Optimise your Salmon texture testing

Fish is loved by consumers – it is unique, nutritious and well-balanced. The four quality elements of food are texture, appearance, flavour and nutrition.

Compared with the meat of livestock, tissue of fish is more soft and delicate in its chemical composition.

With the development of people's living standards and of the food processing industry, texture has attracted more and more attention. 

A recently published paper describes several texture parameters, analyses various factors affecting fish tissue texture especially the protein composition of fish muscle tissue from 3 aspects – physical factors, chemical factors and post-mortem changes – and mainly reviews the effects of different processing methods such as heating, freezing, salting and smoking on texture of fish meat.

The purpose of this paper is to provide a basis for the application of texture analysis in quality assessment and the development and production of instant products and meet the needs of consumers.

Click or tap here to read more... 

A video has also just been uploaded to YouTube by Tom Ashton, which gives advice on salmon sample preparation and optimising your test repeatability for tensile and shearing texture methods. Click or tap here to view... 

Tom is Executive Director of Xelect Ltd, a spin-out company from the University of St Andrews. The core business of Xelect is the development of genetic markers (e.g. for superior fillet yield, flesh quality and faster growth) for aquaculture broodstock selection. 

Salmon texture testing

A few years ago, Tom took what had previously been used for pizza tensile testing and developed a new tensile strength method to quantify the force required to tear a standardised block of Atlantic salmon muscle with the aim of identifying those samples more prone to factory downgrading as a result of softness and fillet gaping. The new method effectively overcomes problems of sample attachment encountered with previous tensile strength tests.

The repeatability and sensitivity and predictability of the new technique were evaluated against other common instrumental texture measurement methods. The relationship between sensory assessments of firmness and parameters from the instrumental texture methods was also determined.

Data from the new method were shown to have the strongest correlations with gaping severity (r=−0.514,P< 0.001) and the highest level of repeatability of data when analysing cold-smoked samples. The Warner Bratzler shear method gave the most repeatable data from fresh samples and had the highest correlations between fresh and smoked product from the same fish (r= 0.811,P< 0.001).

Click or tap here to see the video...

Meanwhile, an Auckland PhD student is attempting to answer a strange question that could keep certain frozen foods from losing their texture and moisture: "Could the same protein that helps fish survive in freezing conditions make frozen fruits and vegetables taste better?"

Latest results of fish samples analysed using a TA.XTplus Texture Analyser based at Auckland University of Technology showed there was more than 50 per cent less moisture loss in the treated foods, as well as retention of nutritional properties.

Charles Kong, a doctoral scholar at the University of Auckland's School of Chemical Sciences, is exploring whether a naturally-derived anti-freeze could retain texture in foods that traditionally don't freeze well, such as kiwi fruit, strawberries and cherries.

"Basically, we don't like frozen foods – they lose their juiciness, become mushy and have a bland taste," he said. "But the season for the things we like to eat such as strawberries is very short, so my research is aimed at investigating how the anti-freeze protein interacts with food to improve it after freezing."

To read 'Scientist's fishy solution could improve frozen produce', please click or tap here...

To request our article 'The Textural Properties of Surimi', please click or tap here...

There is a Texture Analysis test for virtually any physical property. Contact Stable Micro Systems today to learn more about our full range of solutions.

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

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...