Influence of cereal grain non-starch polysaccharides such as beta-glucan and arabinoxylan in their native and hydrolysed forms on starch amylolysis

人类是在吃全谷物食物的背景下进化的。我们的身体被设计用来摄入和消化含有多种非淀粉多糖(NSP)(即膳食纤维的成分)、植酸盐、酚类等有益健康的淀粉谷物。然而，在现代，高度精炼的谷物配料，如白小麦粉、精米、珍珠大麦等，在食品加工中大量用作配料。这些精制成分在NSP、酚类、植酸盐等中高度消耗，并用于加工谷物食品，以改善面粉功能和促进大批量加工，以及改善食品的感官特性(例如：更软、更白的烘焙食品或更精细的质地糕点)。最近，随着社会越来越关注精制饮食对健康的负面影响，现在要求回归更有营养的全谷物食品。摆在食品行业面前的两难境地是，尽管全谷物食品中的NSP对健康有好处，但它们对大量食品加工，特别是消费者已经习惯的感官质量产生了负面影响。为了减轻NSP的这些负面影响，经常添加以微生物为基础的粗酶制剂(如木聚糖酶、β-葡聚糖酶等)，主要目的是水解NSP。这在很大程度上是一个经验性的“黑箱”过程，其中的分子细节并没有得到很好的理解。我们知道，这些粗酶通过产生水解性膳食纤维来改善食物的感官属性和加工能力。然而，NSP对人类健康的影响尚不清楚，尤其是那些部分水解的NSP如何影响淀粉分解。本研究的目的是更好地了解一些NSP的天然形式和水解形式如何影响淀粉分解。这项研究的结果预计将显示NSP将如何有益于加拿大食品业和一般公众，以智能地管理有关淀粉消化、肥胖、II型糖尿病和一般人类健康的健康问题。

Humans evolved in the context of eating whole grain foods. Our body is designed to consume and digest starchy cereal grains that contain a variety of Non Starch Polysaccharides (NSPs) (i.e. components of dietary fibre), phytates, phenolics, etc. that confer health benefits. However, in modern times, highly refined cereal ingredients such as white wheat flour, polished rice, pearled barley, etc. are used substantially in food processing as ingredients. These refined ingredients are highly depleted in NSPs, phenolics, phytates, etc and are used in processed grain foods to improve flour functionality and facilitate high volume processing, as well as to improve the food's sensory characteristics (eg: softer, whiter baked goods or finer textured pastries). More recently, as society has become more concerned about how a refined diet can affect health negatively, it now demands a return to more nutritious and whole grain foods.The dilemma presented to the food industry is that although NSPs in whole grain foods have health benefits, they negatively impact the high volume food processing and especially the sensory qualities to which consumers have grown accustomed. In order to mitigate these negative effects of NSPs, microbial based crude enzyme preparations (eg: xylanase, beta-glucanase, etc) are often added, primarily for the purpose of hydrolyzing NSPs. This is largely an empirical, "black box" process, in which the molecular details are not well understood. We know that these crude enzymes improve food sensory attributes and processing capabilities by producing hydrolyzed dietary fibre. However, the impact of NSPs on human health is not clear, especially how those partially hydrolysed NSPs affect amylolysis.The objective of the proposed research is to develop a better understanding of how some NSPs, in their native and hydrolysed form, would influence starch amylolysis. The results of this study is expected to show how NSPs would be beneficial to the Canadian food industry and the general public at large for intelligent management of health issues around starch digestion, obesity, type II diabetes, and general human health.