Have you ever wondered why you like to eat some foods more than others? What makes you choose one particular brand of chocolate bar, despite the fact that they all look similar? Consumer surveys revealed that taste is the most powerful determinant of our food choices, leaving behind product price or nutritional value. This is the reason why many healthier food options lose competition to their original versions.
Scientists and big food companies continuously work to expand understanding of the science behind ‘taste’. There is evidence supporting the hypothesis that we are born with certain eating preferences which might be inherited from our ancestor’s art of survival. Approximately half of the population is craving for sweetness which is an energy-dense food indicator as well as a stimulator of the reward system in our brain. In comparison bitterness indicates toxicity and should prevent us from eating spoiled or toxic food. However, ‘taste’ is much more than only sweetness or bitterness.
Texture is another component which plays a key role in product acceptance. The Organisation of International Standards describes texture as: ‘all the mechanical, geometrical and surface attributes of the product perceptible using mechanical, tactile, visual and auditory receptors’. Texture is directly related to food structure, in other words to composition, type and proportion of proteins, carbohydrates, fats and water.
Researchers try to bridge the gap between food structure and product properties. For example it was discovered that fat is a great contributor to the experience of food consumption as it is a carrier of aroma and flavour. It also impacts on palatability, creaminess, crispness and flakiness of the food product. Discrete particles of fat act as filler and contribute to the sensation of thickness and perception of smoothness which significantly influence food texture and mouthfeel (perception of texture during consumption).
Latest research suggests that our preference towards fatty foods could be related to fat-specific receptors. Scientists discovered receptor that responds to linoleic acid, found in natural fats such as sunflower oil, soya oil or corn oil.
Sensory studies also revealed that a direct relationship exists between size of the particles in the food microstructure and texture perception. Particle sizes below 0.1 micrometers resulted in a watery sensation and sizes between 0.1-3 micrometers were related to the sensation of creaminess, while particles above 3 micrometers provided a gritty sensation.
Research carried out by Richardson has indicated that thickness perception can be related to the product viscosity which can be characterised by food rheology. This is a helpful technique especially in product reformulation to compare rheological properties of various samples and match closely desired application. It can be also used to mimic initial stages of the eating process (first bites) to observe the impact on food structure deformation. Further food structure processing in the mouth can be mimicked using food tribology.
Tribology investigates what happens with the food structure between the saliva-lubricated tongue and palate and how it deforms or breaks down during eating. Thanks to Dr. Alina Surmacka Szczesniak and her Texturometer we are able to evaluate and tailor food texture parameters such as: hardness, cohesiveness, adhesiveness, viscosity, brittleness, chewiness, and gumminess. Those are just a few examples of what we know about food structure. With more research we will better understand the relationship between food structure and consumer acceptance and we will be able to reformulate existing and develop new, healthy and tasty foods.
About the Author
Izabela Gładkowska-Balewicz is a Research Associate on the Innovate UK project at the University of Leicester which aims to revolutionize the way the food is produced. Her PhD research project was undertaken at the University of Birmingham in the School of Chemical Engineering. The main research interest of the project was the design and development of novel hydrocolloid structures which would enable product reformulation and fat reduction in soft solid foods without compromise on taste and texture.