Key Odorants Forming Aroma of Polish Mead: Influence of the Raw Material and Manufacturing Processes

Mead was analyzed by using the concept of molecular sensory science for the identification of key odorants. A total of 29 odor-active compounds were identified in mead by using gas chromatography olfactometry (GCO). Flavor dilution (FD) factors of identified compounds ranged from 1 to 16,384, compounds with FD factors ≥32 were quantitated by using stable isotopically substituted odorants as internal standards or external standard method, and odor activity values (OAVs) were calculated. Fifteen compounds showed OAVs ≥1: aldehydes (2-phenylacetaldehyde, 3-(methylsulfanyl)propanal), 4-hydroxy-3-methoxybenzaldehyde), esters (ethyl 3-methylbutanoate, ethyl propanoate, ethyl octanoate), alcohols (2-phenylethan-1-ol, 3- and 2-methylbutan-1-ol, 3-(methylsulyfanyl)propan-1-ol), furanons (4-hydroxy-2,5-dimethylfuran-3(2H)-one, 3-hydroxy-4,5-dimethylfuran-2(5H)-one), acids (3- and 2-methylbutanoic acid, acetic acid), 1,1-diethoxyethane, and 4-methylphenol. 2-Phenylacetaldehyde (OAV, 3100) was suggested as the compound with the biggest influence on the aroma of mead, followed by 4-hydroxy-2,5-dimethylfuran-3(2H)-one (OAV, 1900), 3-(methylsulfanyl)propanal (OAV, 890), and 2-phenylethan-1-ol (OAV, 680). Quantitative olfactory profile analysis revealed strong honey, malty, and alcoholic impressions. Omission experiments revealed that 3-(methylsulfanyl)propanal, 2-phenylethan-1-ol, 4-hydroxy-2,5-dimethylfuran-3(2H)-one, ethyl propanoate, ethyl 3-methylbutanoate, 2-phenylacetaldehyde, 3- and 2-methylbutanoic acid, 3-hydroxy-4,5-dimethylfuran-2(5H)-one, and 4-hydroxy-3-methoxybenzaldehyde were the key odorants in the mead. Determining concentrations of key odorants in important production steps showed that the fermentation and maturation stages had the strongest effect on the formation of mead aroma.