Romano cheese flavor

Production of a Romano Cheese Flavor by Enzymic Modification of Butterfat... 

The composition of the samples is very similar. Both contain eight n-fatty acids (C2 - C q). In addition, sorbic acid, a preservative, was present in the commercial product. The quantity of the acidic components isolated from the volatiles of the EMB sample was more than three times greater than that of the commercial Romano cheese. Harper (12) reported that butanoic acid and other higher fatty acids may be related to the intensity and character of Romano cheese flavor. 

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. 

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. 

A microbial esterase, Mucor miehei esterase, has been extensively studied for flavor development in cheese and was found to produce flavor notes resembling those of Fontina and Romano cheeses (4). 

The purpose of this study is to investigate the production of a Romano cheese-like flavor by enzyme modification of butterfat. Candida rugosa was selected for enzyme modification of butterfat since it possesses a high lipase activity. 

Romano Cheese and Butterfat. The volatile flavor compounds were isolated from the EMB sample, a commercial sample of Romano cheese and a butterfat control sample by vacuum steam distillation. Volatiles were isolated from 2.5L EMB in five batch isolations. The EMB was mixed in a Waring blender prior to each isolation. Romano cheese was obtained from a commercial source (Stella Romano cheese, Universal Foods Corp., Milwaukee, WI). Volatiles were isolated from 700 gm Romano cheese in five batch isolations. One hundred and forty grams of cheese were cut into pieces for each isolation and slurried with 360 ml 0.1% sodium phosphate buffer solution in a blender. Volatiles were also isolated from 500 ml of butterfat emulsion control sample (207. butterfat). 

A crude enzyme mixture was isolated from the fermentate of Candida rugosa (ATCC No. 14,830), which is reported to produce high activity lipases ( ). The enzyme mixture was added to a 20% butterfat emulsion. A cheese-like flavor developed after 3 hours of incubation at 37°C. A desirable Romano cheese note developed after continued incubation at room temperature for three days. Nelson (6) studied lipolyzed butterfat flavor and concluded that the surface active characteristics of both fatty acids and mono- and diglycerides were important in the lipolyzed system. A tempering period of hours or even days was usually required to establish equilibrium at the interface of aqueous and fat phases. He pointed out that the lipolyzed flavor appeared to intensify as the equilibration proceeded and that this intensification was sometimes mistaken for residual lipolytic activity. 

Sensory Evaluations. Summary descriptions of the aroma and flavor-by-mouth of the EMB were established by a panel of five trained flavorists. The aroma of the neat sample was described as strong cheesy, strong Romano cheese-like with slight milky, creamy, ketonic and soapy notes. The aroma of the sample in a 0.5% NaCl solution at a level of 0.6% was described as soapy and milky with slight Romano cheese-like, acid and ketonic notes. The flavor-by-mouth of the sample in the NaCl solution was described as containing slight sharp cheese, bitter and waxy notes. 

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-... 

Nonacidic Components. Figure 1 shows the total ion chromatograms obtained from the nonacidic fractions of the flavor isolates. A total of 22 compounds were identified in the EMB and 12 in the Romano cheese. Table II lists the volatile flavor compounds identified in the nonacidic fractions. 

A series of ethyl esters of fatty acids, from butanoate to tetradecanoate, were identified in the EMB. Two esters, ethyl oc-tanoate and ethyl nonanoate, were found in Romano cheese. Esters are important flavor compounds in cheeses however, a high concentration of esters may cause a "fruity" defect in cheese flavor, y- and 6-dodecalactone were identified in the EMB sample as well as in Romano cheese. Lactones are well distributed in food flavors. 

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

Comparison of the acidic volatile profiles indicates that the EMB is similar to Romano cheese. This correlates well with the flavorists impressions of the aroma and flavor-by-mouth of this sample. Nonacidic volatile flavor profiles of EMB and Romano cheese are dissimilar. This indicates different formation pathways for these two samples. Current studies are investigating applications of the EMB as a flavoring agent and the feasibility for commercial application. 

Romano cheese 16 Label, flavor, appearance Cheddar cheese 7 Label,... 

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). 

Several varieties of the popular Italian cheeses owe their characteristic flavor to the action of lipolytic enzymes. Romano is a very hard, ripened cheese. Originally, it was made from ewe s milk it is now also made from cow s and goat s milk. The sharp, peppery-like flavor, traditionally termed "piquant", results from extensive lipolysis ( 1). Long and Harper (2) and Arnold e t al. (3)... 

Lipolysis is considered to be undesirable in most cheese varieties. Cheddar, Gouda, and Swiss-type cheeses containing even a moderate level of free fatty acids would be considered rancid however, certain cheese varieties are characterized by extensive lipolysis (e.g., Romano, Parmesan, and Blue cheeses). Bills and Day (1964) quantified FFA ( 2 0 to Cj8 3) in 14 Cheddar cheeses with wide variations in flavor but found only small differences, qualitatively or quantitatively, between cheeses of different flavor. The... 

The total concentration of free fatty acids is usually determined by extrac-tion/titration methods or spectrophotometrically as Cu soaps. Early attempts to quantify the concentration of individual short-chain fatty acids involved steam distillation and adsorption chromatography. Complete separation and quantitation of free fatty acids can be achieved by GC, usually as their methyl esters, for which several preparative techniques have been published. Free fatty acids are major contributors to the flavor of some varieties, e.g., Romano, Feta, and Blue in the latter, up to 25% of the total fatty acids may be in the free form. Short chain fatty acids are important contributors to cheese aroma, while longer chain acids contribute to taste. Excessive concentrations of either cause off-flavors (rancidity) and the critical concentration is quite low in many varieties, e.g., Cheddar and Gouda. 

The varied selections of cheeses enjoyed today are due in part to the action of enzymes lipases. The lipases contribute to the distinctive flavor development dming the ripening stage of cheese production. ° Lipases are a class of enzymes that can act on the butterfat of cheese in order to produce flavors that are characteristic of different types of cheeses. Specific lipases are responsible for the flavors we enjoy in cheeses ranging from the piquant flavor (typical of Romano and provolone cheeses) to the distinct flavors of blue and Roqnefort cheeses. The environmental benefits are less discarded cheeses and less wasted production. The consumer benefits are the wide variety of flavors and the high qnality of a variety of cheeses. 

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]. 

In the dairy industry, lipases are used in the hydrolysis of milk fat. Applications include flavor enhancement of cheeses, acceleration of cheese ripening, manufacture of cheeselike products, and lipolysis of butterfat and cream. Sources of lipases for cheese enhancement are the pancreatic glands or pregastric tissues of lamb, calf, or kid. Each pregastric lipase leads to its own characteristic flavor pattern, and these enzymes are essential in the production of quality cheeses such as Romano and provolone [15]. Pregastric lipases have also been used for the treatment of calf diarrhea or scours [15] and have potential for the treatment of malabsorption syndrome in children. 

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