Food rheologyis the study of therheologicalproperties of food, that is, the consistency and flow of food under tightly specified conditions.[1]The consistency, degree of fluidity, and other mechanical properties are important in understanding how long food can be stored, how stable it will remain, and in determining food texture. The acceptability of food products to the consumer is often determined by food texture, such as how spreadable and creamy a food product is. Food rheology is important inquality controlduring food manufacture and processing.[2]Food rheology terms have been noted since ancient times. In ancientEgyptbakers judged the consistency of dough by rolling it in their hands.[3]
There is a large body of literature on food rheology because the study of food rheology entails unique factors beyond an understanding of the basic rheological dynamics of the flow and deformation of matter. Food can be classified according to its rheological state, such as asolid,gel,liquid,emulsionwith associated rheological behaviors, and its rheological properties can be measured.[4]These properties will affect the design offood processingplants, as well asshelf lifeand other important factors, including sensory properties that appeal to consumers. Because foods are structurally complex, often a mixture of fluid and solids with varying properties within a single mass, the study of food rheology is more complicated than study in fields such as the rheology ofpolymers.[5]
The most important factor in food rheology isconsumerperception of the product. This perception is affected by how the food looks on the plate as well as how it feels in the mouth, or "mouthfeel". Mouthfeel is influenced by how food moves or flows once it is in a person's mouth and determines how desirable the food is seen to be.[1]
An understanding of the rheological properties of food and drink products and their ingredients is vital for those involved with product development and processing. Furthermore, the rheological properties of the final end-products are fundamental in influencing various quality attributes, such as shelf-life stability, mouthfeel and texture, as well as consumer acceptance/appeal.
Rheology and texture measurements are carried out every day in laboratories, product development kitchens and factories. A wide range of equipment, such as viscometers, rheometers and texture analysers, are utilised to produce rheological data, which is interpreted and correlated to the performance of ingredients, mid-products and end-products.