Cheese flavoring from

Blue cheese flavors have been prepared via submerged culture fermentations in a sterile milk-based medium using Penicillium rogueforti(63). The fermentations are conducted under pressure with low aeration rates with optimal flavor production occurring from 24-72 hours. Similarly, Kosikowski and Jolly(64) prepared blue cheese flavors from the fermentation of mixtures of whey, food fat, salt and water by P roqueforti. Dwivedi and Kinsella(65) developed a continuous submerged fermentation of P. roqueforti for production of blue cheese flavor. 

Parmesan or Grana, as it is known in Italy, is a group of very hard bacteria-ripened, granular-textured cheeses made from partially skimmed cow s milk. They originated in Parma, near Emilia, Italy, hence the name. Special lipolytic enzymes derived from animals are used, in addition to rennet, to produce the characteristic rancid flavor. 

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. 

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... 

Cliffe, A. J., Marks, J. D., and Mulholland, F. (1993). Isolation and characterization of nonvolatile flavors from cheese, peptide profile of flavor fractions from Cheddar cheese, determined by reverse phase high-performance chromatography. Int. Dairy. ]. 3,379-387. 

Massouras, T., Pappa, E. C., and Mallatou, H. (2006). Headspace analysis of volatile flavor compounds of Teleme cheese made from sheep and goat milk. Int.. Dairy Technol. 59, 250-256. 

Yvon, M., Thirouin, S., Rijnen, L., Fromentier, D., and Gripon, J. C. (1997). An aminotransferase from Lactococcus lactis initiates conversion of amino acids to cheese flavor compounds. Appl. Environ. Microbiol. 63, 414-419. 

Acting as a source of fatty acids, which when liberated from triacyl-glycerols by the action of lipases, contribute directly to cheese flavor... 

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). 

Lipase preparations from numerous microorganisms, including those mentioned above, have been used in the synthesis of dairy (buttery or cheesy) flavors from milk fat (Arnold et al., 1975 Kilara, 1985) or to enhance flavor development in ripening cheese (Fox, 1988). These include lipases from Rhizomucor (Mucor) miehei (Moskowitz et al., 1977 Huge-Jensen et al., 1987), Achromobacter lipolyticum (Khan et al., 1967), Aspergillus niger... 

McDonald, S.T., Spurgeon, K.R., Gilmore, T.M., Parson, J.G., Seas, S.W. 1986. Flavor and other properties of Cheddar cheese made from rancid milk. Cult. Dairy Prod. J. 213, 16, 19-21. 

Milk fat contains a number of different lipids, but is predominately made up of triacylglycerols (TAG) (98%). The remaining lipids are diacylglycerols (DAG), monoacylglycerols (MAG), phospholipids, free fatty acids (FFA) and sterols. Milk fat contains over 250 different fatty acids, but 15 of these make up approximately 95% of the total (Banks, 1991) the most important are shown in Table 19.1. The unique aspect of bovine, ovine and caprine milk fat, in comparison to vegetable oils, is the presence of high levels of short-chain volatile FFAs (SCFFA), which have a major impact on the flavor/aroma of dairy products. Most cheeses are produced from either bovine, ovine or caprine milk and the differences of their FFA profile are responsible for the characteristic flavor of cheeses produced from such milks (Ha and Lindsay, 1991). 

Odor-active components in cheese flavor, many of which are derived from milk lipids, can be detected using GC-olfactometry (GC-O). GC-0 is defined as a collection of techniques that combine olfactometry, or the use of the human nose, as a detector to assess odor activity in a defined air stream post-separation using a GC (Friedich and Acree, 1988). The data generated by GC-0 are evaluated primarily by aroma extract dilution analysis or Charm analysis. Both involve evaluating the odor activity of individual compounds by sniffing the GC outlet of a series of dilutions of the original aroma extract and therefore both methods are based on the odor detection threshold of compounds. The key odourants in dairy products and in various types of cheese have been reviewed by Friedich and Acree (1988) and Curioni and Bosset (2002). 

Three illustrations are used to review the various approaches taken by the enzyme industry in tailoring enzyme preparations to meet the production and product quality needs of the food industry. Tailored enzyme preparations have been able to convert the corn syrup industry from an acid-based industry to an enzyme-based industry, to overcome the problems created in the baking industry as grain technology improved and automation was introduced, and to rescue the cheese industry as the supply of bovine rennet decreased and the demand for cheese and cheese flavor increased. 

Today, cheese flavored paste and powders, containing from 5 to 100 times the flavor level of native cheese, are available in the marketplace for most cheese varieties. Nearly all of these products are made by using added enzymes with most of them using a blend of enzymes and microorganisms. Selected cheese flavors are produced in a liquid or slurry form in a relatively short time compared to making the true cheese and at a flavor level many fold above the maximum flavor obtainable in the true cheese. 

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. 

Both the spores and the mycelium seem capable of producing methyl ketones from fatty acids (12, 13). Furthermore, both short chain and long chain fatty acids are metabolized, thereby giving rise to an homologous series of methyl ketones, the main ones being 2-pentanone, 2-heptanone and 2-nonanone (14). A number of processes have been developed and patented for producing blue cheese flavor via the fermentation of milk fat (15, 16). Usually the... 

The characteristic flavor of various cheeses is primarily due to the enzymatic action of microbial flora contained in the curd. Enzymes extracted from these microorganisms and reacted with corresponding substrates may also produce a specific cheese flavor. The flavor produced may be economical and could be classified as "natural". 

The composition of the samples is very similar. Both contain eight n-fatty acids (C2 - C q). In addition, sorbic acid, a preservative, was present in the commercial product. The quantity of the acidic components isolated from the volatiles of the EMB sample was more than three times greater than that of the commercial Romano cheese. Harper (12) reported that butanoic acid and other higher fatty acids may be related to the intensity and character of Romano cheese flavor. 

A series of ethyl esters of fatty acids, from butanoate to tetradecanoate, were identified in the EMB. Two esters, ethyl oc-tanoate and ethyl nonanoate, were found in Romano cheese. Esters are important flavor compounds in cheeses however, a high concentration of esters may cause a "fruity" defect in cheese flavor, y- and 6-dodecalactone were identified in the EMB sample as well as in Romano cheese. Lactones are well distributed in food flavors. 

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. 

Karahdian C., Josephson D.B. and Lindsay R.C. (1985b) Volatile compounds from Penicillium sp. contributing musty-earthy notes to Brie and Camembert cheese flavors. J. Agric. Food. Chem., 33, 339-343. 

Lactate in cheese may be oxidized to acetate. Pediococci produce 1 mol of acetate and 1 mol of CO2 and consume 1 mol of O2 per mole of lactate utilized (Thomas et al, 1985). The concentration of lactate in cheese far exceeds that required for optimal oxidation, and lactate is not oxidized until all sugars have been exhausted. The oxidation of lactate to acetate in cheese depends on the NSLAB population and on the availability of O2, which is determined by the size of the block and the oxygen permeability of the packaging material (Thomas, 1987). Acetate, which may also be produced by starter bacteria from lactose (Thomas et al., 1979) or citrate or from amino acids by starter bacteria and lactobacilli (Nakae and Elliott, 1965), is usually present at fairly high concentrations in Cheddar cheese and is considered to contribute to cheese flavor, although high concentrations may cause off-flavors (see Aston and Dulley, 1982). Thus, the oxidation of lactate to acetate probably contributes to Cheddar cheese flavor. 

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