We as human beings, consume a wide variety of food, each with very different mechanical properties. We drink simple liquids (like water, tea, coffee) as well as thick viscous liquids (like milkshakes or sauces). We use even more structured materials (like doughs, purees, pastes, creams) in our kitchens for baking or cooking. We also use hard solid material (like rice or noodles or pulses) for cooking our meals. We bite into the food with our teeth, crush between the tongue and palate and lubricate with saliva to form a bolus, which we can then swallow easily. This oral processing helps us understand the food texture and taste, and appreciate food in terms of its sensory quality.
With the help of processing or cooking, the raw agricultural material is converted to a wide range of cooked or processed food products with widely varied texture. Each of these foods has a unique microstructure due to very different types of interactions among its constituent building block molecules (carbohydrate, protein, lipids) and water. A fundamental knowledge of how the different molecules form structures, and how these natural or engineered structures are connected to texture perception, is essential for optimizing the food product development.
We apply all kinds of forces when we manufacture foods. During the eating process, we also apply force on foods while chewing and grinding the food in our mouth. During the oral processing of food, we do a mental calculation of the amount of force needed to break down different types of foods, thus making a subjective assessment of the texture of every food we consume. The perception of food texture is very subjective and varies widely from person to person. Therefore, we need an objective way of quantifying mechanical attributes like texture. There are still large gaps in understanding how instrumental texture measurement and human sensory texture perception can be linked.
The goal of my research is to gain a better understanding of the relationship between processes, ingredient functionalities, structures, and textural properties of foods. I am using rheology as a principal technique to reveal the mechanical response behaviour of foods. In this docent lecture, I will demonstrate how understanding the texture profile of foods can be useful in exploring product quality of soft cheese or developing alternative coating solutions in extending shelf-life of apples. Finally, I will outline how the “molecules-structure-texture” framework can be extended in future research to develop better ingredients or food products in the future.