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

亲水胶体(主要是可溶性多糖)是多功能食品配料。它们通过其在水相中的大分子行为，以粘性、凝胶性和胶体稳定性等属性的形式向食品提供技术功能。与此同时，这些亲水胶体作为膳食纤维，对健康有多种好处，包括增加饱腹感，餐后血糖下降，通过胆汁酸结合降低血液胆固醇水平，在结肠发酵产生短链脂肪酸，可以限制结肠内病原菌的生长，改善松弛，以及许多其他健康好处。在加拿大，我们平均只摄入推荐量的总膳食纤维(可溶和不可溶)的一半，因此在食物中补充有益纤维是一个重要和可行的健康促进策略。亲水性胶体的挑战是在不对载体食物的质地造成负面影响的同时，为每份食物提供具有营养功能的剂量的可溶性膳食纤维。本研究的目的是探索溶液中亲水胶体的结构性质(即构象、流变学)与其营养功能之间的关系；并探索将亲水胶体浓缩到食品中以实现健康益处的新方法。在体外消化每个阶段之前和之后，将在不同的模型食品基质中研究具有一系列分子结构和被证明对健康有益的亲水胶体的流变性和物理性质，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记物的影响。这项研究的预期意义将是更根本地了解结构和功能之间的关系，因此应针对哪些亲水胶体提高在食品中的利用。此外，将利用所获得的关于胃肠道提供具体健康益处的理想结构/行为的增强知识，探索将大量具有营养功能的亲水胶体纳入模型食品系统的新策略。

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.