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

Thursday, 18 September 2014

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

Light knife blade test using the TA.XTplus Texture AnalyserThe 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.

Comparison of spaghetti texture for three cooking times
Comparison of ‘al dente’ texture of spaghetti
at three different cooking times
 View the Application Video 
The COOKED PASTA QUALITY/ FIRMNESS RIG (A/LKB-F) is identical to the A/LKB except for a 1.0mm flat which is machined along the knife edge. 

A flat perspex insert to fit the HDP/90 is also provided. This system complies with AACC Method 16-50.

A typical graph from a comparative test of three spaghetti samples, each cooked for a different time, is shown here. A variety of graph and chart formats is available, along with all detailed test data, as part of the capability of Exponent software.

Some more information on this fixture:

An AACC Standard method for the measurement of pasta cooking quality, with respect to Firmness, was first approved in 1989 and is now widely used. 

Like most instrumental tests used to evaluate pasta quality, this method involves large deformation measurements on the samples tested. It specifies the use of a knife blade, machined to a 1mm flat across the cutting edge (as shown in Figure 5), which measures the force required to cut five strands of spaghetti (or approximately equivalent width of other pasta forms) positioned adjacent to one another. 

Firmness is defined in this method as the work in grams-centimetre required to shear one piece of pasta (e.g. one strand of spaghetti). The maximum cutting force per unit area is also used as a measure of spaghetti firmness and the results of both of these tests have been found to correlate well with data obtained by subjective cooking tests.

An example of the use of this type of test is in the determination of cooking tolerances of pasta samples according to the raw materials and processing methods utilised (see Figure 6 and Table 2). The mean values are obtained from triplicate measurements of each sample and are the results for single strands of spaghetti.

Some examples of published papers that use this fixture on a TA.XTplus Texture Analyser are listed below: 

BRENNAN, C. S. & TUDORICA, C. M. (2007). Fresh Pasta Quality as Affected by Enrichment of Nonstarch Polysaccharides. Journal of Food Science, 72 (9), 659-665.

BRIJS, K, INGLEBRECHT, J. A., COURTIN, C. M., SCHLICHTING, L., MARCHYLO, B. A. & DELCOUR, J. A. (2004). Combined effects of endoxylanases and reduced water levels in pasta production. Cereal Chemistry, 81 (3), 361-368.

CHOY, A.L., MORRISON, P.D., HUGHES, J.G., MARRIOTT, P.J., SMALL , D.M., (2012). Quality and antioxidant properties of instant noodles enhanced with common buckwheat flour. Journal of Cereal Science, 57(3), 281-287.

CUBADDA, R. E., CARCEA, M., MARCONI, E. & TRIVISONNO, M. C. (2007). Influence of gluten proteins and drying temperature on the cooking quality of durum wheat pasta. Cereal Chemistry, 84 (1), 48-55.

DOXASTAKIS, G., PAPAGEORGIOU, M., MANDALOU, D., IRAKLI, M., PAPALAMPROU, E., D'AGOSTINA, A., RESTA, D., BOSCHIN, G. & ARNOLDI, A. (2007). Technological properties and non-enzymatic browning of white lupin protein enriched spaghetti. Food Chemistry, 101, 57-64.

HATCHER, D. W., BELLIDO, G. G., DEXTER, J. E., ANDERSON, M. J. & FU, B. X. (2009). Investigation of uniaxial stress relaxation parameters to characterise the texture of yellow alkaline noodles made from durum and common wheats. Journal of Texture Studies, 39, 695-708.

HATCHER, D. W. & PRESTON, K. R. (2004). Investigation of a small-scale asymmetric centrifugal mixer for the evaluation of asian noodles. Cereal Chemistry, 81 (3), 303-307.

HATCHER, D. W., DEXTER, J. E. & FU, B. X. (2009). Refrigerated storage of yellow alkaline durum noodles: impact on colour and texture. Cereal Chemistry, 86 (1), 106-112.

HATCHER, D. W., DEXTER, J. E., BELLIDO, G. G., CLARKE, J. M. & ANDERSON, M. J. (2009). Impact of genotype and environment on the quality of amber durum wheat alkaline noodles. Cereal Chemistry, 86 (4), 452-462.

SHIAU, S. & CHANG, Y. (2013). Instrumental textural and rheological properties of raw, dried and cooked noodles with transglutaminase. International Journal of Food Properties, 16 (7), 1429-1441.

SISSONS, M. J., SCHLICHTING, L. M., EGAN, N., AARTS, W. A., HARDEN, S. & MARCHYLO, B. A. (2008). A Standardized Method for the Instrumental Determination of Cooked Spaghetti Firmness. Cereal Chemistry, 85 (3), 440-444.

SISSONS, M., AMES, N., EGAN, N. & RHYMER, C. (2008). A comparison of two instrumental techniques used to discriminate the cooking quality of spaghetti. International Journal of Food Science & Technology, 43, 1323-1329.

VERNASA, M., BIASUTTI, E., SCHMIELE, M., JACKEL, L., BANNWART, A. & CHANG, Y. (2012). Effect of supplementation of wheat flour with resistant starch and monoglycerides in pasta dried at high temperatures. International Journal of Food Science and Technology, 47 (6), 1302-1312.

WOOD, J. A., BATEY, I.L., HARE, R. A., SISSONS, M. J. (2001). A comparison of Australian and imported spaghetti. Food Australia, 53 (8), 349-354. 

We can design and manufacture probes or fixtures for the TA.XTplus texture analyser that are bespoke to your sample and its specific measurement.
Once your measurement is performed, our expertise in its graphical interpretation is unparalleled. Not only can we develop the most suitable and accurate method for the testing of your sample, but we can also prepare analysis procedures that obtain the desired parameters from your curve and drop them into a spreadsheet or report designed around your requirements.

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!

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