Butter aroma substance

Cheese flavor. C. f. is formed from milk fat, milk protein, lactose during the maturation of cheese mainly through enzymatic and microbial processes. Quantitative and, sometimes, qualitative differences are responsible for the diversity of cheese flavors. Typical aroma substances are the free C4-C,2 fatty acids, C7, C and C, 2-alkanones (also in Roquefort cheese), the butter aroma substances acetoin, 2,3-butanedione, and 5- alkanolides, (-)-(R)-l-octen-3-ol (fungus note in Camembert), 4-alkanolides and alkylpyrazines with nut-like nuances, indole, skatole, and phenols with stable-like odors, as well as numerous sulfur compounds such as methional, methyl mercaptan (moldy, coal-like), dimethyl sulfide and dialkyl polysulfides with, in part, onion- and garlic-like nuances. Furaneol" and homofuraneol (see hydroxyfura-nones) are responsible for the sweetish odor of Em-mental cheese. 

Numerous lactones are found in food. Some of the representatives which belong to the typical aroma substances of butter, coconut oil, and various fruits are presented in Table 5.31. 

In the AEDA of UHT milk (Table 10.38), 5-decalactone, which contributes to the aroma of butter (Table 10.40) as well as unripened and ripened cheese (cf. 10.3.5), is the predominant aroma substance. Apart from other lactones, 2-acetyl-l-pyrroline, methional, 2-acetyl-2-thio-azoline and 4,5-epoxy-2-decenal are among the identified aroma substances. 

Table 10.40. Concentrations of the key aroma substances in five samples of butter ...

The butter-like note of unripened cheese can still be detected in Camembert and Emmentaler, but the intensity is lower, because other aroma substances formed during ripening become evident. Thus, Camembert also has mushroom-like, sulfurous and flowery notes and Emmentaler, nutty, sweet and fruity notes. In comparison with unripened cheese, the taste profile is extended to include a glutamate note and in the case of Emmentaler, an additional and characteristic sour/pungent impression. 

The chemical transformations of wine by malolactic fermentation are much more complex in reality. Malolactic fermentation also produces ethyl lactate, the formation of which conffibutes to the sensation of body in wine (Henick-Kling, 1992). Additionally, other secondary products have been identified, the most important being diacetyl, produced by bacteria (a few milligrams per liter), that belongs to a complex pool of production and degradation mechanisms. At moderate concentrations, this secondary product contributes to aromatic complexity, but above 4 mg/1 the characteristic butter aroma of this substance dominates. 

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