Dairy products impact flavor compounds

Table 7 Character Impact Flavor Compounds in Cheese and Dairy Products...

Quantification of FFAs in dairy products, especially in cheese, is particularly important due to the impact of some FFAs on flavor. However, FFAs act as precursors of a wide range of flavor compounds (e.g., methyl ketones, lactones, esters and aldehydes), (Singh et al, 2003). The extent of lipolysis in cheese varies widely between varieties (Table 19.2). Typically, those cheeses with more than 3000 mg/kg have a characteristic lipolytic aroma/flavor and lipolysis plays an important role in their ripening. A major difficulty in quantifying FFAs in cheese is the distribution of FFAs of different chain length within the cheese matrix. SCFFA (C4 o—C8 0) partition mainly into the aqueous phase, whereas medium (Cio q—C14 0) and longer... 

A second dairy product where carbonyls are considered as flavor impact compounds is yogurt. Here acetaldehyde is credited with providing the characteristic pungent, green character. Acetaldehyde is a metabolic end product of L. bulgaricus and/or S. thermophilus during the fermentation of milk to yogurt [84]. 

In recent studies, potent aroma compounds have been identified using various gas chromatography-olfactometry (GCO) techniques, such as Charm Analysis and aroma extract dilution analysis (AEDA) (7,8). The flavor compounds that are identified by these methods are significant contributors to the sensory profile. In some cases, these sensory-directed analytical techniques have enabled the discovery of new character impact compounds. However, in other instances, key aroma chemicals have been identified that, while potent and significant to flavor, do not impart character impact. For example, in dairy products, chocolate, and kiwifmit, these flavor types appear to be produced by a complex blend of noncharacterizing key aroma compounds. 

With a few exceptions, many of the known important flavors in dairy products do not provide characterizing roles. This is especially true for milk, cheddar cheese, and cultured products, such as sour cream and yogurt. Delta-lactones are important flavors in butter, buttermilk, and cheeses that are derived from triglycerides containing hydroxyl fatty acids. Although not directly contributing as dairy character impact compounds, lactones play key supporting roles. The subject of key odor-active compounds in milk dairy flavors has been recently reviewed (76,77). A summary of character impact compounds for cheese and dairy flavors is presented in Table 7. 

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