UNDERSTANDING CHEESE CRYSTALS AS A MEANS TO DIFFERENTIATE AND ADD VALUE TO ARTISAN CHEESES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0230181
• Project Start Date: Oct 1, 2012
• Project End Date: Sep 30, 2014
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF VERMONT
(N/A)
BURLINGTON,VT 05405

Performing Department
Nutritional Sciences

Non Technical Summary
Traditional hand crafted artisan cheeses are expensive to produce and therefore must command high prices in the marketplace in order to be sustainable. To do so, these cheeses must be clearly differentiated from lower cost mass-produced alternatives in ways that inspire consumers to pay value-added prices. Enthusiasts of traditional artisan cheeses savor the unusual and often-singular characteristics of artisan cheeses, especially when specific characteristics emanate directly from either the traditional practices of the artisan cheesemaker or the natural surroundings. The latter has been studied extensively (e.g., the effect of pasture botanicals eaten by the cow, and the indigenous microflora in the milk and cheese making environment, on cheese flavor) and corresponds to what has called "a taste of place" (Trubek 2009). The effects of traditional practices are less well studied, but the proposed project seeks to advance our understanding along these lines. Specifically, the development of crystals in some of Vermont's long-aged artisan cheeses is almost certainly accentuated by the traditional practices employed in their fabrication. Therefore, the presence of crystals has that potential to differentiate artisan cheeses from mass-produced alternatives in ways that may add value, provided that genuine linkages can be established. Currently, however, the public's view of crystals is largely misinformed, and it will take some effort on the part of the research community to correct widely held misconceptions before crystallization can be used to marketing advantage. Italian scientists have been developing this approach to distinguish traditional Parmigiano Regginano cheese from mass-produced Parmesan copies. Vermont artisan cheese makers can benefit from a similar strategy; that is, through scientific data that support the idea that crystals can be viewed as a natural outgrowth of traditional cheesemaking and aging practices, a "signature of tradition" analogous to Trubek's "taste of place". This work is particularly timely for Vermont Cheddar cheese makers because of the increased popularity of two different niche Cheddar cheeses that seem to be very prone to crystal formation, namely very long aged (i.e., 2 to 5 year) Cheddar cheeses and so-called cloth bound Cheddar cheeses. There are now at least six Vermont cheese makers that produce traditional cloth bound Cheddar cheeses, and most of them also produce other styles of Cheddar that are aged for at least 2 years and thus are probably strong candidates for advanced crystal formation. Beyond traditional Cheddar, Vermont is home to a number other long-aged artisan cheeses that are either clothbound or natural rinded and therefore likely prone to crystallizing; these cheeses also stand to benefit from the proposed research.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
503	3430	2000	100%

Knowledge Area
503 - Quality Maintenance in Storing and Marketing Food Products;

Subject Of Investigation
3430 - Cheese;

Field Of Science
2000 - Chemistry;

Keywords

artisan cheese

crystal

calcium lactate

tyrosine

Goals / Objectives
The presence of harmless crystals in mass-produced cheese is almost always viewed as a defect by the industry and a source of confusion among consumers who mistake the crystals for mold growth and assume that they reflect poor quality and may pose a safety hazard. Therefore, industrial cheesemakers go to great lengths to prevent crystal formation. In many long-aged traditional artisan cheeses, however, crystals are natural occurrences that are almost certainly associated with the traditional practices that are used in artisan cheese production. Therefore, instead of being seen as defects in artisan cheeses, these harmless, odorless and tasteless crystals might be more correctly viewed as intrinsic characteristics that proudly bear witness to the traditional cheese making practices of the artisan. The proposed project seeks to identify factors that predispose some of Vermont's most crystal-prone artisan cheeses to crystal formation, and to relate them to traditional cheese making practices. The ultimate goal is to demystify crystallization so that the public's misconceptions about cheese crystals (i.e., quality defect and potential safety hazard) can be "turned upside down" with respect to traditional long-aged artisan cheeses, enabling crystals to be rightfully viewed as a natural consequence of the traditional practices that make artisan cheeses special.

