Enzyme-modified cheese, flavoring

An extension of this technology lead to the development of enzyme modified cheeses or EMC which are a very important product. The basic function of the process was to shorten the ripening time of a mature cheese without losing flavor. The potential financial gains are obvious. Young cheeses are subjected to a controlled lipolysis and proteolysis which is brought about by adding suitable microbial enzymes (8). After thermal inactivation of the enzymes, a pasty product is obtained which can have a flavor intensity of up to 20 times that of the mature cheese. 

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. 

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. 

Flavor has been reported to develop very rapidly (1 week) in slurries containing 40% solids. Such systems have been used to screen exogenous enzymes. Fast-ripening slurries could be useful in the preparation of cheese sauces, cheese flavoring, processed cheeses, etc. Enzyme-modified cheeses, which can be regarded as being based on the slurry principle, are used commercially as ingredients in processed cheese and cheese products. 

Enzymatically modified cheeses developed to accelerate the ripening and flavor building blocks can be produced by controlled proteolytic and/or lipolytic enzyme treatment of natural cheese. The most popular enzyme-modified cheeses include Cheddar, Swiss, Parmesan, Romano, Brick, and Blue cheeses [95]. 

The key to producing Enzyme-modified cheeses (EMCs) is the proper choice of enzymes and their apphcation under optimal conditions. The majority of research in this area has been on the hpase enzymes. A wide variety of hpase enzymes are commercially available. These enzymes come primarily from animal or microbial sources. Lipase choice is critical because each hpase has a specificity for hydrolysis thereby determining the free fatty acid profile (a key determinant of flavor) in the EMC [54]. 

Seasonings based on dairy products — Cheeses and sour creams are commonly used in snack seasonings. Natural cheeses are often used for label or familiarity purposes. Enzyme modified cheeses or creams are typically used to carry the flavor due to both flavor strength and cost issues. The dairy character of the seasoning may be fortified with other natural flavorings, e.g., lactic acid, butyric acid, diacetyl, etc. Examples of dairy-based snack seasonings are presented in Table 14.6 and Table 14.7. 

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. 

A Romano cheese-like aroma was produced from a butter-fat emulsion by treating it with a crude enzyme mixture isolated from Candida rugosa. The emulsion consisted of 20% butterfat and 1.5% Tween 80 in a buffer solution. The treated emulsion was held at 37°C for three hours and then aged at room temperature for three days to develop the cheese-like flavor. The volatile flavor components were isolated from both the enzyme modified butterfat (EMB) and a commercial sample of Romano cheese. The flavor isolates were separated into acidic and nonacidic fractions and analyzed by gas chromatography-mass spectrometry. The results showed good correlation between the acidic fractions of the two samples. The acidic fractions contained similar relative concentrations of eight short-chain fatty acids (C2 - Cj q). Methyl ketones and esters were major components in the nonacidic fraction of the EMB. 

Acidic Components. The Romano cheese-like flavor of the enzyme-modified butterfat led to a study of its volatile flavor compounds. Table I lists the compounds identified, their absolute concentra-... 

Table II. Volatile Flavor Compounds Identified in the Nonacidic Fractions from Enzyme-Modified Butterfat (EMB) and Romano Cheese...

Fat-based flavors are produced by the modification of fats particularly in dairy products, like creams, butter fat, and cheese. Enzyme-modified creams are generally produced as a result of controlled lipase treatment of dairy cream. Similarly, lipases are also utilized for the manufacturing of enzyme-modified butterfat products from emulsified anhydrous butterfat. 

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