Aroma Cheddar cheese

Several of the smaller volatile compounds formed from the catabolism of products of primary proteolysis (e.g., amino acids) can be determined by GC. The development of capillary columns and interfacing GC with MS has noticeably increased the sensitivity of this analysis. Over 200 volatile compounds have been identified in Cheddar cheese. A list of several of these compounds can be found elsewhere (Fox et ah, 2004a Singh et ah, 2003). The instrumental techniques available for the characterization of cheese aroma were also discussed recently (Le Quere, 2004 Singh et al., 2003). 

Manning, D. J. and Robinson, H. M. (1973). The analysis of volatile substances associated with Cheddar cheese aroma. J. Dairy Res. 40, 531-537. 

Bullens, 1994 Anonymous, 1996). Textural defects include increased firmness, rubberiness, elasticity, hardness, dryness, and graininess. The negative flavor attributes of reduced-fat Cheddar include bitterness (Ardo and Mansson, 1990) and a low intensity of typical Cheddar cheese aroma and flavor (Banks et al., 1989 Jameson, 1990). Approaches used to improve the quality of reduced-fat cheese include ... 

Whereas aroma-relevant amounts of y-lactones from raspberries are not detectable, their 5-Cg, 5-CjQ-lactones are enantiopure S-enantiomers [42]. In cheddar cheese-aroma the enantiomeric purity of (5R)-5-lactones (Cjq-C 4) increases with increasing side chain length [68]. 

The extremely elusive nature of the chemical basis of Cheddar-like flavors supports the hypothesis that an unstable aroma compound is involved in the flavor of Cheddar cheese, and this view deserves thorough investigation. The circumstantial evidence in favor of the existence of a Cheddar-like aroma also includes considerations relating to the sensitivity of Cheddar flavor to heat and oxygen, and the fact that the redox of cheese is quite low. Additionally, sulfury or sulfide-like defects as well as brothy flavor-like defects are often encountered in Cheddar cheeses of various compositions and origin. These flavors could reflect either production of excessive amounts of certain sulfur compounds or the absence of certain essential compounds that are initially required to allow formation of a Cheddar compound. While attempts to date have not resulted in the isolation of such a compound, this could reflect the very unstable nature of the proposed compound. Other similar circumstances appear to occur in freshly roasted coffee and nuts where transient... 

Esters. Esters are extremely important aroma compounds and there are many reports that esters are biosynthetic products of bacterial action. Thus, the fruity flavor defect sometimes found in cheddar cheese is due to the presence of esters, principally ethyl butyrate and ethyl caproate (25). Similar esters can be found in beer in which both fusel alcohols and the short chain fatty acids, acetic and butyric, are also present. These materials can undergo esterification, which in this case is mediated by the enzyme alcohol acetyltransferase present in the yeast used for beer fermentation (26). There are a number of esters present in wine which are metabolically produced by the yeast. Of these,... 

Ho s group at Rutger s describe the use of enzymes from Candida rugosa to convert butterfat to a series of neutral and acidic compounds possessing a Romano cheese flavor. Similar technology is used by the food industry to produce enzyme modified cheese from young Cheddar cheese. The final product possesses a more intense natural aroma and taste. Similar techniques could undoubtedly be used for the production of other natural cheese flavors. 

Compounds responsible for cheese aroma are volatile. While some preliminary work on the volatile constituents of cheese was done before 1960, e.g., short chain fatty acids and amines, significant progress was not possible until the development of GC in the 1950s. GC was first applied to the study of Cheddar cheese volatiles by Scarpellino and Kosikowski (1962) and McGugan and Howsam (1962), who used vacuum distillation and cold... 

Dunn H. C., and Linday, R. C. (1985). Evaluation of the role of microbial Strecker-dervied aroma compounds in unclean-type flavors of Cheddar cheese. J. Dairy Sci. 68,2859-2874. 

If one is considering a study of desirable flavor, the task can become very difficult. For example, what if one was asked to obtain an aroma profile of aged Cheddar cheese Cheddar cheese flavor varies around the world, and there is absolutely no consensus as to what is a typical Cheddar cheese. Sample selection becomes arbitrary and is left to the prejudices of the researcher. 

Lamparsky, D., I. Klimes, Cheddar cheese flavor its formation in light of new analytical results, in Flavour 81, P. Schreier, Ed., deGrayter, Berlin, 1981, p. 557. Berger, R.G., Aroma Biotechnology, Springer, Berlin, 1995, p. 240. 

Similar aroma profiles had been acquired of the low-fat and full-fat Cheddar cheese with the main differences being in peak intensities. 

For many foods, character impact compounds are unknown or have not been reported to date. Examples of these include Cheddar cheese, milk chocolate, and sweet potatoes. For these foods, the characterizing aroma appears to be composed of a relatively complex mixture of flavor compounds, rather than one or two aroma chemicals. 

By a wide margin, Cheddar is the most popular cheese flavor in North America. Its flavor is described as sweet, buttery, aromatic, and walnut, yet there is no general consensus among flavor chemists about the identity of individual compounds or groups of compounds responsible for Cheddar flavor. Reinec-cius and Milo (80) concluded that butyric acid, acetic acid, methional, 2,3-butanedione, and homofuraneol (5-ethyl-4-hydroxy-2-methyl-(2//)-furan-3-one) are primary contributors to the pleasant mild flavor of Cheddar cheese. Important contributors to Cheddar aroma are 2,3-butanedione, dimethyl sulfide/trisulfide, and methanethiol (80). 

Arora et al., 1995 Engels et al., 1997). Thioesters are formed by the reaction of an FFA with a sulphydryl compound, particularly methanethiol (CH3SH Molimard and Spinnler, 1996 Collins et al., 2003a, 2004). Methylthioesters of short-chain FFAs have been associated with the characteristic aromas of Cheddar and smear-ripened cheeses (Arora et al., 1995 Lamberet et al., 1997). 

The odd-numbered ketones identified in both samples are commonly found in mold-ripened cheeses, such as Blue cheese, and are responsible for their characteristic aroma. Large quantities of these compounds also have been found in nonmold-ripened cheeses, such as Cheddar, Swiss and Romano. These compounds may arise by 8 Oxidation of the appropriate fatty acids (14), or by decomposition of 8-keto acids. 

Benzaldehyde and phenylacetaldehyde were identified in Romano cheese. These two compounds also have been found in Cheddar, Swiss and Blue cheeses. Benzaldehyde has a powerful, sweet, almond-like odor and exists in many foods. Phenylacetaldehyde has a strong, sweet floral, penetrating aroma and is found in many cooked foods. 

The total concentration of free fatty acids is usually determined by extrac-tion/titration methods or spectrophotometrically as Cu soaps. Early attempts to quantify the concentration of individual short-chain fatty acids involved steam distillation and adsorption chromatography. Complete separation and quantitation of free fatty acids can be achieved by GC, usually as their methyl esters, for which several preparative techniques have been published. Free fatty acids are major contributors to the flavor of some varieties, e.g., Romano, Feta, and Blue in the latter, up to 25% of the total fatty acids may be in the free form. Short chain fatty acids are important contributors to cheese aroma, while longer chain acids contribute to taste. Excessive concentrations of either cause off-flavors (rancidity) and the critical concentration is quite low in many varieties, e.g., Cheddar and Gouda. 

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