Texture Analysis in action: the Kieffer Dough and Gluten Extensibility Rig

The KIEFFER DOUGH & GLUTEN EXTENSIBILITY RIG (A/KIE) was invented by Dr. Kieffer at the Kurt-Hess Institute, Munich, as an improved method for the accurate determination of dough and gluten extensibility.

Parallel tests of dough and gluten can reveal particular characteristics arising from homogenisation, long relaxation times or from adding oxidants, salts, emulsifiers or enzymes.

It’s time to perform Textural Magic! Part One

An introduction to Culinology, Texture and Molecular Gastronomy

Molecular gastronomy, originally a term coined to describe the scientific study of food and cooking, is now more associated with innovative modern cuisine.

Successful chefs have realised that to be at the top of their game they need to create new culinary experiences using a combination of unusual tastes, textures and theatrical twists to give the eating experience a new multi-sensory dimension. This is enabled by a variety of new high-tech equipment, adjusted traditional preparation techniques and a handful of clever chemicals.

Whilst molecular gastronomy has been the application of scientific principles to the understanding and improvement of small scale food preparation, a recent explosion in food technology and the demand for gourmet, nutritious and unique sensory experiences has created a new career opportunity called Culinology. This blends the training of a culinary arts chef with food science and nutrition education to form an exciting new highly desirable career path.

Texture Analysis in action: Universal Syringe Rig

The innovative UNIVERSAL SYRINGE RIG* (A/USR) effectively measures the aspiration and extraction forces of syringe pistons.

The extraction force quantifies how easily the injectable material is expressed during syringe depression and material discharge. This measured force impacts patient comfort during injection and affects how the material is received when deposited under the skin.

Let's get cracking - tips and tricks for successful fracturability testing

FRACTURABILITY is the tendency of a material to fracture, crumble, crack, shatter or fail upon the application of a relatively small amount of force or impact.

It is usually displayed by a product of high degree of hardness and low degree of cohesiveness and is commonly the textural property possessed by baked goods, snacks and generally 'dry' products. 

Fracturability encompasses crumbliness, crispiness, crunchiness and brittleness. A material is brittle if it is liable to fracture when subjected to stress. That is, it has little tendency to deform (or strain) before fracture and usually makes a snapping sound.

Assessing single point fracture

Sometimes you quite simply want to measure the force to break something in the middle.  Many products exist in a solid bar form and as such their snap strength – or force to break – is of interest.

A Three Point Bend test mimics the breaking of the product in half by supporting a bar with guides positioned a suitable distance apart and pushing down centrally with a curved blade from the top. A low force is indicative of a product which requires little effort by the consumer to break whilst the distance at the break point indicates the degree of flexibility, or conversely brittleness, that the product possesses.

Texture Analysis in action: the Blade Set

The BLADE SET (HDP/BS*) comprises a Warner Bratzler blade, a reversible blade, a slotted blade insert and a blade holder. 

The reversible blade has a knife edge at one end and a flat guillotine edge at the other. In operation, the blade is firmly held by means of the blade holder which screws directly into the Texture Analyser. 

The slotted blade insert is located directly into the Heavy Duty Platform and acts as a guide for the blade whilst providing support for the product.

Application advice - comparing cutting/shearing accessories

We are often asked why there are so many different blade fixture options available from Stable Micro Systems.  

Our range of blades vary considerably in size, material, thickness and sharpness. In general they are used to measure the Bite/Cutting Force of products which in some instances can relate to their ‘Toughness’. The following guidelines may help in clarifying the potential use of each.

Texture Analysis in action: the Cheese Extensibility Rig

The CHEESE EXTENSIBILITY RIG (A/CE or A/CEA†) consists of a heat resistant vessel and double-sided fork probe. 

The vessel and fork assembly is filled with a known weight of cheese and microwaved (A/CE) or oven cooked (A/CEA) until the cheese is molten. 

A sample retaining insert is added to the vessel and the vessel/fork assembly slides into the fixture base, which is securely fastened to the Texture Analyser. The fork is connected to the load cell via a rapid locating adapter.
 

Texture Analysis in action: the Lipstick Break Strength Rig

The LIPSTICK BREAK STRENGTH RIG (A/LC) enables a cantilever test on lipstick samples.

