Cheese flavour amino acids

Owing to very low thresholds, volatile sulfur compounds (VSCs) usually have prime impact on food aromas they are found in lots of natural sources, including fermented foods (e.g. wine, beer, cheese), and act as both flavours and off-flavours [249, 250]. Although their biogenetic formation has been elucidated in detail, only few biotechnological processes with potential for commercial application have been reported. The sulfur-containing amino acids L-methionine and L-cysteine are the natural precursors of a wide variety of VSCs. Methanethiol is the most frequently found VSC in cheese and can be readily oxidised to other VSCs, such as dimethyl suMde and dimethyl disulfide, or... 

The taste of cheese is concentrated in the water-soluble fraction (peptides, amino acids, organic acids, amines, NaCl) while the aroma is mainly in the volatile fraction. Initially, it was believed that cheese flavour was due to one... 

Nice huh But most likely wrong. The same text does not fail to mention the so-called cheese reaction , which consists in a sudden rise of blood pressure in patients receiving MAO inhibitors. Cheese - as well as other t5q)es of fermented food, such as salami or summer sausage - is rich in decarboxylation products of amino acids (amines), which are in part responsible for the characteristic flavours. The one of interest here is indeed tyramine. Tyramine acts as an indirect S5mipathomimetic , much in the same way as amphetamine does. It can hardly be held responsible for lowering and increasing the blood pressure at the same... 

Figure 3.16 shows that it is possible to employ an additional fermentation with typical starter cultures following the lipolytic reaction and in this example manufacture a roquefort flavour [8]. The additional application of lipaseesterases for the formation of typical ageing notes in cheese flavour is possible. In addition, amino acid catabo-... 

Yvon, M., and Rijnen, L. 2001. Cheese flavour formation by amino acid catabolism. Int. Dairy J. 11 185-201. 

Visser, F. M. W. (1977c). Contribution of enzymes from rennet, starter baaeria and milk to proteolysis and flavour development in Gouda cheese. 3. Protein breakdown analysis of the soluble nitrogen and amino acid fractions, Neth. Milk Dairy J. 31,210-239. 

Proteolysis in cheese has been linked to its importance for texture, taste and flavour development during ripening. Changes of the cheese texture occur owing to the breakdown of the protein network. Proteolysis contributes directly to taste and flavour by the formation of peptides and free amino acids, as well as by Uberation of substrates for further catabolic changes and, thereby, formation of volatile flavour compounds. Besides sensory quality aspects of proteolysis, formation of bioactive peptides as a... 

Proteolytic enzymes. Proteolytic enzymes produced by starter organisms usually play a key role in the degradation of milk caseins to oligopeptides, smaller peptides and amino acids in fermented dairy products and cheese. Besides being necessary for normal growth of lactococci in milk, this degradation of proteins is important for the development of flavour and texture in cheese. 

Free amino acids are only found in small amounts in most foods. Therefore, they only influence the flavour of foods when production is based on proteolysis (some cheeses, but also meat and fish). Enzymatic hydrolysates of proteins (such as soy sauces) or hydrolysed vegetable proteins (add hydrolysates), which contain only amino acids, are used extensively as seasonings. 

For example, intense proteolyses of muscle proteins, due to the action of endogenous proteolytic enzymes, have been reported to occur during the processing of dry-cured ham. This gives rise to the formation of free amino acids and short peptides (especially from actin through the action of cathepsin D in meat and from caseines as a result of plasmin and other proteases in cheeses) that contribute directly or indirectly to the flavour characteristics of the final product. In the case of octapeptide Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala, isolated from beef broth, this reportedly showed umami taste with a threshold value of about 500 mg/1. 

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