Food texture: Concept and perception

Foods are materials and therefore have the mechanical properties of materials. Large parts of the preparation of food involve comminution, which can be related to fracture mechanics. “Texture” is governed by a combination of mechanical and fracture properties and their modification and expression within the mouth during chewing.

Texture is primarily the response of the tactile senses to physical stimuli that result from contact between some part of the body and the food. The tactile sense (touch) is the primary method for sensing texture but kinesthetics (sense of movement and position) and sometimes sight (degree of slump, rate of flow), and sound (associated with crisp, crunchy and crackly textures) are also used to evaluate texture.

The great scientist Robert Hooke, after from Hookean solids are named, explained the principle of elastic deformation of solids, and Isaac Newton, who founded the law governing the flow of simple liquids (Newtonian fluids), may be included in the founding of texture studies.

Food texture is about perception, making it above all other things a human experience. It is about people perception of a food stuff which originates in that products structure and how the product behaves when handled and eaten.

Most foods are formed from biological materials where many components are joined into complex structures. For example, bread, cakes and extruded snacks are foam structures. Man, usually manipulates these in some way to make the food easier to consume or more attractive to eat, adding another layer of structure.

People perception of food texture often constitutes a criterion by which they judge its quality and is frequently an important factor in whether they select an item or reject it.

Textural parameters of food especially fruits and vegetables are perceived with the sense of touch, either when the product is picked up by hand or placed in the mouth and chewed. In contrast to flavor attributes, these characteristics are fairly easily measured using instrumental methods. Most plant materials contain a significant amount of water and other liquid-soluble materials surrounded by a semi-permeable membrane and cell wall.

Texture can be expressed in the sounds which foods make when handled, to the extent that man can listen to foods to estimate their quality e.g. the sound of a melon when it is tapped. Familiarity with a product brings knowledge about how its texture and behavior changes during processing and storage.

Texture is assessed by subjective sensory evaluations based on psychophysics and by objective instrumental measurements based on physics and/or chemistry. Texture and related physical properties can be evaluated by instruments that measure rheology, fracture, and acoustics as well as by microscope and spectrometers, which are able to characterize the structure of materials.
Food texture: Concept and perception