Lipstick is a moulded, solid fatty base containing dissolved and suspended colourants having a number of technical prerequisites. An important property sought by users is that the product must not bend, crumble, crack or break during application.

Selection of the correct base ingredient quantities, for example waxes of specific melting points, is such to formulate a product with moulded stick resilience, which possesses enough rigidity to withstand firm application to the lips by the user.

Texture Analysis in action: the Miniature Kramer/Ottawa Cell

The MINIATURE KRAMER SHEAR/OTTAWA CELL (HDP/MK05* or HDP/MKS*) is particularly suited to reduce the force of bulk shearing/compression of multi particle products or non-uniform products.

It attaches to the HDP/90 Heavy Duty Platform. A 5-bladed head or compression platen can be attached to the arm of the texture analyser depending upon whether a shearing or bulk compression/extrusion test is required.

Texture Analysis in action: the Kramer Shear Cell

Two versions of the KRAMER SHEAR CELL (HDP/KS10 and HDP/KS5) are available.

The 10-bladed HDP/KS10 must be used with a 50Kg loadcell or greater.

The 5-bladed HDP/KS5 can be used with a 25Kg or 30Kg loadcell for soft products, but a 50Kg loadcell or greater is recommended.

Easy locating adapters ensure fast blade removal for cleaning and replacement or further testing. Cells have perspex front panels for precise positioning of the blades close to the sample, and easy removal for cell cleaning.

The cell is used for analysing multi-particle products such as cereals and pickles in sauce together with fruit and vegetables. This test applies a combination of compression, shearing and extrusion.

*Attachments with code prefix HDP/ must be used in conjunction with HDP/90 Heavy Duty Platform. 
   

Texture Analysis in action: the Spaghetti Flexure Rig

The SPAGHETTI FLEXURE RIG (A/SFR) measures the compression and flexure characteristics of uncooked spaghetti, which are of interest when investigating any possible inherent weakness due to sprout damage of the durum wheat, or to incorrect drying procedures.

The test sample is located between upper and lower supports in centrally located holes. The upper support is directly connected to the loadcell and the lower support to the base of the texture analyser. Test samples of 100mm are prepared and the average force and distance to break is measured. 

Developing stable chocolate products for high temperature environments

Nestlé has followed in the footsteps of Mondelez and developed its own non-melting (or temperature tolerant) chocolate especially suited to emerging markets with hot climates.

Conventionally manufactured chocolate consists of sugars, cocoa solids and protein (usually from milk) homogeneously dispersed in fats and fatty substances originating from cocoa butter. Chocolate analogues contain other vegetable fats in partial/total replacement of the cocoa butter fat. Often the continuous fat phase also contains dairy fat.

Cocoa butter typically starts to soften at about 28°C, with consequent loss of the mechanical strength of the chocolate. This means that at the high ambient temperatures frequently encountered in tropical countries, chocolate becomes sticky or even runny. It tends to stick to the wrapper and fall apart when the wrapper is removed, leaving a semi-liquid mass that can often only be eaten with a spoon if cleanliness is desired.

Texture Analysis in action: Metered Dose Inhaler test

The METERED DOSE INHALER or MDI (A/IS) delivers a precise, reproducible dose of drug accurately to the deep lung. 

It is also well accepted by patients who depend on MDI’s in their treatment and therefore it is essential to constantly improve this technology. Patients need to rely on their inhaler to provide them with the required medication which is often at a crucial time when physical strength may be very low.

The metering valve, whose performance is assessed with this test, is a critical component of a finished metered-dose inhaler.

Texture Analysis in action: the Craft Knife and Extended Craft Knife

The CRAFT KNIFE ADAPTER (A/CKB) accommodates a standard 50mm wide craft blade and enables precision cutting of samples.

Hard products can be cut whilst providing a ‘disposable’ blade option if blade blunting is of concern. The blade thickness (0.6mm) enables precision cutting of very small samples (e.g. nuts, seeds) or shearing without compression of very soft or brittle samples (e.g. laminated pastry), or tablets, pastilles and many industrial products.

A high density polythene cutting block and 10 spare blades are provided.

