Cheddar cheese flavor development

Arbige, M.V., Freund, P.R., Silver, S.C., Zelko, J.T. 1986. Novel lipase for Cheddar cheese flavor development. Food Technol. 40(4), 91-96, 98. 

Cheese/hutter flavor. Pregastric lipases, have, been used for years to intensify flavor in Menzyme-modified cheese , and for an intensified butter flavor in lipolyzed butter. Generally the fatty acid residues that need to be split off (to generate the right flavor) are the short chain fatty acids, especially the C to C-jq acids typical of Italian cheeses. The butyric acids are produced from butterfat more specifically by newly developed lipases (really esterases) from Mucor meihei and a very new one, from Aspergillus oryzae, especially for cheddar cheese flavor development. The latter enzyme is marketed under the name Flavor Age (4). Flavors produced in this manner are used widely in cheese-flavored snack foods the value of the intensified cheese flavors is on the order of 50 million, but the. value of the enzymes employed is only about 2-3 million. 

Free amino acids are further catabolized into several volatile flavor compounds. However, the pathways involved are not fully known. A detailed summary of the various studies on the role of the catabolism of amino acids in cheese flavor development was published by Curtin and McSweeney (2004). Two major pathways have been suggested (1) aminotransferase or lyase activity and (2) deamination or decarboxylation. Aminotransferase activity results in the formation of a-ketoacids and glutamic acid. The a-ketoacids are further degraded to flavor compounds such as hydroxy acids, aldehydes, and carboxylic acids. a-Ketoacids from methionine, branched-chain amino acids (leucine, isoleucine, and valine), or aromatic amino acids (phenylalanine, tyrosine, and tryptophan) serve as the precursors to volatile flavor compounds (Yvon and Rijnen, 2001). Volatile sulfur compounds are primarily formed from methionine. Methanethiol, which at low concentrations, contributes to the characteristic flavor of Cheddar cheese, is formed from the catabolism of methionine (Curtin and McSweeney, 2004 Weimer et al., 1999). Furthermore, bacterial lyases also metabolize methionine to a-ketobutyrate, methanethiol, and ammonia (Tanaka et al., 1985). On catabolism by aminotransferase, aromatic amino acids yield volatile flavor compounds such as benzalde-hyde, phenylacetate, phenylethanol, phenyllactate, etc. Deamination reactions also result in a-ketoacids and ammonia, which add to the flavor of... 

Manning, D. J. (1978). Cheddar cheese flavor studies I. Production of volatiles and development of flavor during ripening.. Dairy Res. 45,479-490. 

When there is a need, someone will solve it. A patent was issued in 1987 (22) describing a new and novel lipase produced by a mutant strain of Aspergillus that has an accelerating effect on cheese flavor development without lypolytic enzyme associated rancidity. The patent claims that this new lipase will be useful as a ripening accelerator in the production of mild flavored cheeses such as cheddar. 

Methanethiol has been found to be correlated with the development of Cheddar cheese flavor by Manning and coworkers (37, 39, 40), and both nonenzymic (22) and enzymic generation of methanethiol have been proposed as the source of this compound in Cheddar cheese (46). Although the correlation of methanethiol to Cheddar flavor appears statistically valid, difficulties have been encountered in explaining the nature of its flavor-conferring properties in cheese. In addition, uniform production of methanethiol is difficult to achieve commercially, and the rate of its natural formation in accelerated-ripening may not be suitable for achieving typical Cheddar flavors (47, 48). 

In conclusion, these investigations have shown that methanethiol generation by methioninase has potential applications in the development of cheese flavors as well as other for other foods. The use of fat encapsulated enzyme systems functioned well in experimental cheeses, and their use should provide assistance in controlled delivery of methanethiol into food systems during further efforts to elucidate the complex nature of Cheddar cheese flavor. 

Since antiquity, animal milks have been converted by empirical processes to a wide variety of cheeses. With the development of microbiology as a scientific discipline, the critical role of microorganisms - bacteria, fungi, yeasts - in cheese began to be understood. Today, more than 650 cheese types are recognized and the flavor(s) of cheese has (have) now been investigated for more than a century.33 Typically, the situation is complex and the literature is enormous. For instance, more than 200 volatiles occur in Cheddar cheese. In a listing of 58 of these volatiles, 7 are sulfur compounds dimethyl sulfide (DMS),... 

