Media Contacts:
Dr. MaryAnne Drake, 919/513-4598
Mick Kulikowski, News Services, 919/515-3470

August 2, 2004

Researchers Unlock the Secret Behind Nutty-Flavored Cheddar Cheese

FOR IMMEDIATE RELEASE

Relationship between 3-methylbutanal concentration and nutty flavor intensity in aged Cheddar cheese models.

North Carolina State University researchers have discovered some of the chemical compounds that contribute to nutty flavor in Cheddar cheese.

After analyzing more than 50 aroma-active chemical compounds in Cheddar cheeses, lead author Dr. MaryAnne Drake, NC State associate professor of food science; Dr. Youngmo Yoon, postdoctoral researcher at NC State; and researchers from the University of Illinois and Turkey found that specific volatile chemical compounds – the Strecker aldehydes 2-methylpropanal, 2-methylbutanal and 3-methylbutanal – were detected in higher amounts in Cheddar cheeses with nutty flavors when compared with Cheddar cheeses without nutty flavors.

Further, the study team discovered that adding Strecker aldehydes to young Cheddar cheese models – aged less than four months – resulted in malty/nutty flavor. Adding Strecker aldehydes to Cheddar cheese models aged for nine months or more increased nutty flavor perception.

The results were published in the Journal of Dairy Science.

Drake says the scientists were surprised by the results. Compounds that were previously thought to impact nutty flavor in Cheddar cheese appeared to have no effect, the researchers discovered.

Most nutty-flavored Cheddar cheeses are older, Drake says, and tend to be higher-end table cheeses.

“Nutty flavor is a very elusive flavor that is difficult to pinpoint,” Drake says. “It is considered a desirable flavor and it only occurs in extremely aged Cheddar cheeses. Usually a cheese will not have nutty flavor before it’s six to nine months old.”

Who distinguishes the subtle differences between, say, nutty-flavored cheeses and malty-flavored cheeses? A panel of specially trained tasters who utilize a unique cheese flavor wheel – a cheese lexicon – developed by Drake and her colleagues.

Drake’s previous work on the cheese wheel – which includes flavors like waxy/crayon, bell pepper and fruity, among many others – characterized nutty flavor as “nut-like aromatic associated with different nuts.” Lightly toasted unsalted nuts, unsalted wheat thins and roasted peanut oil extract were used as guides for nutty flavor.

For this study, highly trained testers sniffed and tasted a variety of Cheddar cheeses, dividing them into nutty and not-nutty categories. Strecker aldehydes were detected in higher amounts in nutty-flavored Cheddar cheeses than in not-nutty-flavored Cheddar cheeses.

After the incorporation of Strecker aldehydes into young and older Cheddar cheeses that were confirmed by testers to be free of nutty flavor, testers reported malty/nutty flavors in young cheese and increased nutty flavor in older cheeses.

Certain amino acids must be present in order for the production of Strecker aldehydes and resulting nutty flavor in Cheddar cheese. Drake says that there may be three methods to accelerate nutty flavor: the use of starter cultures capable of releasing the required amino acids; addition of the required amino acids into cheese milk or slurry; and accelerating the conversion rate of the required amino acids into aroma compounds.

Since nutty flavor is a desirable trait and occurs predominantly and unpredictably in aged cheese, the next step is to find a way to promote nutty flavor in younger cheeses, Drake says.

“Cheese is an orchestra of the specific balance of complex, volatile chemical compounds,” Drake says. “If we’re going to help deliver specifically the right products to the right customers, we have to know what causes particular flavors, whether they’re desirable or undesirable,” Drake says.

The research was funded by Dairy Management, Inc.

- kulikowski -

Note to editors: An abstract of the paper follows.

Characterization of Nutty Flavor in Cheddar Cheese
Authors: M.A. Drake, Y. Yoon, North Carolina State University; Y.K. Avsar, Mustafa Kemal University, Antakya, Turkey; Y. Karagul-Yuceer, Onsekiz Mart University, Canakkale, Turkey; T.K. Singh, K.R. Cadwallader, University of Illinois
Published: June 2004, in the Journal of Dairy Science

Abstract: The objectives of this study were to determine the volatile components responsible for the sensory perception of nutty flavor in Cheddar cheese. Cheddar cheeses with and without nutty flavors were selected by descriptive sensory analysis. Volatile aroma components from Cheddar cheeses with and without nutty flavors were isolated and characterized using solvent extraction with high vacuum distillation, dynamic headspace analysis, gas chromatography-olfactometry, and gas chromatography-mass spectrometry. More than 50 aroma-active compounds were detected in Cheddar cheeses. Consistent differences were observed between nutty and not nutty Cheddar cheeses. Strecker aldehydes were detected in higher amounts in Cheddar cheeses with nutty flavors compared with Cheddar cheeses without nutty flavors. Strecker aldehydes, dimethyl sulfide, and propionic acid were evaluated in young and aged Cheddar cheese models for nutty flavor by descriptive sensory analysis. Dimethyl sulfide and propionic acid did not contribute to nutty flavor in Cheddar cheese. The addition of Strecker aldehydes to young (<4 months old) Cheddar cheese models resulted in nutty/malty flavor perceived by sensory analysis. When Strecker aldehydes were incorporated into aged (>9 months old) Cheddar cheese models, nutty flavor perception increased. Strecker aldehydes contribute to nutty flavor in aged Cheddar cheese.