## 3 Results and Discussion
### Flavour Analysis of Lamb Patties by E-Tongue  
The PCA analysis shows the contribution rate of the accumulative variance of principal components 1 and 2 (Figure 3). This contribution is greater than >90%, indicating that there \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**Discrimination Power**} \\ \hline
\begin{tabular}{c} Charcoal-grilled \\ Electric barbecue \\ Infrared-grilled \\ Superheated- \\ steam-roasted \\ \end{tabular} & 0.461 & 0.628 * & 0.765 * \\ \hline \end{tabular}
\end{table} 
Table 1: Discrimination analysis of volatile compound profile among the different cooked lamb patty samples using e-nose. is a lot of flavour information. Moreover, there is also high significance (\(p<0.05\)) among the samples cooked by four cooking methods. Infrared grill and superheated steam were located almost in one plot while the charcoal-grilled and electric-barbecue-grilled were located in two different plots. This shows that superheated-steam-roasted and infrared-grilled samples had a significant (\(p<0.05\)) positive correlation with each other. There was a non-significant positive correlation between charcoal-grilled and electric-barbecue-grilled samples. However, there was a significant negative correlation (\(p<0.05\)) between the charcoal-grilled and the superheated-steam-roasted samples. A study by [25], through PCA analysis with a total variance of 90%, showed that the lamb had a significant distribution of volatile compounds contributing to the overall flavour profile with a total variance of 90%. Table 2 shows the response scores of the flavour analysis in the lamb patties. The results of the electric tongue analysis show that all the four cooking methods produced significantly (\(p<0.05\)) different effects on the lamb patties' flavour. The sourness score was highest (8.5) in the superheated-steam-roasted lamb patties. It was lowest (2.9) in the charcoal-grilled patties. There was a significant difference (\(p<0.05\)) in the flavour of these two types of cooked patties. The saltiness was seen to be significantly (\(p<0.05\)) highest in the superheated steam (8.7) while lowest in the charcoal-grilled patties (3.6). Moreover, the umami flavour was also seen to be significantly highest \(p<0.05\)) in the superheated-steam-roasted sample while others had a lower score than this method of cooking. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Cooking Method** & **AHS-Sourness** & **PKS** & **CTS-Saltiness** & **NMS-Umami** & **CPS** & **ANS** & **SCS** \\ \hline Charcoal grill & 2.9 & 8.7 * & 3.6 & 3.1 & 9.0 ** & 8.7 * & 9.0 ** \\ Electric barbecue & 6.0 & 6.3 & 5.0 & 6.0 & 5.9 & 4.0 & 6.1 \\ Infrared grill & 6.6 & 5.7 & 6.7 & 6.4 & 5.4 & 7.2 & 5.4 \\ Superheated steam roast & 8.5 ** & 3.3 & 8.7 ** & 8.6 ** & 3.7 & 4.2 & 3.5 \\ \hline \hline \end{tabular}  
*, ** values within the same column differ significantly (* \(p<0.05\); ** \(p<0.01\)).  
\end{table} 
Table 2: Changes in the responses of electronic tongue sensors in lamb meat patties cooked by four methods. Figure 3: Principal component analysis score projection of e-tongue flavour analysis of charcoal-grilled, electric-barbecue-grilled, infrared-grilled and superheated-steam-roasted lamb patties. The abbreviations indicate CRR for charcoal-grilled, EBR for electric-barbecue-grilled, IR for infrared-grilled and SHR for superheated-steam-roasted. The comparison of the scores of flavour analysis (Table 2) could indicate that the better heat transfers in the superheated-steam oven favoured the formation of flavour compounds (2,3-octanedione and 1-octen-3-ol) compared to the charcoal grill. In addition, those flavour compounds might be related to the stronger sourness, saltiness and umami flavours in the lamb cooked in the superheated-steam oven. However, undesired characteristics have also been associated with 2,3-octanedione formation [20]. Our results of the study are consistent with [47] where all these flavour attributes (sweet, salty, umami and sour) were found in the grilled lamb loin steaks.