In cheese ripening

Study on the role of alkaline phosphatase in cheese ripening... 

Exploration of this method for controlled release of enzymes to produce flavors of importance in cheese ripening has been pioneered by Kirby and Law (1986), and was recently the subject... 

The esterase/lipase system of Lactococcus has received relatively little attention in comparison with its proteolytic system. Unlike the situation with lactococcal proteinases and peptidases, little is known about the genetics of lactoccal lipase/esterase. Isolation of lipase/esterase-negative variants of Lactococcus would permit the significance of these enzymes in cheese ripening to be assessed. 

Of the three primary events in cheese ripening, i.e., glycolysis, lipolysis, and proteolysis, proteolysis is usually the rate-limiting one. Glycolysis is normally very rapid and is complete in most varieties within 24 hr therefore, acceleration of glycolysis is not of interest. The modification and catabolism of lactate is either of little or no consequence (e.g., Cheddar or Dutch varieties) or is quite rapid—2-3 weeks (e.g., Swiss types, Camembert)—and consequently its acceleration is not important. Lipolysis is limited in most cheese varieties, exceptions being some Italian varieties, e.g., Romano and... 

On the assumption that proteolysis is the rate-limiting event in cheese ripening, there has been interest for several years in adding exogenous proteinases to cheese curd. The first problem encountered is the method of enzyme addition. Direct addition of the proteinase to the cheesemilk ensures its uniform distribution throughout the curd but since most proteinases are water-soluble, most of the added enzyme is lost in the whey, which is economically undesirable, and significant proteolysis may occur prior to coagulation with consequent loss of peptides in the whey and a reduction in cheese yield. 

Baankreis, R. (1992). The role of lactococcal peptidases in cheese ripening. Ph.D. Thesis, University of Amsterdam, The Netherlands. 

Bhowmik, T., and Marth, E. H. (1990b). Role of Micrococcus and Pediococcus species in cheese ripening A review. J. Dairy Scl 73, 859-866. 

Applications of liposomes in cheese ripening were developed by the 1980s (El Soda, 1986). Enhancement of proteolysis by encapsulated cyprosins was evident 24 h after manufacture of Manchego cheese. Addition of encapsulated cyprosins to milk perceptibly accelerated the development of flavor intensity in experimental cheese through 15 days of age without enhancing bitterness (Picon et al., 1996). The capability of neutral and charged liposomes to entrap the proteolytic enzyme neutrase, and the stability of the preparation, were evaluated in the ripening of Saint-Paulin cheese milk (Alkhalaf et al., 1989). 

Lb.helveticus is used as a bacterial starter in Emmental cheese. Lb.casei occurs normally in cheese milk and cheesemaking equipment and is a part of the natural flora. It seems, however, to have a benefical role in cheese ripening. We compared how these two bacteria differ when growing in milk, investigating two different strains of each bacterium. Lb.casei strains were isolated from cheese and Lb.helveticus strains from pure cultures intended for Emmental cheesemaking. 

Joutsjoki, V., Louoma, S., Tamminen, M., Kilpi, M., Johansen, E., Palva, A. (2002). Recombinant Lactococcus starters as a potential source of additional peptidolytic activity in cheese ripening. Journal of Applied Microbiology, 92,1159-1166. 

The main role of propionic acid bacteria in cheese ripening consists in the utilization of lactate produced by lactic acid bacteria as an end product of lactose fermentation. Lactate is then transformed into propionic and acetic acids and CO2. The volatile acids provide a specific sharp taste and help preserve a milk protein, casein. Hydrolysis of lipids with the formation of fatty acids is essential for the taste qualities of cheese. The release of proline and other amino acids and such volatile compounds as acetoin, diacetyl, dimethylsulfide, acetaldehyde is important for the formation of cheese aroma. Carbon dioxide released in the processes of propionic acid fermentation and decarboxylation of amino acids (mainly) forms eyes, or holes. Propionic acid bacteria also produce vitamins, first of all, vitamin At the same time, an important condition is to keep propionibacteria from growing and producing CO2 at low temperatures, since this would cause cracks and fissures in cheese. 

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