Project Methods
Cheese varieties that show very high incidences of crystallization will be chosen for study to determine factors that predispose these specific varieties to crystal formation. It is anticipated that several varieties showing high incidences of calcium lactate crystals and several that are prone to tyrosine crystals will be included for study. Light microscopy and low magnification scanning electron microscopy (SEM) will be used to assess whether cheeses with heavy crystal development possess microstructural irregularities that could serve as nucleation sites that promote crystal nucleation. Mineral distribution in crystal regions will be determined by SEM/Energy Dispersive X-ray Microanalysis in order to assist in determining crystal identity, specifically to identify calcium phosphate crystals should they be present. Chemical composition (fat, moisture, salt content and pH) of cheese samples will be determined, as well as D(-) and L(+) lactate as described previously (Rajbhandari and Kindstedt, 2005). Total nitrogen and pH 4.6 soluble nitrogen will be determined by Kjeldahl methods (International Dairy Federation, 1993) to evaluate the extent of proteolysis. Tyrosine will be evaluated by the method of Mistry and Kosikowski (1983). This information will serve to identify aspects of the chemical environment that promote crystallization. Finally, detailed information about the manufacturing practices and environmental conditions employed during aging will be obtained from producers who agree to provide this information. From this information, a profile of manufacturing and aging practices that contribute to the structural and chemical characteristics that predispose the cheese to crystal formation will generated for each cheese variety. The end result will be a data base that explains why many traditional Vermont artisan cheeses are naturally prone to crystal formation.

Progress 10/01/12 to 09/30/14

Outputs
Target Audience: We presented our research and published an abstract at the 2013 and 2014 Annual Meeting of the American Dairy Science Association. We also presented our research tin the form of a keynote address at the 9th Cheese Symposium, held in Cork Ireland on Novermber 12-13, 2014. Changes/Problems: Early in this research we determined that powdered X-Ray diffractometry has powerful capabilities that we can marshall for use in the current project work plan to achieve the project objectives. Therefore, we added this analytical approach to augment the other analyses that we are conducting during this project. What opportunities for training and professional development has the project provided? A graduate student, Gil Tansman, has been trained in the use powderedX-Ray diffractometery and its application to the study of cheese crystals. How have the results been disseminated to communities of interest? We presented our research at the 2013 and 2014 Annual Meeting of the American Dairy Science Association, and at the 9th Cheese Symposium in Cork Ireland in November 2014. We have 2 journal articles published in the Journal of Dairy Science. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Artisanal cheese making has become a vibrant and highly visible component of the Vermont dairy industry. Artisan cheeses must command premium prices in the marketplace in order to be economically sustainable, therefore, they must be readily differentiated from lower cost conventional cheeses through quality attributes that render them more interesting and satisfying, and thus worth paying more for. Crystallization in cheese is a fascinating phenomenon that has the potential to differentiate long-aged artisanal cheeses from lower cost conventional alternatives. The general objectives of this project are to characterize the occurrence of visible crystals in long aged cheeses, identify factors that predispose specific cheeses to specific forms of crystallization, and establish relationships between predisposing factors and traditional practices used in artisanal cheese making. Several accomplishments have been achieved so far towards these goals: 1. We have determined that surface crystals on Cheddar cheese can be very complex and include as many as 4 distinct crystal entities, including L(-) and D(+)/L(-) calcium lactate pentahydrate (CLP), tyrosine, calcium phosphate and an unknown crystal.; 2. We have identified this same unknown crystal in long aged Gouda cheese; 3. We have identified large internal crystals embedded in the body of artisanal raw milk Cheddar cheese to be D(+)/L(-) CLP, a crystalline form almost certainly associated with raw milk microflora; 4. We have identified large internal crystals embedded in the body of long aged Gouda cheese and Asiago cheese to be tyrosine; 5. We have identified extremely large spherical internal crystalline regions, or pearls, embedded in the bodies of long aged Parmigiano Reggiano and Gouda cheeses to be an unusual crystalline form of Leucine which are likely of microbial orgin. These pearls likely contribute significantly to the textural properties of these cheeses and warrant further investigation. ; 6. We have established for the first time the x-ray diffraction pattern for the L(-) form of CLP, which now enables the racemic D(+)/L(-) form and the L(-) forms of CLP to be rapidly and easily differentiated. This discovery will enable powdered x-ray diffractometry to serve as a powerful diagnostic tool for evaluating the factors that predispose CLP crystal formation in cheese.; 7. We have demonstrated the occurrence of 6 unknown crystals, almost certainly variants of calcium phosphate, which are present in the surface smears of artisanal washed rind cheeses. These crystals are likely associated with gritty mouthfeel and zonal softening of the body, and warrant further investigation. We presented our research at the 2014 and 2015 Annual Meeting of the American Dairy Science Association, and published 2 papers in the Journal of Dairy Science. We also present our research in the form of a keynote address at the Ninth Cheese Symposium, held in Cork Ireland in November, 2014.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Rajbhandari, P. and P.S. Kindstedt. 2014. Surface roughness and packaging tightness affect calcium lactate crystallization on Cheddar cheese. J. Dairy Sci. 97:1885-1892. Tansman, G., P.S. Kindstedt and J.M. Hughes. 2014. Powder X-ray diffraction can differentiate between enantiomeric variants of calcium lactate pentahydrate. J. Dairy Sci. 97:7354-7362 Tansman, G. P.S. Kindstedt and J.M. Hughes. 2014. Evaluation of unidentified structural features in hard, aged cheeses and soft, washed rind cheeses by powder X-ray diffractometry, J. Dairy Sci. 97(E. Suppl. 1):496 Tansman, G. P.S. Kindstedt and J.M. Hughes. 2013. Application of an improved X-ray diffraction method to evaluate cheese crystals. J. Dairy Sci. 96(E. Suppl. 1):195 Tansman, G., P.S. Kindstedt and J.M. Hughes. 2015. Crystal fingerprinting: Elucidating the crystals of Cheddar, Parmigiano-Reggiano, Gouda and soft washed-rind cheeses using powder X-ray diffractometry. Dairy Sci Technol. (submitted)

