Bitterness cheese

Bitter cheese has been found occasionally to be due to bacteria causing the formation of a bitter principle as peptone. 

Celery Seed. Celery spice is the dried ripe fmit of y piumgraveolens L. (UmbeUiferae) a biennial, sometimes aimual, herb native to southern Europe and grown extensively in India, China, Mexico, and the United States. The seed is 0.42 cm long and brown. The odor of the seed is characteristic and warm and the taste somewhat bitter. It is used in tomato ketchup, sauces, soups, pickles, pastries, salads, and certain cheeses. 

Milk from cows affected with mastitis alters the sensory quality of raw milk and cheese (Munro el al., 1984). Sensory defects are reported as increased rancidity and bitterness, factors which are consistent with higher levels of lipolysis and proteolysis (Ma et al., 2000). 

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. 

The gross proteolysis of casein is probably due solely to rennet and plasmin activity (O Keeffe et al. 1978). Bacterial proteases and peptides are responsible for subsequent breakdown of the large peptides produced by rennet and plasmin into successively smaller peptides and finally amino acids (O Keeffe et al. 1978). If the relative rate of proteinase activity by rennet, plasmin, and bacterial proteases exceeds that of the bacterial peptidase system, bitterness in the cheese could result. Bitter peptides can be produced from a,-,- or /3-casein by the action of rennet or the activity of bacterial proteinase on /3-casein (Visser et al. 1983). The proteolytic breakdown of /3-casein and the subsequent development of bitterness are strongly retarded by the presence of salt (Fox and Walley 1971 Stadhouders et al. 1983). The principal source of bitter peptides in Gouda cheese is 3-casein, and more particularly the C-terminal region, i.e., 3(193-209) and 3(193-207) (Visser et al. 1983). In model systems, bitter peptides are completely debittered by a peptidases system of S. cremoris (Visser et al. 1983). 

Mills and Thomas (1980) have provided direct evidence that the level of starter proteinase has a role in the development of bitterness in Cheddar cheese. Using cultures containing different proportions of proteinase-positive and proteinase-negative variants of S. cremoris and S. lactis, they showed that cheeses containing 45-75% proteinase-... 

Mills, O. E. and Thomas, T. D. 1980. Bitterness development in Cheddar cheese Effect of level of starter proteinase. N.Z. J. Dairy Sci. Technol. 15, 131-141. 

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. 

Hamilton, J. S., Hill, R. D. and Van Leeuwen, H. 1974. A bitter peptide from Cheddar cheese. Agr. Biol Chem. 38, 375-379. 

Bitter peptides have been identified in hydrolyzates of casein (12,13), cheese (13a,b), and soy bean (14,15,15a). The bitter taste has been related to the hydrophobic amino acid content (16-20) and to chain length. Ney and Retzlaff (21) established a formula relating the bitterness of peptides to their amino acid composition and chain length. Too large a proportion of hydro-phobic amino acids gives rise to bitterness yet above a certain molecular weight, bitterness is not perceptible even when there are hydrophobic amino acids (21). Peptides that were responsible for bitterness in Cheddar cheese were rich in Pro, which occurred predominantly in the penultimate position (21a). 

The extraction of hydrophobic peptides is normally performed using organic solvents. Several authors have extracted bitter peptides from cheese using a mixture of chloroform and methanol (2 1) (42-44). 

Bitter peptides Casein hydrolysate Cheese, casein... 

Because of the bitterness observed in cheeses in which ripening had been accelerated by the addition of enzymes, a reversed-phase method was developed to study the peptide profile in... 

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). 

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