Texture Analysis in action: the Dough Preparation Set

The DOUGH PREPARATION SET (A/DP) is used to measure the characteristics of biscuit dough. 

The set comprises a test cell, aeration plunger and a flattening plunger. 

A sample is placed in the cell, pockets of randomly distributed air are removed by the spiked aeration plunger, and an even surface is achieved by application of the flattening plunger. 

A 6mm cylinder probe is used to measure the consistency of the dough. 

Texture Analysis in action: the Volodkevich Bite Jaws

The VOLODKEVICH BITE JAWS (HDP/VB*) fixture performs an imitative test by simulating the action of an incisor tooth biting through food. 

It comprises of upper and lower jaws which are fitted to the loadcell and Heavy Duty Platform.

A sample is positioned in the lower jaw and the biting action is provided by the compressive movement of the upper jaw shearing into the test sample.
 

Texture Analysis in action: the Crisp Fracture Support Rig

The CRISP FRACTURE SUPPORT RIG (HDP/CFS*)

This rig is used to measure the fracturability of snack foods and potato crisps (known in some countries as chips) by means of a penetration test.

It allows accurate location and quick alignment of the sample and is used with the Heavy Duty Platform.

Texture Analysis in action: the Light Knife Blade and Cooked Pasta Quality/Firmness Rig

The LIGHT KNIFE BLADE (A/LKB) is one of several fixtures specifically designed for cutting tests.

It consists of a small perspex blade with a fitting that locates directly into the loadcell, and is used for small samples which require limited force to cut or break, such as pasta and noodles. 

The sample can be placed either on the HDP/90 Heavy Duty Platform, or directly on the base of the Texture Analyser. 

This blade is an ideal alternative to the Knife Edge blade, which is included in the Blade set.

Texture Analysis in action: the Pizza Tensile Rig

The PIZZA TENSILE RIG (A/PT) is comprised of two four-pronged components. 

The upper component fits directly to the loadcell and the lower to the base of the texture analyser. The rectangular shaped test sample is positioned on the attachments using the prongs. 

The tensile force and extension to break the sample is measured and used as an indication of pizza toughness.

Assessing haircare performance using texture analysis

'A new polymer generation offering truly multifunctional performance' is an article published by BASF in Germany.
After decades of development and improvement of hair styling polymers there is still room for improvement. Many generations of polymers have been developed over the years, starting from the first synthetic styling polymer – Polyvinylpyrrolidone (PVP) – in the 1950s, based upon a patent from W. Reppe. 

Today’s styling formulations are further optimised by the use of polymer combinations. This is especially true for styling gel and wax formulations.

Texture Analysis in action: The Adhesive Loop Test

The ADHESIVE LOOP TEST (A/LTS) provides a means of assessing probably the most important and yet the hardest to measure property of pressure sensitive materials, the tack. 

The test performs a loop tape method according to FINAT method no. 9. This allows the end user to compare the “initial grab” or “application tack” of different laminates and can be extremely useful to those working with automatic labelling equipment where this property is of particular importance.

Top five journals that focus on Food Texture Measurement

So you’re in the field of Food Texture Analysis? As a consumer, you’ll already appreciate that texture is a major determinant of food acceptance. 

You’ll no doubt want to keep up with the latest academic publications and scientific references in the field. 

Let me present the top 5 journals in our library that will help you remain a ‘Texture Expert’....

Texture Analysis in action: the Bread V Squeeze Rig

The BREAD V SQUEEZE RIG (A/BSR†) enables testing of the softness and springiness of both packaged and unpackaged loaves, thereby giving a good indication of freshness.

A common way to test the softness of a loaf is by squeezing it between the thumb and fingers, creating a ‘V’ shape with the hand. The rig imitates this process and allows repeatable, scientific analysis of the freshness and appeal of bread. 

Texture Analysis in action: the TTC Spreadability Rig

The TTC SPREADABILITY RIG (HDP/SR*) measures the ease with which a product, such as margarine and table spread, or wax, can be applied in a thin, even layer. 

It comprises of a male 90° cone probe and five precisely matched female perspex cone shaped product holders.

The material is either deposited and allowed to set up in the lower cone holders in advance of testing, or is filled with a spatula and then the surface levelled. The sample holders can be stored in frozen, refrigerated or ambient environments before testing of the sample.

