# Characterization of Quality Properties in Spoiled Mianning Ham
## 3 Results and Discussion
### Flavor Compound Analysis  
The types and contents of volatile compounds in normal and spoiled Minanning ham are shown in Table 4, and a total of 94 volatile flavor substances were detected. A total of 57 flavor substances were detected in deeply spoiled ham, including 11 aldehydes, 2 ketones, 6 alcohols, 9 esters, 20 hydrocarbons, 6 acids and 2 other compounds. Meanwhile, 51 flavor substances were detected in surface spoiled ham, including 7 aldehydes, 6 alcohols, 9 esters, 25 hydrocarbons, and 4 acids. Finally, 42 flavor substances were detected in normal ham, including 8 aldehydes, 3 ketones, 5 alcohols, 3 esters, 19 hydrocarbons, and 4 acids. More volatile compounds were found in deeply spoiled ham than in surface spoiled ham. Hexanal (279.607 \(\pm\) 127.265 \(\upmu\)g/kg) had the highest content in deeply spoiled ham, followed by Butanoic acid (266.885 \(\pm\) 55.439 \(\upmu\)g/kg) and Nonanal (165.079 \(\pm\) 63.923 \(\upmu\)g/kg). As recently shown, 3-methyl-butanal was one of the largest contributors to the flavor of Istrian dry-cured hams [41]. The most abundant aldehyde in the hams was hexanal generated by lipid oxidation. It was particularly high in Sanchuan ham at 6.52%, which revealed that the oxidation extent of Sanchuan ham was higher than Minanning ham [42]. Hexanal content has been widely used to monitor oxidative stability in meat and meat products [43]. Benzeneacetaldehyde (251.58 \(\pm\) 19.643 \(\upmu\)g/kg) had the highest content in surface spoiled ham, followed by butanoic acid (226.173 \(\pm\) 90.197 \(\upmu\)g/kg) and benzaldehyde (251.58 \(\pm\) 19.643 \(\upmu\)g/kg). Phenylacetaldehyde, another Strecker aldehyde, provided hams with a honey-like odor [19]. Normal ham had the least variety in volatile compounds, the highest of which was hexanal (169.272 \(\pm\) 2.965 \(\upmu\)g/kg), followed by nonanal (99.869 \(\pm\) 14.441 \(\upmu\)g/kg) and benzaldehyde (96.138 \(\pm\) 1.627 \(\upmu\)g/kg). Acids were present in a lower amount in all the hams: 8.36% in Minanning ham, 7.15% in Nuodeng ham, 3.18% in Saba ham, and 2.35% in Sanchuan ham. Amongst these compounds, the most abundant acids were 3-methyl-butanoic acid, followed by acetic acid, 2-methyl-propanoic acid, and butanoic acid [41]. Figure 4: Relative abundance of fungal community proportions at the phylum (**a**) and genus (**b**) levels in Minanning ham. Different colors represent different fungal community and the size of the color area represents the relative abundance (percentage) of fungal community at the phylum (**a**) and genus (**b**). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Number** & **RT** & **Compound Name** & **CAS** & \multicolumn{3}{c}{**Absolute Content (ug/kg)**} \\ \hline  & & & & **FBS** & **FBQ** & **ZC** \\ \hline   Aldehydes & & & & & & \\  1 & 4.999 & Heural & & & & \\  2 & 10.594 & Heural & & & & \\  3 & 11.014 & Mehioni & & & & \\  4 & 16.376 & Benzaldehyde & & & & \\  5 & 23.802 & Benzacetaldehyde & & & & \\  6 & 25.084 & & & & & \\  7 & 28.103 & Nonanal & & & & \\  8 & 31.274 & & & & & \\  9 & 30.769 & Decantal & & & & \\  10 & 36.52 & & & & & \\  11 & 58.302 & Pentadecanal & & & & \\  12 & 58.307 & Hexadecanal & & & & \\   Ketones & & & & & \\  13 & 9.836 & & 2-Hepntanone & & & \\  14 & 9.848 & & 5-Methyl-2-hexanone & & & \\  15 & 27.433 & & 2-Nonanone & & & \\  16 & 8.874 & & 11-Hexenol & & & \\  17 & 18.451 & & 11-Hepntanol & & & \\  18 & 19.052 & & 1-Octen-3-d & & & \\  19 & 23.341 & & 2-ethyl-1-Hexenol & & & \\  20 & 23.341 & & & & \\  21 & 23.347 & & 1-pentanol & & & \\  22 & 26.098 & & 2-Dretal & & & \\  23 & 26.104 & & & & \\  24 & 26.11 & trans-2-Chloroned-1-d & & & & \\  25 & 28.68 & & 2-butyl-1-Octanol & & & \\  26 & 31.268 & & 2-ethyl-1-Decanol & & & \\   Eswer & & & & & \\  27 & 16.423 & & 1-(benzoyl)2,5-Pybridindindindence & & & & \\  28 & 22.444 & & 3-7-dimethyl-1-d-C-d-3-d & & & \\  29 & 24.466 & Butyl isovalerate & & & \\  30 & 25.061 & & & & \\  & & & & & \\ \hline  & & & & & \\ \end{tabular}
\end{table} 
Table 4: Types and contents of flavor compounds in Manning ham.