How to measure and analyse the texture of food, cosmetics, pharmaceuticals and adhesives.

Tuesday, 29 August 2017

What is Food Texture and How is It Measured?

Texture refers to those qualities of a food that can be felt with the fingers, tongue, palate, or teeth. 

Foods have different textures, such as crisp crackers or potato chips, crunchy celery, hard candy, tender steaks, chewy chocolate chip cookies and sticky toffee, to name but a few.

Texture is also an index of quality. The texture of a food can change as it is stored, for various reasons. If fruits or vegetables lose water during storage, they wilt or lose their turgor pressure, and a crisp apple becomes unacceptable and leathery on the outside.

Bread can become hard and stale on storage. Products like ice cream can become gritty due to precipitation of lactose and growth of ice crystal in the freezer temperature is allowed to fluctuate, allowing thawing and refreezing.

Evaluation of texture involves measuring the response of a food when it is subjected to forces such as cutting, shearing, chewing, compressing or stretching. Food texture depends on the rheological properties of the food. Rheology is defined as the science of deformation and flow of matter or in other words, reaction of a food when a force is applied to it.

Does it flow, bend, stretch or break? 

From a sensory perspective, the texture of a food is evaluated when it is chewed. The teeth, tongue and jaw exert a force on the food, and how easily it breaks or flows in the mouth determines whether it is perceived as hard, brittle, thick, runny, and so on. The term mouthfeel is a general term used to describe the textural properties of a food as perceived in the mouth.

How a Texture Analyser works

In a simple test, the arm of the Texture Analyser containing the loadcell moves down to penetrate or compress the product, and then returns to its initial position whilst measuring forces in both directions. Texture Analysers assess textural properties by capturing force, distance and time data at high speed – data which is then displayed graphically by software.

The choice of probe or fixture that you use will depend upon the sample’s form, the property that you wish to measure or the action that you wish to perform. Fixtures are available to provide the required action of compression, extrusion, cutting, extending or bending on the sample or to support, anchor or deform the sample in a customer specific way.

Texture Analysis in Action

The main goal of many texture studies is to devise one or more mechanical tests with the capacity to replace human sensory evaluation as a tool to assess texture. Measurements that yield both fundamental and empirical product characteristics are well developed, whilst wide-ranging imitative test procedures are also becoming increasingly important.  Their relevance is in imitating a real-life situation, which permits far simpler data interpretation.

Texture analysis imitative tests
Many Texture Analysers tests, such as the Bloom Strength test for gelatin gels, are International Standards, whereas others are recognised as standard tests within an industry, such as Texture Profile Analysis for many food products.

To be successful, all of these tests depend upon the integrity of the Texture Analyser and the selection of the correct testing method, the manufacturing precision of the probe or attachment used and the accuracy of the analytical software to provide the results in a clear, concise format.

The TA.XTplus Texture Analyser with its wealth of application methods and the range of over 200 probes and attachments are the result of decades of experience in the design and manufacture of this equipment. Stable Micro Systems offers the most universal Texture Analysers available today – the TA.XTplus and TA.HDplus ‘World Standard’ instruments – to completely satisfy the increasing demands for accurate, repeatable and quantifiable textural information.

For more information on how to measure texture, please visit the Texture Analysis Properties section on our website.

TA.XTplus texture analyser with bloom jar The
TA.XTplus texture analyser is part of a family of texture analysis instruments and equipment from Stable Micro Systems. An extensive portfolio of specialist attachments is available to measure and analyse the textural properties of a huge range of food products. Our technical experts can also custom design instrument fixtures according to individual specifications.

No-one understands texture analysis like we do!

To discuss your specific test requirements, click here...

Watch our video about texture analysis Replicating Consumer Preferences Texture Analysis applications

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