As the nation prepares to tuck into mounds of Stilton this Christmas, researchers have pinpointed for the first time a particular yeast which enhances the smell of blue cheese.

A study undertaken by the University of Northampton and the University of Nottingham, and funded by the Food and Drink iNet (Innovation Network), has discovered a particular ‘secondary microflora component’ is responsible for boosting the aroma of blue cheese.

The scientists have been looking at the role of the various microorganisms in the production of the East Midlands’ famous blue cheeses, like Stilton.

The mould Penicillium roqueforti is added by manufacturers to produce the ‘blue’ in cheeses but now the researchers can confirm that a yeast called Y. lipolytica directly influences the distinct smell of the popular dairy products.

They used a team of trained sensory experts to test different cheese models which contained varying yeast levels to work out which particular strain was responsible for the aroma.

“The panel was able to discriminate between samples with different yeast levels, suggesting that the variation in microbial flora was noticeable in the aroma. Limiting aroma variation is paramount to producing more consistent blue cheeses,” said researcher Dr Kostas Gkatzionis.

Last year a grant from the Food and Drink iNet, part-funded by the European Regional Development Fund (ERDF) and run by the Food and Drink Forum, helped to prove the fact that secondary microflora was a key influencer when it came to a cheese’s flavour.

These microflora are not added deliberately during cheese production – they are selected during the cheese making process from various sources including the cheese factory environment.

The iNet awarded a second grant so that the research team could develop a small scale cheese model in the lab which allowed the scientists to delve into the role of the secondary microflora in more detail.

And now they‘ve been able to prove that a particular yeast gives blue cheese its distinct aroma.

“Ultimately, we hope this work will lead to greater consistency during production for Britain’s cheese makers, which will help them achieve a greater slice of the worldwide blue cheese market, which is worth millions,” said Food and Drink iNet director Richard Worrall.

The research team, which was run by Dr Kostas Gkatzionis, a researcher in the School of Health at The University of Northampton, in conjunction with his colleague Prof Carol Phillips, and Prof Christine Dodd and Dr Robert Linforth from The University of Nottingham, Division of Food Sciences, along with two postgraduate research students, had a £53,871 grant from the iNet for the second stage of their research. They worked in conjunction with Stichelton Dairy in north Nottinghamshire on the project.

The research findings are being shared with cheese producers across the UK in the hope that it will help them to achieve greater consistency in production.

The model created in the lab will also be used to research other cheese-production issues.

“The development of the mini cheese model provides a tool for cheese producers to investigate other issues that concern the industry, such as the testing of new starter cultures, alternative rennets and the effect of modifications in the production procedure, for example reducing salt,” added Prof Christine Dodd at the University of Nottingham.

The Food and Drink iNet aims to build on the tradition of innovation in the food and drink industry in the region by helping to create opportunities to develop knowledge and skills, and to help research, develop and implement new products, markets, services and processes. It is managed by a consortium, led by the Food and Drink Forum and including Nottingham Trent University, the University of Lincoln, and the University of Nottingham.

It is based at Southglade Food Park, Nottingham, with advisors covering the East Midlands region.

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