Cheese makers to use electronic nose for market gain?

Dairy science moves closer to providing dairy food manufacturers with improved flavour profiles as researchers in the UK use human and electronic noses to identify the smelliest cheeses, writes Lindsey Partos.

The scientists at Cranfield University used an electronic nose for the trial to see if there was any correlation between the data signals they received from the nose, and those cheeses deemed "smelliest" by the human trial panel.

"The results were very good, the top three gave very similar patterns," said Dr Stephen White senior research officer Cranfield University who led the study.

"Cheeses noted for being the least smelliest also gave similar results to each other, but very distinct from the top set," Dr White told FoodNavigator.com.

Implications for the dairy manufacturers are that it may be possible to use the nose to determine the optimum condition of cheese - and consequently the right time to sell a specific cheese type or to eat it.

"The 'smell' profile will change as the cheese matures; the nose could be trained to recognise this point," adds Dr White.

Similarly, the nose could be used to authenticate a particular cheese brand; each cheese will have a characteristic data pattern that could be compared.

Most food companies use human sensory panels to inspect products for scent and flavour quality testing but after testing a few samples, humans lose the ability to differentiate between similar scents and must take a rest. Electronic noses have the potential to test thousands of samples a day, resulting in considerable time saving and costs to the manufacturer.

The sensation of smell is caused by the interaction of odorant molecules with a group of specialised nerve cells called olfactory receptors. The olfactory cells are situated in the olfactory epithelium, a specialised tissue in the nose.

"Electronic noses mimic the mammalian olfactory system by combining non-specific gas sensors with a PARC software to analyse and characterise complex odours without prior separation of the mixture into individual components," explained Dr White.

For the UK study, 15 cheeses, ranging from camembert and roquefort to munster and raclette, were smelt. The smelliest cheeses were washed rind cheeses - Vieux Boulogne hit the number one slot, followed by Pont l'Evêque.

"There was no obvious correlation between the age of the selected cheeses and smelliness, nor type of milk origin, although cows' milk cheeses did dominate the smell chart," added Dr White.

Crucially an electronic nose cannot replace people, it can only compare scents with those that human noses have deemed acceptable.

As an effective tool it is only as good as the calibration, carried out by a human sensory panel, as demonstrated by the Cranfield study.

In addition, noses tend to be good at differentiating between very diverse samples, but this is more challenging when the nose is required to detect nuances of aromas, such as variations between the same cheese variety.