## 3 Results and Discussion
### Aromas of Californian-Style Black Olives Stuffed with Hydrocolloids
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**RT**} & \multicolumn{2}{c}{**DPP Classification**} \\  & **(min)** & **Extra** & **Select** & **Standard** \\ \hline
2,4-Dimethylhexane & 6.7 & 0.5 \(\pm\) 0.0 & 2.7 \(\pm\) 0.5 & 4.8 \(\pm\) 0.1 \\
3-Methylpyridine & 10.0 & n.d. & 2.6 \(\pm\) 0.6 & 6.1 \(\pm\) 0.2 \\ \(p\)-Xylene & 10.2 & 5.1 \(\pm\) 0.1 & 3.7 \(\pm\) 2.4 & 1.7 \(\pm\) 0.2 \\ Styrene & 11.3 & 5.3 \(\pm\) 0.3 & 4.1 \(\pm\) 0.4 & 3.3 \(\pm\) 0.3 \\ Benzaldehyde & 15.3 & 2.5 \(\pm\) 0.4 & 12.8 \(\pm\) 2.0 & 21.0 \(\pm\) 2.5 \\ Beta-pinene & 15.5 & 9.4 \(\pm\) 0.5 & 7.2 \(\pm\) 1.5 & 5.0 \(\pm\) 0.8 \\
4-Ethenylpyridine & 15.6 & 1.6 \(\pm\) 0.1 & 6.7 \(\pm\) 1.2 & 13.3 \(\pm\) 0.4 \\
3-Hexen-1-ol, acetate & 17.5 & 3.9 \(\pm\) 0.4 & 2.5 \(\pm\) 0.2 & 1.8 \(\pm\) 0.4 \\ Acetic acid, hexyl ester & 17.9 & 2.2 \(\pm\) 0.2 & 1.9 \(\pm\) 0.2 & 1.3 \(\pm\) 0.2 \\ \(p\)-Cymene & 18.1 & 10.3 \(\pm\) 0.6 & 7.9 \(\pm\) 0.3 & 6.1 \(\pm\) 0.1 \\ Gamma-terpinene & 19.9 & 11.6 \(\pm\) 0.4 & 10.3 \(\pm\) 0.2 & 7.1 \(\pm\) 0.2 \\ Diallyl disulphide & 21.1 & 12.1 \(\pm\) 0.3 & 6.5 \(\pm\) 0.4 & 2.5 \(\pm\) 0.4 \\ Octan-1-ol & 21.2 & 1.7 \(\pm\) 0.5 & n.d. & n.d. \\ Beta-farnesene & 23.1 & 1.6 \(\pm\) 0.1 & 2.6 \(\pm\) 0.1 & 5.8 \(\pm\) 0.1 \\ Cyclohexancerboxylic acid, ethyl ester & 24.1 & 6.6 \(\pm\) 1.2 & 4.8 \(\pm\) 1.3 & 4.1 \(\pm\) 1.2 \\ Creosol & 27.2 & 19.2 \(\pm\) 0.8 & 18.4 \(\pm\) 2.3 & 12.5 \(\pm\) 1.1 \\ Copaene & 35.3 & 6.5 \(\pm\) 1.1 & 5.3 \(\pm\) 0.4 & 3.7 \(\pm\) 1.1 \\ \hline \hline \end{tabular} RT, retention time; n.d., not detected.  
\end{table} 
Table 5: Relative contents of volatile compounds (mean % (\(n=3\))) obtained from Californian-style black olives stuffed with hydrocolloids submitted to different sterilisation treatments. bitter almond. 4-Ethenylpyridine was also quite common in these samples (13.3%), with a pungent and unpleasant odour [22]. 3-Methyl-pyridine (6.1%) contributed an aroma of earth and hazelnut, sweet and not unpleasant [39]. Beta-farnesene (5.8%) has a woody, citrusy and herbal aroma and is sweet to the nose [40]. Finally, 2,4-dimethylhexane (4.8%) was also present, although in small proportions, and it has an unpleasant odour [22]. Finally, it should be noted that some compounds were directly related to the higher quality olives, increasing their concentrations progressively in the select and extra quality olives. Among these compounds were creosol, diallyl disulphide, gamma-terpinene, \(p\)-cymene and beta-pinene, results that agree with those obtained by [PERSON] et al. [9] in their study on table olives, these being the main volatile components in samples without defects. In contrast, compounds such as benzaldehyde, 4-ethenylpyridine, 3-methyl-pyridine and beta-farnesene were more abundant the lower quality samples. It should be noted that octan-1-ol only appeared in the extra quality samples, although in a very low concentration, while 3-methylpyridine was not detected in samples of the highest commercial quality. 4-Ethenylpyridine, benzaldehyde and 2,4-dimethylhexane had great influences after the application of heat treatment, increasing in content. These volatile compounds have unpleasant odour descriptors [22]. In addition, the compounds responsible for other fruit aromas, such as ethyl ester cyclohexanecarboxylic acid and creosol, decreased in content. These results agree with the variations in the VOCs observed in the samples of different qualities, since higher proportions of these unpleasant compounds were found in the samples of lower quality. Similarly, [PERSON] et al. [41], when comparing defects in healthy and defective green olives from Zapateria, found similar VOCs to those identified in this study. The aromas of these compounds were associated with fresh fruit, citrus, herbs and green onions. These results agree with those observed here, since all of them appeared in higher proportions in the higher quality samples. [PERSON] et al.