The glycaemic index, which ranks the impact of a food on blood sugar levels, is seeing growing interest because of its potential to reduce risk of diseases like diabetes and heart disease.
While science to support this link remains limited, the body of evidence is increasing, and food manufacturers under pressure from government and media are beginning to investigate the use of the GI as a means of improving the nutritional value of their products.
Reading University-based RSSL, which launched a GI testing service in January this year, said it has seen strong interest in the service from manufacturers, ingredient suppliers and distributors, including overseas companies.
"Some of them want to test what they already have but others are interested in reducing the GI of existing products," Simon Hails, head of consumer research at RSSL, told NutraIngredients.com.
Some of the research has been used to develop range extensions already on the market, he added. More than 100 products have gone through trials at RSSL and this number is expected to continue rising.
Hails puts the interest down to the "ongoing high profile nature of the health and nutrition debate".
"The weight of scientific opinion is beginning to come down on the side of GI and its role in offering a balanced diet," he added. "It is founded in science."
RSSL is still seeing interest for low-carb foods, which represent a bigger value on the current marketplace. However Hails expects to see more products labelled with their GI value on UK shelves in the future.
But he noted that an ongoing debate about the value of the glycaemic index over the glycaemic load (GL) is currently holding back product launches. Both give a measure of how blood glucose levels rise immediately after consumption of a food, but GL is related to portion sizes, whereas GI allows for an easier comparison between different products.
"At the moment opinion is shifting back to favour glycaemic load. A lot of people are waiting for a consensus on this, which will be driven by the need for communication to the consumer," explained Hails.
In addition, there is currently no reference to GI in the forthcoming EU Commission Proposal for Regulation of Nutritional and Health Claims so without changes, industry will be significantly restricted in what it can say on product labels.
Yet companies are still investing in tests on their products, which require human volunteers to compare the effect different foods have on blood sugar in comparison with pure glucose. This has prompted the recent launch of GI services in research institutes like RSSL, which has access to thousands of human volunteers on Reading University's campus.
London's Hammersmith hospital, the site of the new company offering this service called Hammersmith Food Research, also has this advantage.
Dr Gary Frost, head of nutrition and dietetics at Hammersmith Hospitals NHS Trust and a director of the new company, said it has "the backing an important research hospital confers in terms of infrastructure and access to human volunteers."
The firm also offers expertise in designing trials of new foodstuffs, and general consultancy.
"We can back our expert measurements with advice on managing the GI of foods and ingredients to achieve the best formulations," said Dr Frost. "GI measurement is only a stage in the process of developing foods and components that could play a part in low GI diets."
Leatherhead Food and Oxford Brookes university also offer GI testing facilities to food makers.