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: We presented our research and published an abstract at the 2013 Annual Meeting of the American Dairy Science Association. Changes/Problems: Early in this research we determined that powdered X-Ray diffractometry has powerful capabilities that we can marshall for use in the current project work plan to achieve the project objectives. Therefore, we added this analytical approach to augment the other analyses that we are conducting during this project. What opportunities for training and professional development has the project provided? A graduate student, Gil Tansman, has been trained in the use powderedX-Ray diffractometeryand its application to the study of cheese crystals. How have the results been disseminated to communities of interest? We presented our research at the 2013 Annual Meeting of the American Dairy Science Association, and will do so again in 2014. We have one journal article in preparation that will be submitted to the Journal of Dairy Science. What do you plan to do during the next reporting period to accomplish the goals? We will apply the advances in powdered X-Ray diffractometry methodology that we developed in the previous project year to study factors that predispose some of Vermont's most crystal-prone artisan cheeses to crystal formation, and to relate them to traditional cheese making practices.

Impacts
What was accomplished under these goals? The general objectives of this project are to characterize the occurrence of visible crystals in long aged cheeses, identify factors that predispose specific cheeses to specific forms of crystallization, and establish relationships between predisposing factors and traditional practices used in artisanal cheese making. Several accomplishments have been achieved so far towards these goals: 1. We have determined that surface crystals on Cheddar cheese can be very complex and include as many as 4 distinct crystal entities, including L(-) and D(+)/L(-) calcium lactate pentahydrate (CLP), tyrosine, calcium phosphate and an unknown crystal.; 2. We have identified this same unknown crystal in long aged Gouda cheese; 3. We have identified large internal crystals embedded in the body of artisanal raw milk Cheddar cheese to be D(+)/L(-) CLP, a crystalline form almost certainly associated with raw milk microflora; 4. We have identified large internal crystals embedded in the body of long aged Gouda cheese and Asiago cheese to be tyrosine; 5. We have identified extremely large internal crystalline regions embedded in the bodies of long aged Parmigiano Reggiano cheeses to be an unusual crystalline form of Leucine; 6. We have established for the first time the x-ray diffraction pattern for the L(-) form of CLP, which now enables the racemic D(+)/L(-) form and the L(-) forms of CLP to be rapidly and easily differentiated. This discovery will enable powdered x-ray diffractometry to serve as a powerful diagnostic tool for evaluating the factors that predispose CLP crystal formation in cheese.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Tansman, G. P.S. Kindstedt and J.M. Hughes. 2013. Application of an improved X-ray diffraction method to evaluate cheese crystals. J. Dairy Sci. 96(E. Suppl. 1):195