Enzyme cheese ripening

Although not well understood, demethiolation has been noted in some fungi.38 Moreover, evidence for a required enzyme activity was obtained for lactococci (used in cheddar cheese production)40 and a relatively high level of demethiolase activity was present in Kluyveromyces lactis, a cheese-ripening yeast (see below).41... 

Rennets. The use of rennets in cheesemaking is the principal application of proteinases in food processing and is second only to amylases among industrial applications of enzymes. The sources of rennets and their role in milk coagulation and cheese ripening are discussed in Chapter 10 and will not be considered here. 

Influences the activity of enzymes during ripening, and hence affects cheese quality. 

It is the principal factor affecting the water activity of young cheeses and has a major effect on the growth and survival of bacteria and the activity of enzymes in cheese, and hence affects and controls the biochemistry of 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... 

Cheese is a concentrated dairy food produced from milk curds that are separated from whey. The curds may be partially degraded by natural milk or microbial enzymes during ripening, as in cured cheeses, or they may be consumed fresh, as in uncured cheeses like cottage cheese. Most commonly, a bacterial culture with the aid of a coagulating enzyme like rennin is responsible for producing the initial curd. The... 

A Cheddar-type cheese retains 48% of total solids of milk, 96% casein, 4% soluble proteins, 94% fat, 6% lactose, 6% H20, 62% calcium, 94% vitamin A, 15% thiamin, 26% riboflavin, and 6% vitamin C (National Dairy Council 1979). The lactose content varies in freshly prepared cheeses and decreases rapidly during ripening, completely disappearing in four to six weeks. The enzymes and ripening agents responsible for the rate and extent of fat and protein breakdown are fully discussed in Chapter 12, and vitamin variation is discussed in Chapter 7. 

Gripon, J. C., Desmazaud, M. J., Le Bars, D. and Bergere, J. L. 1977. Role of proteolytic enzymes of Streptococcus lactis, Penicillium roqueforti, and Penicillium caseicolum during cheese ripening. J. Dairy Sci., 60, 1532-1538. 

Cheese is ripened for 6 months to 1 year or longer at 5° to 15°C and 70-75% relative humidity. Cheese ripening is a complex process involving a combination of chemical, biochemical, and physical reactions. Proteolytic enzymes, e.g., rennet and lactic starter culture enzymes, hydrolyze caseins to produce flavor compounds and proper body. Lipase and lactase enzymes also hydrolyze their respective substrates to produce a large number of characteristic flavor compounds (Reiter and Sharpe 1971 Harper 1959 Law 1981 Schmidt etal. 1976), including free fatty acids, methanethiol, methanol, dimethyl sulfide, diacetyl, acetone, and others (Moskowitz 1980). 

This liposome enzyme system is a combination of an endopeptidase and an exopeptidase. The enzymes are slowly released after the cheese is put into the aging chamber. Using these liposomes for cheddar cheese production showed that the liposomes were evenly distributed and 90% of the added enzyme was retained in the cheese curd. The resulting cheese ripened in half the normal time with excellent flavor and textural properties. 

In enzyme modified cheese (EMC) the natural cheese is modified with enzymes or micro-organisms which accelerate the changes that occur normally during cheese ripening. Production of cheese on industrial scale is an expensive process. EMC processes have been developed in order to shorten and thus cheapen the process. 

Liposomes have been used by the pharmaceutical industry to deliver a range of drugs. Liposomes are made of phospholipid bilayers with one of more aqueous compartments depending on whether they are unilamellar, multilamellar, or multivesicular vehicles. Because of the bilayer structures they can adopt, they are versatile vehicles as carriers of water-soluble, oil-soluble as well as amphiphilic components. Hence, they can be used to encapsulate a wide range of food components including flavors, oils, amino acids, vitamins, minerals antimicrobials, and enzymes. Their potential applications in the food industry have been discussed by Mozafari et al. (2008)). Examples of the potential applications of liposomes in food include the delivery of cheese ripening enzymes and natural antioxidants (e.g., vitamin E). 

Gorini, an Italian bacteriologist, published results on cheese in 1902 in which he held that the group of bacteria which form lactic acid and attack protein, form digesting enzymes which are the cause of cheese ripening. His work was done on Italian cheese at Milan. 

Harding and Prucha worked, on cheese ripening at Geneva, N. Y., 1900-1910, and concluded that the digestion of toe casein of cheese during ripening is due to toe collective action of native enzymes of milk, bacterial enzymes, and rennet action. 

Rabie A.M. (1989) Acceleration of blue cheese ripening by cheese slurry and extracellular enzymes of Penicillium roqueforti. Lait., 69, 305-314. 

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. 

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