Mold-ripened cheese

Penicillium caseicolum produces an extracellular aspartyl proteinase and a metalloproteinase with properties very similar to those of the extracellular enzymes produced by P roqueforti (Trieu-Cout and Gripon 1981 Trieu-Cout et al. 1982). Breakdown of casein in mold-ripened cheese results from the synergistic action of rennet and the proteases of lactic streptococci and penicillia (Desmazeaud and Gripon 1977). Peptidases of both lactic acid bacteria and penicillia contribute to formation of free amino acid and nonprotein nitrogen (Gripon et al. 1977). 

Lipolysis is considered to be an important biochemical event during cheese ripening and the current knowledge have been discussed in detail (Collins et al., 2003, 2004 McSweeney and Sousa, 2000). The formation of short-chain FFAs by the lipolysis of milk fat by lipases is a desirable reaction in many cheese types (e.g., mold-ripened cheeses). The catabolism of FFAs, which is a secondary event in the ripening process, leads to the formation of volatile flavor compounds such as lactones, thioesters, ethyl esters, alkanols, and hydroxyl fatty acids. The contributions of lipolysis to the flavor of bacterially ripened cheeses are limited. 

Martin-del-Campo, S. T., Pickque, D., Cosio-Ramlrez, R., and Corrieu, G. (2007). Evaluation of chemical parameters in soft mold-ripened cheese during ripening by mid-infrared spectroscopy. ]. Dairy Sci. 90,3018-3027. 

Penicillium roqueforti and P. camemberti produce very active extracellular lipases, which are the principal lipolytic agents in mold-ripened cheeses. They preferentially hydrolyze the short-chain fatty acids in milk fat. P. roqueforti produces two lipases, one with an alkaline pH optimum and the other most active at pH 6 6.5, with slightly differing fatty acid specificities (Menassa and Lamberet, 1982). P. camemberti secretes a single lipase with optimal activity at pH 9 (Lamberet and Lenoir, 1976). 

In some mold-ripened cheeses, a very high FFA content (up to 25% of total fatty acids Gripon, 1987) is acceptable [e.g., >66 000 mg/kg for Blue cheese (Horwood et al., 1981) compared to <4000 mg/kg for good quality Cheddar (Bills and Day, 1964)]. High levels of butyric acid characterise Italian hard cheeses and certain pickled cheeses (Fox and Guinee, 1987), [e.g., up to 520 mg/kg for Greek Feta (Horwood et al., 1981) and >3000 mg/ kg for Romano (Woo and Lindsay, 1984)]. An imbalance in flavor constituents can, nevertheless, lead to undesirably rancid or goaty (C4 o-C8 0) or soapy (Cio o-Ci2 o) flavors in these cheeses (Woo and Lindsay, 1984). 

Mold-ripened cheeses are inoculated with mold spores which germinate and, via metabolic transformation, produce additional characteristic flavor compounds. Blue-vein cheeses are good examples. In these cheeses, surface molds, yeasts, and bacteria (micrococci) become dominant as the cheese pH drops due to the lactic flora early in maturation. The main... 

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. 

The odor threshold values for methyl ketones are substantially higher than those for aldehydes (cf. Tables 3.32 and 3.47). Nevertheless, they act as aroma constituents, particularly in flavors of mold-ripened cheese (cf. 10.2.8.3). However, methyl ketones in coconut or palm oil or in milk fat provide an undesirable, unpleasant odor denoted as perfume rancidity . 

Nielsen K.F., Dalsgaard P.W., Smedsgaard J., Larsen T.O. Andrastins A-D, Penicillium roqueforti metabolites consistently produced in blue-mold-ripened cheese. Journal of Agricultural and Food Chemistry, 53 2908-2913 (2005). 

Molimard, P. and Spinnler, H.E. (1996) Review compounds involved in the flavor of surface mold-ripened cheeses origins and properties. J Dairy Sci 79, 169-184. 

Urbach (78) recently discussed the formation of volatile flavor compounds in different varieties of cheeses and provided a compilation of important aroma compounds. A recent qualitative assessment by Sable and Cottenceau (79) surveys the significant flavor volatiles that have been identified in soft mold-ripened cheeses, including Camembert, Brie, blue, Gorgonzola, Muenster, and Limburger, among others. Octen-3-ol, 2-phenylethanol, and 2-phenylethyl acetate are character impact... 

Furtado, M. M. and Chandan, R. C. (1985). Ripening changes in blue-mold surface ripened cheese from goat s milk. J. Food Sci. 50, 545-546. 

Aside from the distinctively-flavored, washed, surface-ripened cheeses mentioned earlier ( 9, 1, 30), methanethiol has been recognized as a contributor also to the flavor of mature mold surface-ripened cheeses, including Camembert and Brie (31, 32,... 

Karahadian, C., and Lindsay, R. C. (1987). Integrated roles of lactate, ammonia, and calcium in texture development of mold surface-ripening cheese. J. Dairy Sci 70, 909-918. 

Certain types of cheeses are ripened by mold fungi. Indeed, the molds responsible for this action have taken... 

The Sterilamp ultraviolet tube producing a minute amount of ozone has been used to destroy mold on Cheddar cheese during ripening 13, 14). Ewell (11) has reported that less than 0.2 p.p.m. by volume will extend the holding time by 11 weeks at 69° F. and 80 to 85% relative humidity before the appearance of visible mold on the cheese. The ozone also oxidized the odor in the room. 

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