Measurement of micro-rheological properties of food structures

食品结构微观流变特性的测量

• 批准号: 344501-2007
• 负责人: Dalgleish, Douglas
• 金额: $ 1.33万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=325555
• 关键词: Measurement; micro; rheological; properties; food

A great many foods are made up of small (colloidal) particles.  Some are simply dispersions of particles (milks, creams, mayonnaises, cream liqueurs) that have to be kept in a stable condition until they are consumed.  On the other hand, some foods are created by causing their constituent particles to become unstable, so that they form curds or gels or other structures that provide acceptable textures for the consumer.  Well-known examples of these are cheese, yogurts, and ice cream.  The control of stability (or instability) of the basic particles in these products is clearly of considerable importance.  The particles are also of importance in the nanoengineering of foods, and can be used to carry important food ingredients such as flavours or nutritionally important molecules that must be protected from breakdown (such as by oxidation). The question we are trying to answer is: how is the stability of different types of particles maintained and how can it be controlled?  Especially, we are interested in how particles like the casein micelles of milk can be controllably destabilized to give defined curd structures.  One of the newest methods of studying this is the technique of Diffusing Wave Spectroscopy (DWS), which allows us to use the light scattered from a colloidal suspension to tell us about the way in which the particles interact.  Using the equipment we can look at the earliest stages of gel formation and at the interactions between the particles.  The technique also has the possibility of measuring the strengths of the very weak gels that are formed in these early stages.  It is at this stage that it may be possible to intervene to control the properties of the subsequent gel.  If we can understand what is happening at these early stages, we may be able to exercise a hitherto impossible control over the structures and properties of the final foods.  It is for this reason that we wish to improve the instrumentation we have, so that we can measure these very weak gels and learn even more about the mechanisms and control of gelation reactions in foods.

很多食物都是由细小的(胶体)颗粒组成的。有些只是颗粒(牛奶、奶油、蛋黄酱、奶油利口酒)的分散，在食用前必须保持稳定状态。另一方面，一些食物是通过使其组成颗粒变得不稳定而产生的，从而形成凝乳、凝胶或其他结构，为消费者提供可接受的质地。众所周知的这些例子有奶酪、酸奶、控制这些产品中基本颗粒的稳定性(或不稳定性)显然是相当重要的。这些颗粒在食品的纳米工程中也很重要，可以用来携带重要的食品配料，如香料或必须防止分解(如通过氧化)的营养重要分子。我们试图回答的问题是：如何保持不同类型颗粒的稳定性，以及如何控制它？尤其是，我们感兴趣的是如何可控地使牛奶中的酪蛋白胶束等颗粒失稳，以获得明确的凝乳结构。研究这一问题的最新方法之一是扩散波光谱(DWS)技术，这使得我们可以使用从胶体悬浮液中散射的光来告诉我们粒子相互作用的方式。使用该设备，我们可以观察凝胶形成的最早阶段以及粒子之间的相互作用。这项技术还有可能测量在这些早期阶段形成的非常弱的凝胶的强度。正是在这个阶段，才有可能进行干预，以控制随后的凝胶的性质。如果我们能够理解在这些早期阶段发生的事情，我们也许能够对最终食品的结构和性质进行迄今不可能的控制。正是出于这个原因，我们希望改进我们拥有的仪器，以便我们能够测量这些非常弱的凝胶，并更多地了解食品中凝胶反应的机制和控制。