Bitter flavors cheese

Puspitasari, N. L., Lee, K., and Greger, J. L. (1991). Calcium fortification of cottage cheese with hydrocolloid control of bitter flavor defects. /. Dairy Sci. 74,1-7. 

Many enzymes extracted from higher plants have been tried for clotting cheese milk (Burnett 1976), however, attempts to use them have been unsuccessful. Most plant proteases are strongly proteolytic and cause extensive digestion of the curd, which has resulted in reduced yields, bitter flavors, and pasty-bodied cheese. 

Visser, S., Hup, G., Exterkate, F. A. and Stadhouders, J. 1983. Bitter flavor in cheese. 2. Model studies on the formation and degradation of bitter peptides by proteolytic enzymes from calf rennet, starter cells and starter cell fractions. Neth. Milk Dairy J. 37, 169-180. 

Chymosin produces cheese free of bitter flavor and of excellent texture. The use of other acid proteases such as pepsin and many of the microbial rennets in the coagulation step often leads to bitter flavor and a soft texture after ripening. 

By very carefully choosing the protease and its level, very strong flavored cheese can be produced in a short time. However, it is very difficult to produce the proper balance of flavor and to avoid bitter defects in real applications. To varying degrees, all protease treatments will increase the softness of the final product, thus adding another defect the cheese manufacturer has to minimize... 

Traditionally fermented dairy products have been used as beverages, meal components, and ingredients for many new products [60], The formation of flavor in fermented dairy products is a result of reactions of milk components lactose, fat, and casein. Particularly, the enzymatic degradation of proteins leads to the formation of key-flavor components that contribute to the sensory perception of the products [55], Methyl ketones are responsible for the fruity, musty, and blue cheese flavors of cheese and other dairy products. Aromatic amino acids, branched-chain amino acids, and methionine are the most relevant substrates for cheese flavor development [55]. Volatile sulfur compounds derived from methionine, such as methanethiol, dimethylsulflde, and dimethyltrisul-fide, are regarded as essential components in many cheese varieties [61], Conversion of tryptophan or phenylalanine can also lead to benzaldehyde formation. This compound, which is found in various hard- and soft-type cheeses, contributes positively to the overall flavor [57,62]. The conversion of caseins is undoubtedly the most important biochemical pathway for flavor formation in several cheese types [62,63]. A good balance between proteolysis and peptidolysis prevents the formation of bitterness in cheese [64,65],... 

Organic acids may exhibit other sensory properties. For example, citric acid possesses sweet-and-sour sensory notes, and succinic acid has a salty-bitter taste. On the other hand, the typical taste and flavor of Emmental cheese can be ascribed to the propionic acid and a few other compounds, such as proline. In fact, taste and flavor result from the combination of different food constituents in definite proportions. Raw meat smells much like lactic acid, which arises from postmortem anaerobic glucolysis and determines the pH of meat, its final properties, and microbial stability. This same organic acid has been related to the inhibition of certain pathogenic bacteria in yogurt (3). Table 1 lists the reported threshold concentrations for various organic acids in different media (4-6). 

Bullens, 1994 Anonymous, 1996). Textural defects include increased firmness, rubberiness, elasticity, hardness, dryness, and graininess. The negative flavor attributes of reduced-fat Cheddar include bitterness (Ardo and Mansson, 1990) and a low intensity of typical Cheddar cheese aroma and flavor (Banks et al., 1989 Jameson, 1990). Approaches used to improve the quality of reduced-fat cheese include ... 

Unfortunately, most flavor researchers have been slow to utilize the speed and sensitivity that HPLC offers. Although bitter amino acids and peptides have been reported in cheese and casein (36, 37) and in yoguart (38) all the analyses were done by traditional methods. 

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. 

In cheese, a matrix effect could modulate salty and bitter perception in different ways and evolve during the maturation process. The composition of the matrix and physiological parameters had to be taken into account to better understand temporal release and perception of flavor. The study of the relationships between sensory and aroma release gave reliable results only for sulfury note which was the most intense and due to well identified and specific compoimds. 

Enzymes. The use of enzymes is an integral part of many important processes in food production. Hydrolytic enzymes especially are employed on an industrial scale, mainly because no costly regeneration of cofactors is required, in contrast to oxidoreductases. The release of specific fatty acid profiles by lipases in the course of cheese manufacture, or the cleavage by proteases of peptide fragments in protein hydrolyzates that otherwise will cause bitterness are examples for the impact of enzyme-catalyzed reactions on the final flavor of foods (5). 

While the effect of emulsifying salts per se on the flavor of processed cheese is difficult to quantify because of the influence of the many processing conditions thereon, it is generally recognized that sodium citrates impart a clean flavor while phosphates promote off flavors such as soapiness (in the case of orthophosphates) and bitterness (Templeton and Sommer, 1936 Scharf, 1971 Meyer, 1973 Price and Bush, 1974). Potassium citrates also tend to cause bitterness (Templeton and Sommer, 1936). 

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). 

While lipases play a major role in determining the flavor of many cheeses, proteolytic activities are often considered more important to the flavor of some hard cheeses, e.g., Cheddar. The use of proteinases becomes problematic since these enzymes often produce bitter peptides. Thus, the manufacturer typically has to use a balance of proteinases and peptidases the peptidases are necessary to break down the bitter peptides [59]. 

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