Influence of dietary lipid physical properties and supramolecular structure on digestibility and nutritional functionality

膳食脂质物理性质和超分子结构对消化率和营养功能的影响

• 批准号: RGPIN-2019-05012
• 负责人: Wright, Amanda
• 金额: $ 3.42万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715324
• 关键词: Influence; dietary; lipid; physical; properties

Food properties are important determinants of their biological fate, including their ability to be digested in the gastrointestinal (GI) tract. For lipids to be absorbed, they must first be solubilized (i.e. made bioaccessible) through complex emulsifying, hydrolyzing and solubilizing processes. There is extensive knowledge about how lipid structure and physical properties (e.g. melting temperature, solid fat content, crystal morphology, distribution within droplets) influence functionality in foods. However, our understanding of how to optimize these parameters to tailor bioavailability and metabolic response is in its relative infancy. For example, what role does triacylglycerol (TAG) polymorphism play in digestive lipolysis? Does the amount and arrangement of crystallinity in an emulsion droplet alter the release of encapsulated lipids or constituent fatty acids? Can TAG crystallinity be engineered to alter colloidal behaviour, and hence gastric emptying, lipemic response and satiety? This proposal aims to address these questions through the application of basic physicochemical analyses, in vitro digestion methods and human research tools. It supports the long-term goal of understanding the relationships between food physicochemical properties and metabolic response. This research targets a better understanding of the physical basis of lipid digestion. It specifically aims to determine the role of TAG supramolecular (vs. molecular) structure and physical properties in GI processes. Emulsions will be produced containing different solid fat contents and crystalline properties (e.g. size, shape, polymorph, location in droplets), using tempering, shear, and emulsifier-lipid combinations. They will be exposed to conditions representative of the upper GI tract using static or dynamic digestion models, with sampling to study lipolysis, bioaccessibility and changes in colloidal and physical state. Experiments with tempered trimyristin droplets will address the hypothesis that interfacial lipolysis is faster for lipids in relatively less dense polymorphic forms. In vitro digestion methods and biochemical and biophysical techniques will also be coupled to investigate the processes of encapsulated lipid and fatty acid solubilization, in relation to TAG melting temperature and crystallinity. Lastly, because digesta microstructure can be influenced by lipid crystallinity and physical properties, and in turn impact gastric processing, human studies of gastric emptying by ultrasound, lipemia, and satiety ratings will be incorporated to examine emulsions structured with crystalline TAG. In summary, there are significant knowledge gaps about the physical basis of digestion that preclude a sufficient understanding of how lipids contribute to metabolic function. By focusing on the role of TAG physical properties, this work will generate novel insights to support the development of evidence-based food products and dietary recommendations for lipids.

食物特性是决定其生物命运的重要因素，包括它们在胃肠道中被消化的能力。为了使脂质被吸收，它们必须首先通过复杂的乳化、水解和增溶过程被增溶（即使生物可及）。关于脂质结构和物理性质（如熔化温度、固体脂肪含量、晶体形态、液滴内分布）如何影响食品中的功能，人们已经有了广泛的了解。然而，我们对如何优化这些参数来定制生物利用度和代谢反应的理解还处于相对初级阶段。例如，三酰基甘油（TAG）多态性在消化脂肪分解中起什么作用？乳剂液滴中结晶度的数量和排列是否会改变被包裹的脂质或组成脂肪酸的释放？TAG的结晶度是否可以改变胶体行为，从而改变胃排空、血脂反应和饱腹感？本提案旨在通过应用基本的理化分析、体外消化方法和人体研究工具来解决这些问题。它支持理解食物理化性质和代谢反应之间关系的长期目标。