Excessive or insufficient acid development during manufacture can produce variability in the moisture content of cheese and defects in flavor, body, texture, color, and finish (Van Slyke and Price 1952). The rate of lactose fermentation varies with the type of cheese, but the conversion to lactic acid is virtually complete during the first weeks of aging (Van Slyke and Price 1952 Turner and Thomas 1980). Very small amounts of lactose and galactose may be found in cheese months after manufacture. (Huffman and Kristoffersen 1984 Turner and Thomas 1980 Harvey et al. 1981 Thomas and Pearce 1981). Turner and Thomas (1980) showed that the fermentation of residual lactose in Cheddar cheese is affected by the storage temperature, the salt level in the cheese and the salt tolerance of the starter used. 

During cheese ripening, proteases associated with starter culture organisms are released into cheese after cell lysis (Law et al. 1974). The proteolytic activity associated with lysed lactic streptococci is necessary for proper flavor development in Cheddar and other cheese varieties. The role of streptococcal proteases and peptidases appears to be production of flavor compound precursors such as methionine and other amino acids, rather than direct production of flavor compounds (Law et al. 1976A). Additional discussion of cheese ripening is presented in Chapter 12. 

Micrococci comprise approximately 78% of the nonlactic bacteria in raw milk Cheddar cheese (Alford and Frazier 1950). The proteolytic system of Micrococcus freudenreichii functions optimally at 30 °C and at a pH near neutrality (Baribo and Foster 1952). An analysis of pro-teinases present in 1-year-old Cheddar cheese indicates that micrococci may contribute to proteolytic activity (Marth 1963). Proteolytic micrococci also contribute to the ripening of surface-ripened cheeses such as brick and Camembert (Lenoir 1963 Langhus et al. 1945). Micrococcal proteases probably contribute to development of ripened cheese flavor when ripening temperatures are above 10°C (Moreno and Kosikowski 1973). This effect results from degradation of /3-casein. 

Yates, A. R., Irvine, O. R. and Cunningham, J. D. 1955. Chromatographic studies on proteolytic bacteria in their relationship to flavor development in Cheddar cheese. 

Wijesundera, C., Drury, L., Muthuku-marappan, K., Gunasekaran, S., Everett, D.W. 1998. Flavor development and distribution of fat globule size in Cheddar-type cheeses made from skim milk homogenised with AMF or its fractions. Aust. J. Dairy Technol., 53,107 (1 page). 

Law, B.A., Wigmore, A.S. 1985. Effect of commercial lipolytic enzymes on flavor development in Cheddar cheese. J. Soc. Dairy Technol. 38, 86-88. 

Sood, V.K. and Kosikowski, F.V., Ripening changes and flavor development in microbial enzyme treated cheddar cheese slurry, J. Food Set, AA, 1690, 1979. 

Enzymic Generation of Methanethiol To Assist in the Flavor Development of Cheddar Cheese and Other Foods... 

Quantitative studies on the enzymatic generation of methanethiol from methionine showed that methioninase obtained from Pseudomonas putida could be used for the development of flavors. Reactions carried out under anaerobic conditions yielded only methanethiol while aerobic conditions favored conversion of substantial amounts of methanethiol to dimethyl disulfide. Incorporation of free or fat-encapsulated methionine/methioninase systems into Cheddar cheeses resulted in the formation of volatile sulfur compounds, including carbon disulfide, and accelerated rates of development of aged Cheddar-like flavors. Methanethiol, when present alone, was observed not to cause the true, Cheddar-like flavor note in experimental cheeses. 

In these cheeses Brevlbacterlum linens or related coryneforms ([7, 34 35) are responsible for the formation of methanethiol. Perhaps the most significant but least understood occurrence of methanethiol in cheeses is that of Cheddar cheese where it appears to be associated with the development of distinctive, true Cheddar-type flavors. 

Cheese ripening is a slow, and hence an expensive, process, e.g., Parmesan and extramature Cheddar are ripened for at least 18 months. Ripening is still not controllable precisely, i.e., the quality and intensity of flavor cannot be predicted precisely. Therefore, there is an economic incentive for the development of methods for the acceleration of cheese ripening, provided that the flavor and texture can be maintained and characteristic of the variety. 

The overall effect of these various practices, i.e., improved milk quality, pasteurization, defined starters, enclosed cheesemaking equipment, rapid cooling, and low ripening temperature, is the production of very mild cheese, free of off-flavors. While the latter is, obviously, a desirable development, not all consumers are happy with the very mild flavor of modem Cheddar. 

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