Accelerated ripening of cheese

Since the ripening of cheese, especially low moisture varieties, is a slow 

Ripening is also unpredictable. Hence, there are economic and technological 

The principal approaches used to accelerate cheese ripening are  

Elevated ripening temperatures, especially for Cheddar which is now usually ripened at 6-8°C most other varieties are ripened at a higher temperature, e.g. around 14°C for Dutch types or 20-22°C for Swiss types and Parmesan, and hence there is little or no scope for increasing the ripening temperature. 

Exogenous enzymes, usually proteinases and/or peptidases. For several reasons, this approach has had limited success, except for enzyme-modified cheeses (EMC). These are usually high-moisture products which are used as ingredients for processed cheese, cheese spreads, cheese dips or cheese flavourings. 

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Kebary, K.M.K., El-Sonbaty, A.H. and Badawi, R.M. (1999). Effects of heating milk and accelerating ripening of low fat Ras cheese on biogenic amines and free amino acids development, Food Chem., 64, 67. 

Picon et al. (1997) included phospholipase C with encapsulated protei-nases added to milk to stimulate the release of proteinase in Manchego cheese. The phospholipase, acted on the soy lecithin used to form the capsules, accelerated ripening of the cheese. 

Gaya, P., Medina, M., Rodriguez Martin, M.A., Nunez, M. 1990. Accelerated ripening of ewes milk Manchego cheese the effect of elevated ripening temperatures. J. Dairy Sci., 73, 26-32. 

Liposomes have been used for years as components of drug delivery systems, and as transdermal carriers of active ingredients in the cosmetic industry (307, 308). More recently, liposomes have found use in the food and nutritional supplement industries. Keller (308) lists more than a dozen nutritional products on the market that have been formulated with novel liposome-based delivery systems. In the food area, hposomes have been studied for their ability to encapsulate and provide controlled release of enzymes (309, 310), and liposome-encapsulated enzymes have been used to accelerate the ripening of cheese (311). 

Thus, there is undoubtedly a commercial economic incentive to develop techniques to accelerate the ripening of cheese. However, in spite of a considerable amount of published research, and presumably unpublished work, the number of viable options appears to be rather limited—at present the best method appears to be a hi er ripening temperature. 

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. 

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. 

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). 

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

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. 

Therefore, studies on the acceleration of cheese ripening have focussed on proteolysis, especially in hard, low-moisture varieties, in particular Cheddar. Low-fat cheeses have attracted much attention recently such cheeses have poor texture and flavor and the techniques being considered to accelerate the ripening of normal cheeses are being applied to low-fat cheeses also. The third area of interest is the production of cheese-Uke products, e.g., enzyme modified cheeses, for use in the preparation of food products, e.g., processed cheeses, cheese sauces, cheese dips, etc. 

Literature on the acceleration of cheese ripening and related topics has been reviewed extensively (e.g.. Law, 1984,1987 Fox, 1988-1989 El-Soda and Pandian, 1991 El-Soda, 1993 Wilkinson, 1993). Therefore, it is not intended to exhaustively review the literature again but rather to provide a summary and suggest possible developments. 

Several studies, especially in Australia, have shown that provided cheese of good composition and with a low count of NSLAB is used, the ripening of Cheddar cheese can be accelerated and its flavor intensified by using higher than normal ripening temperatures. Optimum results have been reported at 13-15°C at which the ripening time required for the production of mature cheese can be reduced by 50% (Folkertsma et al, 1996). Such practices are in fact reverting to traditional methods. 

Since current evidence indicates that the starter cells and their enzymes are responsible for the final stages of proteolysis, i.e., production of small peptides and free amino acids, probably the modification of amino acids and probably other important changes, it would appear that increasing starter cell numbers should accelerate ripening. Much of the recent work on acceleration of cheese ripening has been based on the above assumption and several approaches have been adopted. 

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