibility of the encapsulated lipids will be studied using in vitro and in vivo digestion models. All experiments will be preformed on triplicate samples and repeated at least two times. The general linear model procedure will be used to test for significance and the Duncan's multiple range test will be used to determine significance between means. (2). Experimental Protocol The following studies will be carried out: (A). The optimum composition and preparation methods for fabricating nano-laminated lipid droplets with different coating properties will be established. (B). The impact of biopolymer type, number of layers, environmental conditions (pH, salt) and cross-linking on the properties of the nanolaminated coatings will be established. (C). The influence of specific coating properties on the digestibility of encapsulated lipids will be established using an in vitro digestion model. (D). The influence of specific coating properties on the digestibility of encapsulated lipids will be established using an in vivo animal feeding study. These experiments will generate fundamental knowledge that could be used by the food industry to rationally design effective delivery systems for functional lipids. Efforts will be made to disseminate the knowledge to the food industry through