Maximising meat texture – 3 popular ways to test meat

A CONVENIENT CONUNDRUM

Convenience is a key driver in the purchasing decision of today’s consumers. As they become increasingly time-poor, there is a surge in demand for easy-to-prepare foods. 

This is reflected in the success of the ready meals market which has flourished throughout Europe, even in countries where the home-cooked family meal has long been traditional. Benefitting, in particular, from the growth of the ready meals sector is the meat industry. 

In their quest for convenience, consumers are disinclined to compromise on food quality, which leaves manufacturers with the difficult task of balancing the two. Products must be reminiscent of ‘home cooking’, while being quick and easy to prepare. Although taste is a big concern, a product’s texture and mouthfeel is equally important to the consumer’s overall enjoyment. Undesirable texture can significantly reduce the appeal of ready meal foods, resulting in poor sales.

Texture Analysis in action: the Forward Extrusion Cell

The FORWARD EXTRUSION CELL (HDP/FE*) measures the compression force required for a piston disc to extrude a product through a standard size outlet in the base of the sample container. 

The sample container can accommodate base discs with outlet diameters of 3,5,7 or 10mm diameter, their selection depending upon the consistency of the sample. 

The complete sample container is located into a centralising insert fitted into the Heavy Duty Platform and a piston disc is attached to the loadcell using a probe adapter.

Top ten books to understand Food Texture Analysis

So you’re new to Food Texture Analysis? As a consumer, you’ll already appreciate that texture is a major determinant of food acceptance. 

Food companies use sensory evaluation panels to check the texture of their products for both product development and quality control purposes, but many companies supplement sensory evaluation with instrumental measurements.

You’ll no doubt want to educate yourself and obtain a background in the science of this field. Let me present the top ten books in our library that will help you become a ‘Texture Expert’...

Texture Analysis in action: the Fracture Wedge Set

The FRACTURE WEDGE SET (A/WEG) comprises of upper and lower wedges each with a cutting angle of 30° and 30mm width. 

The lower wedge is fixed directly to the base of the Texture Analyser and the upper wedge is connected directly to the loadcell. 

Typical examples include cheese and vegetables which are held on the lower wedge and the force to fracture is measured. The maximum sample width is limited to 30mm.

Getting a hold on the texture of gluten free products

I hadn't given my sister's Coeliac Disease much thought until she invited me for a Sunday tea party last weekend. 

Whilst, as a food scientist, I appreciated that she had some adapting to do in her diet, I hadn't fully appreciated just what a wide range of products she'd been through to select the products that were as close as possible to the palatability of the gluten-loaded products she used to enjoy.

When gluten is removed from baked products, taste and mouthfeel are usually compromised – and it’s difficult for consumers to find gluten-free alternatives that taste good and have desirable texture properties. Gluten-free bakery product formulations have the tendency to be dense, have no structure, crumble easily and are prone to quicker staling.  Bakery formulators are striving to find solutions to these problems and quantify the effects of their efforts.

Measure Bending Force

BENDING FORCE: the physical nature of some products make them more suitable for testing via a bending test. 

Generally the higher the force to bend (usually up to the point of break) the firmer the sample. 

The force and distance references at the point of break provide a measure of BREAK STRENGTH by this action.

STIFFNESS is associated with a material that cannot easily be bent and therefore has a high degree of hardness and usually lacks flexibility.

FLEXIBILITY is the opposite of this and is a characteristic of a product that can be bent, flexed or deformed to a much higher degree of deformation before failing. 

Measure Compressibility

The COMPACTABILITY/COMPRESSIBILITY of a product is its ability to be compacted or compressed, usually to a large degree of deformation.  

This can be a required property of, for example, the formation of cosmetic powder tablets or formation of tablets from granules. 

However it may also be undesirable, as would be true of a large amount of packaging material which is usually chosen for its ability to protect a product and therefore resist compaction to a reasonable extent.

Measure Abrasion Force

ABRASION is the erosion of material from a solid surface by the action of another solid. 

When material is removed by contact with hard particles, abrasive wear occurs. The particles either may be present at the surface of a second material or may exist as loose particles between two surfaces.

