Terminology of Food Texture
Sensory science uses a range of subjective terminology to describe the mechanical, geometrical and chemically derived parameters that contribute to a product's textural perception by the consumer. Some terms are specifically defined as a scientifically-understood definition, whilst others are consumer nomenclature which is less consistent, but valuable to relate to the measurable attribute.
The description of food, cosmetics and pharmaceutical product texture is derived from sensory inputs from physical contact: finger feel and mouthfeel.
The following is a list of terms covering all aspects of food texture meaurement, and similar sensory-judged products, such as cosmetics and pharmaceuticals.
Accuracy – How closely the measured value comes to the true value.
Adhesiveness – Sometimes referred to as stickiness, this is related to how a food adheres to the inside of the mouth surfaces during chewing, calculated as work. Adhesive force can be measured as tension exerted on the test probe after compressing the sample. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters.
Bite Strength – A measure of the force needed for the consumer to bite through a food item. Usually correlated to the measured shear force of a texture test on that product.
Bloom – The Bloom [strength] test is an industry standard method for measuring the gelling properties of gelatine. Named after O. T. Bloom, the test sample is named from the firmness measurement in grams - e.g. 120 Bloom. The hight the Bloom value, the less geline is needed to achieve a proper set. In the process of preparing a gel for use in cooking and baking - the mixture blooms (or swells) when the powder is mixed with liquid.
Body - The sensation of substance.
Brittleness – The previous term for fracturability (see below).
Bulk – An aggregate test sample. Used when an individual item of the product is not feasible (due to small size) or representative of the way the texture is experienced (eaten as a mouthfil), or bulk analysis correlates better with the accepted production quality. Examples: whole can of vegetables, pasta, collection of animal food (kibble), set amount of fresh peas (for tenderometer analysi).
Cellular Aerated - A predominantly regular, void structure.
Chewiness – A combination of gumminess and springiness, this is the amount of effort that goes into preparing a solid product for swallowing. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the three secondary parameters. Calculated as HARDNESS x COHESIVENESS x SPRINGINESS. Mutually exclusive with gumminess and fracturability.
Coarse - Possesses large constituent particles.
Cohesiveness – Refers to how a food product stays together after deformation - a ratio of the work needed to compress a sample for a second time to the of the first. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters. In a Texture Profile Analysis (TPA), the ratio of positive area during the second to that of the first compression cycle (downward strokes only).
Consistency - General texture term usually relating to the thickness and flow of a semi-solid, correlated to cohesiveness or viscosity.
Creamy - The presence of thick, smooth liquid in the mouth.
Crystalline - The presence predominantly of a collection of crystals.
Dry - A reduction in the free fluids in the mouth.
Elasticity - The previous term for springiness (see below). Renamed due to existing terms in engineering and rheology.
Extensibility - A description describing the ability of the sample to stretch and extend elastically. A specific term relating to dough in the bakery industry - tested with the dough-gluten extensibility fixture.
Fibrous - Readily separated thread-like structure.
Fine - Small, uniform constituent particles.
Fizzy - Giving a tingling sensation, having hissing sounds, as in sparkling beverages.
Flaky - A structure of readily separated layers.
Foamed, Foamy - A predominance of small, empty or gas-filled voids in semi-solids or liquids.
Fracturability – A food’s ability to crack or crumble, the opposite of cohesiveness. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the three secondary parameters. Mutually exclusive to chewiness and gumminess This term has replaced brittleness.
Getaway - Perceived as the shortness of duration of mouthfeel.
Gritty - Presence of small, hard particles.
Gumminess – A combination of hardness and cohesiveness, this is the amount of effort that goes into preparing a semi-solid food for swallowing. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the three secondary parameters. Calculated as HARDNESS x COHESIVENESS. Mutually exclusive with chewiness and fracturability.
Hardness – The peak force that results from a sample being compressed to a given distance, time, or % of deformation, representing the firmness (or softness). One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters. In consumer (sensory) terminology, a texture with solidity and brittleness.
Juicy - A progressive increase in the free fluids in the mouth during mastication.
Lumpy - Presence of large irregular particles.
Mealy - Presence of components of different degrees of firmness or toughness. Also, grainy.
Moist - Neither an increase nor reduction in the free fluids in the oral capacity.
Mushy - The presence of wet, soft solids in the mouth.
Palatable (Palatability) - Acceptable or agreeable to the taste, mind, sensibilities (degree of acceptability, or not).
Powdery - Presence of, or readiness to breakdown into very small particles. Also, chalky.
Precision – How many significant digits are used to express the measurement.
Puffed, Puffy - An expanded and often distorted cellular structure.
Pulpy - A soft, plastic, wet, fibrous structure.
Repeatability - The variation in measurements obtained when one person measures the same unit with the same measuring equipment.
Sharp - An intense or painful reaction to a substance being eaten.
Slimy - The sensation of slipperiness on the surfaces of the mouth.
Smooth - The absence of detectable solid particles.
Soggy - Saturated with moisture, heavy and wet, sodden or soaked.
Spongy - Both stringy and cellular.
Springiness – A food’s ability to return to its original form after being compressed, measured from the deformation of the second TPA compression. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters, originally termed elasticity. Also useful to express as a ratio (see springiness index, below).
Springiness Index - Defomation of the second compression cycle divided by that of the first. A dimensionless ratio representing springiness, which more readily allows comparison between products by removing inconsistencies in size and shape of the samples.
Stringy - Presence of tough thread-like structure.
Texture – Sometimes called mouth feel, this is the physical interaction that food has in the mouth during the chewing process. This can sometimes also be interpreted by finger feel.
TPA (Texture Profile Analysis) – A two bite test that imitates the action of chewing. From the results, a number of sensory related parameters can be determined.
Viscosity - Relates to the sample's ability to flow - describing the texture of semi-solids/fluids, it is a indication of thickness. In classic rheology theory, viscosity is the resistance to deformation by shear or tensile stress, usually applied to liquids. A semi-solid product's textural properties depend upon its rheological behavior and can be tested by extrusion methods, to replicate flow, mixing, pouring or spreading actions. The texture of a sample which behaves as a fluid can be correlated to peak force and the area below a force-displacement curve. One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters. A fluid's viscosity value is measured by a viscometer (or viscosimeter) not a texture analyzer.
Watery - Both wet and deficient in body.
Waxy - The presence of thick, oily liquid or plastic solid in the mouth.
Wet - An immediate increase in the free fluids in the mouth.