Dietary fibre enrichment in foods for targeted health benefits: relating physical and physiological properties of hydrocolloids

水胶体（主要是可溶性多糖）是多功能食品成分。它们通过其在水相中的大分子行为，以粘度、凝胶化和胶体稳定性等属性的形式为食品提供技术功能。同时，这些水胶体充当膳食纤维并提供多种健康益处，包括增加饱腹感，进食后血糖衰减，通过胆汁酸结合降低血液胆固醇水平，在结肠中发酵产生短链脂肪酸，其可以限制结肠中致病菌的生长，改善乳酸和许多其他健康益处。在加拿大，我们平均只摄入总膳食纤维（可溶性和不溶性）推荐量的一半，因此在食物中补充有益纤维是一项重要而可行的健康促进策略。水胶体的挑战是提供每份食物的营养功能剂量的可溶性膳食纤维，同时不负面地改变载体食物的质地。本研究的目的是探索水胶体在溶液中的结构性质之间的关系（即，本研究的目的是研究水胶体的形态、流变学特性及其营养功能;以及探索将水胶体富集到食品中以提供健康益处的新方法。在体外消化的每个阶段之前和之后，将在各种模型食品基质中研究具有一系列分子结构和已证实的健康益处的水胶体的流变学和物理特性，以模拟口腔，胃和肠道环境。我们还将研究它们对健康的各种生理生物标志物的影响。预期的意义是更根本地理解结构和功能之间的关系，因此应该针对哪些水胶体在食品中提高利用率。此外，将使用获得的关于胃肠道中提供特定健康益处的理想结构/行为的增强知识，探索将显著浓度的营养功能性水胶体掺入模型食物系统的新策略。

Hydrocolloids (mostly soluble polysaccharides) are multi-functional food ingredients. They deliver technological functionality to foods in the form of attributes like viscosity, gelation, and colloidal stability through their macromolecular behaviour in the aqueous phase. At the same time, these hydrocolloids act as dietary fibre and deliver a multitude of health benefits, including increased satiety, blood glucose attenuation after consumption of a meal, reduction in blood cholesterol levels through bile acid binding, fermentation in the colon to produce short-chain fatty acids, which can act to limit growth of pathogenic bacteria in the colon, improved laxation, and many other health benefits. In Canada, on average we only consume half of the recommended amount of total dietary fibre (soluble and insoluble), so supplementation of beneficial fibres into foods is an important and viable health- promoting strategy. The challenge with hydrocolloids is to provide a nutritionally- functional dose of soluble dietary fibre per food serving while not negatively altering the texture of the carrier food. The objectives of this research are to explore the relationship between the structural properties of hydrocolloids in solution (i.e., conformation, rheology) and their nutritional functionality; and, to explore novel means of enrichment of hydrocolloids into foods to deliver health benefits. The rheological and physical properties of hydrocolloids with a range of molecular structures and demonstrated health benefits will be studied in various model food matrices before and after each phase of in vitro digestion to simulate the oral, gastric and intestinal environment. We will also study their effects on various physiological biomarkers of health. The expected significance of this will be to understand more fundamentally the relationship between structure and function and therefore which hydrocolloids should be targeted for enhanced utilization in foods. In addition, novel strategies for incorporation of significant concentrations of nutritionally- functional hydrocolloids into model food systems will be explored using the enhanced knowledge gained regarding ideal stucture/ behaviour in the gastrointestinal tract that delivers specific health benefits.