Abrasive materials are widely used across a variety of industries for polishing, grinding, honing and other similar processes. The efficacy of these materials relies on their frictional properties, which can be calculated as the force required to draw the material across a given surface. Assessment of these properties will allow manufacturers to evaluate the suitability of their products for a specific use. The test results will also highlight differences between grades or brands of abrasive materials.

Measure Consistency

CONSISTENCY is commonly the textural property possessed by dairy products, sauces, syrups and pharmaceuticals lotions (i.e. fluid products). 

It most often makes use of the back extrusion rig for its measurement. Consistency relates to the 'firmness', 'thickness' or 'viscosity' of a liquid or fluid semi-solid. 

Stirring a fluid or semifluid food with a spoon or a finger is frequently used by consumers to give an indication of viscosity or consistency.  

Measure Stringiness

STRINGINESS/SHORTNESS is the degree (distance) to which a product hangs on the probe when the probe is withdrawn. 

It is a major characteristic of mozzarella cheese or adhesives but is also commonly the textural property possessed by sauces (e.g. ketchup, dessert sauces), confectionery glazes, baked product toppings and undoubtedly, syrups. 

In the adhesive industry this characteristic is sometimes referred to as 'legging' or 'tailing', as stringiness may result in the formation of filaments or threads when the adhesive surfaces are separated. 

Measure Friction Force

FRICTION is a phenomenon that is part of our daily lives - in one sense we would find most difficult to survive without it yet in another it can be most expensive to minimise. 

It can be simply identified as the resisting force that arises when one surface slides, or tries to slide, over another. It is commonly the textural property measured from packaging materials, shaving gels, cosmetic sponges, etc.

Friction can be a limitation to us; for example, the friction of packaging can be a major limiting factor in the speed of packing machines. Additives are often used to improve the lubricity of surfaces, this is known as 'slip'. Polythene is added to packaging to improve slip characteristics.

Measure Swelling

SWELLING is associated with an increase in size or volume of a product.

Swelling applications include tablets, gels, films, pellets, mucosal tissues, super-absorbent polymers, sponges, aquaculture feed, chemical and yeast leavened products, etc. 

Depending on application, swelling can be quantified by measuring changes in force or distance by either (i) compressing a product a slight distance and then measuring how force increases as the product swells, or (ii) applying and maintaining a small force onto the product and measuring the distance change as swelling occurs. 

Measure Cutting Force

BITING/CUTTING FORCE gives an indication of the firmness/hardness of a product.  

Bearing in mind that if a row of top front teeth were pulled from a curve into a straight line they would represent a 'knife edge', using a knife blade gives a close representation of the biting or cutting action.

TOUGHNESS – whilst Hardness/Firmness is usually the textural property possessed by most products, the word 'toughness' or ‘chewiness’ may be substituted for a textural property more associated with the product.  

Measure Tensile Strength

TENSILE STRENGTH is the measure of the force or stress required (resistance to lengthwise stress) to pull a sample to the point where it breaks or before permanent deformation results.  

Usually it is the maximum amount of tensile stress that it can be subjected to before failure, although the definition of failure can vary according to material type and design methodology.

In the fields of material science, mechanical engineering and structural engineering there are three typical definitions of tensile strength:

• Yield strength: the stress at which material strain changes from elastic deformation to plastic deformation, causing it to deform permanently.
• Ultimate strength: the maximum stress a material can withstand.
• Breaking strength: the stress coordinate on the stress-strain curve at the point of rupture.

Measure Springiness

SPRINGINESS is the rate at which a deformed material goes back to its undeformed condition after deforming force is removed. 

It is a measurement of elastic recovery – the textural property possessed not only by baked goods such as cakes or breads but also by novel confectionery products and pharmaceutical materials (e.g. cosmetic sponges).

Measure Rupture Force

RUPTURE FORCE – the force that is required to produce a major break/rupture in a sample – can be related to the firmness and brittleness of a product. It is related to burst force – the force causing a sample to break suddenly and violently into pieces. Rupture force measurement can be crucial for such products as medical implants, which may be required to resemble soft tissue but must remain intact for the duration of their intended residence.

Several other products, such as gel capsules containing vitamins, possess bursting as a desirable property, but must withstand transport and handling before ultimately bursting in the mouth.