## 3 Results and Discussion
### Pattern of Volatile Compounds of the Specific Odors Using PLS
The branched aldehyde, 2-methyl propanal, was the only volatile compound found in common with this study. Compounds negatively related to this odor were styrene (balsamic, gasoline), 3-carene (lemon, resin), hexan-2-enal (apple, green), 2-methylfuran (chocolate), and some alkanes such as octane and pentane (alkene odor, both). These compounds belong to the alkanes and terpen, and some authors have noted that these groups of volatile compounds are unlikely to contribute to flavor, due to the fact that they have a high threshold [53; 60]. Nevertheless, these negatively related compounds also had an impact on vinegar odor, so their presence is probably only the result of creating a synergism, suppression, or increase in other important volatile compounds that are part of the pattern of compounds [38]. Rancid odor was positively related to butanal (pungent), non-2-enal (toast), oct-2-enal (glue), 2-methyl-butan-1-ol (wine, onion), ethanol (sweet), hexanal (grass, fat), propanoic acid (pungent, rancid), acetic acid (sour), 2-phenylacetaldehyde (sweet, green), and some esters, such as ethyl octanoate (fruit, fat) and ethyl decanoate (grape). This odor was negatively related to 2-ethylhexan-1-ol (green), butan-1-ol (medicine), pentan-2-ol (green, plastic), allylmercaptan (garlic), and \(\alpha\)-terpinene (woody) Figure 3. Other authors have reported the relationship of rancid flavor with non-2-enal, octanol [38], organic acids such as pentanoic and hexanoic acids, 2-pentylfuran, ethyl octanoate [55], and hexanal [15; 38; 44; 55; 60], which is the main volatile compound associated with rancid odor and is strongly related to aroma quality and consumer acceptability [17]. Fermented odor was positively related to non-2-enal (toast), 2-methylbutan-1-ol (wine), ethanol (sweet), propanal (solvent), hexanal (grass, fat), and undecane (alkane), and negatively related to ethyl octanoate (fruit, fat), methyl octanoate (orange), 2-methylfuran  
Figure 3: Standardized coefficients of volatile compounds used to predict odors: rancid (**A**), fermented (**B**), vinegar (**C**), and pork meat (**D**). (chocolate), allyl mercaptan (garlic), and dodecane (alkane), Figure 3. Some compounds, like 2-methylbutan-1-ol, butanoic acid, pentanoic acid, and ethyl hexanoate, create a fermented odor in cheese [61]. In meat products, [PERSON] et al. [62] found the volatile compounds nonanal, octanal, hexanal, 1-octen-3-ol, heptanol, ethyl hexanoate, ethyl butyrate, ethyl acetate ethyl heptanoate, ethyl octanoate, and methyl hexanoate had an impact on the overall flavor profile of the fermented sausage. Furthermore, [PERSON] et al. [21] found that the esters ethyl 2-methylpropanoate, ethyl-3-methylbutanoate, ethyl butanoate, ethyl pentanoate, and ethyl hexanoate contribute to fermented sausage aroma. Our results also showed that some esters contribute to generating this odor, but indirectly, due to the fact that these had a negative correlation; the presence of esters probably overpowers the fermented odor [57]. Another study found a relationship with 3-methlbutanal, 2-methylbutanal, diacetyll, and 3-methyl butanoic acid [39]. Pork meat odor was positively related to pentane (alkane), 2-methylfuran (chocolate), ethyl propanoate (fruit), heptan-2-one (cheese), and heptan-2-ol (mushroom), and negatively related to 2-methylbuthyl acetate (fruit), ethanol (sweet), ethyl butyrate (apple), heptanoic acid (unpleasant), heptanal (fat, rancid), nonanal (fat, citrus), limonene (citrus), terpinen-4-ol (wood), and undecane (alkane), Figure 3. Furan is the main group of volatile compounds related to meaty flavor, but other authors have found 3-methylfuran, 2-ethylfuran, 2-acetylfuran, and 2-pentyl furan are related to meat odor [21; 55]. These are derived from linolenic acid and other n-6-fatty acids [53]. [PERSON] et al.