How "chewing things over" can help analyse semi-solid produce

Jo Smewing reports on improving quality in the dairy industry through the use of sophisticated analysis equipment, concentrating on a new machine designed to measure the structural breakdown of semi-solid produce.

Today's dairy industry is marked by tightening quality standards and a greater emphasis on innovative product development. The need for improvements to quality standards has been reinforced by wider issues, such as BSE, foot-and-mouth disease and attitudes to GM foods, which have had a negative impact on consumer confidence and the dairy industry as a whole.

The effect on sales of British foods abroad, including dairy products such as cheese, is long-lasting and UK food manufacturers are still fighting to regain ground from foreign competition which quickly filled the gap in their absence. Furthermore, as consumer tastes become increasingly sophisticated, supermarkets are displaying a wider variety of dairy products in attempt to supply consumers with the choice they desire.

One way UK manufacturers can survive in this competitive environment and regain consumer satisfaction and market share, is to invest in the quality of their products as well as new product development and innovation. According to a recent report, "the secret is not to see quality as a compliance issue, but as an integral part of the whole manufacturing process.“

Texture analysis is a key element in the production of high quality goods. Recent surveys have demonstrated that product texture is closely linked to its popularity. The softness or hardness of a cheese, for example, can have a lasting influence on brand loyalty, and the work softening of baking fats can effect the texture and quality of the finished product. By conducting thorough and effective tests using sophisticated analysis equipment, dairy producers can meet the requirements of modern consumers.

Until recently, manufacturers have tended to use more traditional, manual methods of texture analysis. These are now giving way to multi-purpose instruments, such as Stable Micro Systems' TA.XT2i texture analyser, which provide highly accurate and objective results. Sophisticated analysis equipment can provide a fuller and more accurate profile of the textural properties of a product, so manufacturers can supply goods which closely match consumer requirements. Using different attachments, manufacturers can analyse textural properties such as the work softening of fats and hardness of cheese or ice cream.

An important textural property analysed by manufacturers is structural breakdown. This occurs during production processes ­ such as blending and mixing of ingredients ­ or during mastication, and can greatly affect the quality of the finished product. Until now, the dairy industry has lacked the technology to mimic this structural breakdown realistically. Machines have been non-continuous ­ restricted to one or two compressions ­ and often prone to slipping or sticking. Stable Micro Systems', the Multiple Extrusion Cell, provides a continuous, accurate and realistic way of assessing the breakdown of some major dairy products.

The innovative design of the Multiple Extrusion Cell renders it an efficient and highly accurate means of testing structural breakdown. It comprises of an outer vessel and an inner cylinder, in which the sample product is placed. These fit inside each other and are attached to the base of Stable Micro Systems' TA.XT2i, TA.XTPlus, or TA.HDi texture analyser. A flat-based piston with circular holes, inserted through the core of this cylinder, manipulates the sample product. To ensure the tests operate under a constant temperature, deep spiral grooves on the internal surface of the outer jacket allow water to be circulated evenly over the inner vessel wall. Plugs and aO' rings are fitted accordingly to prevent water loss and leakage of the sample.

The distance, force, speed and duration of the tests can be decided by the user. Software collects and analyses the data, producing spreadsheets and/or graphs which depict the rate and extent of the breakdown. The change in consistency of semi-solid foods during chewing can, therefore, be measured accurately and analysed effectively.

There are extensive advantages to using the Multiple Extrusion Cell in the dairy industry as, ultimately, it helps to achieve greater consumer satisfaction. Frustration, for instance, is sometimes experienced when a cheese or an ice cream leaves an unsatisfactory mouthfeel or has an especially long chew rate. This could be eliminated through adequate testing of the product beforehand. In addition, where high force and/or excessive time is needed to break the product down, manufacturers may choose to alter the recipe or production process.

Performance and quality can be pre-tested with greater accuracy, ensuring the finished product meets customer satisfaction and avoiding costly mistakes.

Butter and fats

Worksoftening of bakery fats occurs in several bakery processes and can greatly affect the texture and quality of the finished product; fats are worked intensively until their crystal networks are gradually broken down to create thin sheets. Worksoftening is crucial in the processing stage of laminated doughs, such as puff pastry, for example. Some fats worksoften much quicker than others, which can cause problems in the lamination of pastry. Roll-in fats must maintain their firmness through proofing, until the pastry is baked, so that the flaky texture of puff pastry can be achieved. Using the Multiple Extrusion Cell to test the rate and extent of worksoftening, manufacturers can pinpoint potential problems at an early stage in product development, resulting in a butter or margarine with a breakdown rate that is fully suited to its area of application and processing temperature.


It is widely recognised that cheese is one of the international dairy industry's long-term growth sectors. The market is continuing to expand, driven in particular by new product development, market segmentation, and increased efforts to brand what has primarily been a commodity product. Recent years have also shown a significant growth in sales of premium products and a growing interest in speciality and imported cheeses such as Asiago and Gorgonzola.

Supermarkets are stocking more innovative products such as cheese and cracker selections, cheese dippers and more original sandwiches filled with a selection of less well-known cheeses. With increased competition, manufacturers need to concentrate on improving their products or creating new ones.

Effective pre-testing of cheeses helps to improve the quality of the finished product. Using the Multiple Extrusion Cell, manufacturers can test the structural breakdown of a wide variety of cheeses under controlled temperatures; this is especially important for soft cheeses such as brie or camembert. The production process or the ingredients used to make the cheese can then be manipulated to optimise its breakdown rate. The Multiple Extrusion Cell can test with different settings for different products, so it will help to differentiate between the vast array of textures in today's cheese market.

Ice cream

Recent developments in the global ice cream market have demonstrated an emphasis on new product development. With confectionery giants such as Mars and Nestlé extending their brands in the impulse ice cream market, pressure has been placed on other producers to create more innovative ice creams. Manufacturers are, therefore, searching for new methods of differentiation through improvement or extension of product ranges.

Thorough texture analysis can help ice cream manufacturers improve the quality and appeal of their products. Part of the attraction of an ice cream is the speed at which it melts and breaks down in the mouth. The appeal of certain ice cream types is found in their viscosity, creaminess, or long-lasting mouthfeel, so a slow breakdown rate is desirable.

The pleasure of sorbets, on the other hand, is often found in the speed at which they break down and dissolve in the mouth.

Given the diverse textural requirements of ice creams, the Multiple Extrusion Cell can be used to test, analyse and help provide a unique point of difference for individual brands. Its constant temperature control facility also enables it to closely mimic the temperature acting on the ice cream in the mouth during mastication.

Consequently, the Multiple Extrusion Cell allows manufacturers to achieve more realistic results than many other test methods.

Jo Smewing is applications manager at Stable Micro Systems, Godalming, Surrey, UK.

Recent Issues