## 2 Results and Discussion
### Odor-Active Compounds Identification  
To understand which specific compounds are responsible for the characteristic aroma of meads and what makes a product attractive to consumers, a screening for odor-active compounds was performed. In the first stage of the research, all twelve safe extracts were subjected to GC-O analysis. The application of GC-O analyses showed a total of 23 odor-active compounds in twelve tested mead samples. All identified odor-active compounds are listed in Table 1, and they are consistent with those obtained in our previous study [13]. 2- and 3-Methyl-1-butanol (malty), 2- and 3-methylbutan-1-ol (malty, solvent-like), ethyl octanoate (fruity), acetic acid (vinegar-like), 3-(methylsulfonyl)propanal (cooked potatoes-like), propanoic acid (sour, sweaty), butanoic acid (sweaty), 2-phenylacetaldehyde (honey-like), 2- and 3-methylbutanoic acid (malty, solvent-like), 2-phenylathan-1-ol (floral), 4-methylphenol (horse stable-like), phenylacetic acid (honey-like, beeswax-like), and 4-hydroxy-3-methoxybenzaldehyde (vanilla-like) were identified in all tested mead samples. Ethyl hexanoate (fruity, pineapple-like) was identified in only two mead samples undergoing spontaneous fermentation: ANS and BNS. 1-(3,4-Dihydro-2H-pyrrol-5-yl)ethan-1-one(roast-like) was found in only one sample (ANS). Among identified compounds, aldehydes 2- and 3-methyl-1-butanal (malty), 3-(methylsulfonyl)propanal (cooked potatoes-like),furan-2-carbaldehyde(sweet, cereal-like), 2-phenylacetaldehyde (honey-like), and 4-hydroxy-3-methoxybenzaldehyde (vanilla-like) were the biggest group together with the acids acetic acid (vinegar-like), propanoic acid (sour, sweaty), butanoic acid (sweaty), 2- and 3-methylbutanoic acid (malty, sweaty), and phenylacetic acid (beeswax-like). The third largest group was esters, ethyl pentanoate (fruity), ethyl hexanoate (fruity, pineapple-like), and ethyl octanoate (fruity), together with alcohols: 2- and 3-methylbutan-1-ol (malty, solvent-like), 3-(methylsulfonyl)propan-1-ol (cooked potatoes-like), and 2-phenylathan-1-ol (floral). Two compounds, 3-(methylsulfonyl)propan-1-ol (cooked potatoes-like) and (2_E_)-1-(2,6,6-trimethylcyclohexa-1,3-dien-1-yl)but-2-en-1-one (cooked apple-like), were identified only in meads prepared from acacia honey, in all fermentation types. 4-Methylquinazoline, an odorant with a characteristic mint-like odor was identified in all fermentation samples made from buckwheat and cilia honey but was absent in all samples prepared using acacia honey. This compound was also detected in our previous research on mead made from multifiloral honey, where its concentration was highest in the honey sample, suggesting that honey may be its source [13]. The results of this study indicate that acacia honey, unlike buckwheat and cilia honey, does not contain this odor-active compound. Additionally, 3-hydroxy-4,5-dimethylfuran-2(5_H_)-one, which has a fenugreek-like odor, was identified exclusively in three samples made from buckwheat honey: BNS, BNSM, and BNY. Sweet furan-2-carbaldehyde was identified in all samples prepared from cilia honey and one sample made from buckwheat honey: BNS.  
Figure 1: Quantitative olfactory profile analysis of acacia-based meads.  
Figure 3: Quantitative olfactory profile analysis of cilia-based meads.  
Figure 2: Quantitative olfactory profile analysis of buckwheat-based meads.