Investigating indentation as a means of evaluating the constitutive properties of biological materials

加工食品是非常复杂的材料，在食品加工操作的各种热量、质量和动量传递事件中产生的微观结构决定了食品的性质。解开这种复杂性是准确预测新型和传统食品质量的关键，也是开发健康功能食品的成功营养负荷策略的关键。这项发现基金的研究重点是研究两种重要的食物材料，并表征它们的弹性和时间依赖性行为。计算技术将用于处理这些材料的压痕过程分析中随时间变化的行为所增加的复杂性。压痕是一种将探针插入材料表面的技术，通过测量探针位移到材料中的力来评估材料的机械性能。它是检查软材料（如食品）的脆弱结构的理想方法，因为它绕过了潜在的破坏性样品制备程序，但它可用于确定基本的机械性能。通过了解如何从压痕测试中提取基本的机械性能，该研究将使压痕成为一种简单快速的生物材料机械性能评估工具。此外，对具有网络结构的两类重要食品材料的机械行为进行系统评估，可能会发现新的物理现象，从而导致新的生物本构模型的发展。从这些模型中获得的关于如何在加工过程中优化食品质量的见解将使加工商能够制定更健康的食品，保持传统食品的质量属性，从而减少加拿大饮食相关疾病的发病率。

Processed foods are wonderfully complex materials where the microstructures created during the various heat, mass and momentum transfer events of food process operations determine the properties of the food. Unravelling this complexity is the key to accurately predicting the quality of novel and conventional foods, and to developing successful nutrient loading strategies for the creation of healthy functional foods. The research of this Discovery grant is focused on studying two important food materials and characterizing their elastic and time-dependent behaviour. Computational techniques will be used to cope with the complexity that time-dependent behaviour adds to analyses of the indentation process of these materials. [Indentation is a technique where a probe is inserted into the surface of a material and the mechanical behaviour of the material is assessed through measurement of force on the probe as it is displaced into the material. It is an ideal method for examining the fragile structures of soft materials such as foods because it circumvents potentially destructive sample preparation procedures, yet it can be used to determine fundamental mechanical properties.] By understanding how to back-extract fundamental mechanical properties from indentation tests, the research will enable indentation to be developed as a simple rapid tool for evaluations of the mechanical properties of biological materials. In addition, a systematic evaluation of the mechanical behaviour of two important classes of food materials possessing a network structure can potentially uncover novel physical phenomena, and so lead to the development of new biological constitutive models. Insights gained from these models on how food quality can be optimized during processing will allow processors to formulate healthier foods that retain the quality attributes of conventional foods, and thereby reduce the incidence of diet-related disease in Canada.