## 3 Results and Discussion
### Oxidation Flavor (OF)  
CDT had an average OF of 2.5 at week 1, 2.5 at week 7, and 2.2 at week 13. There was no difference in OF between antioxidant treated samples and the control. CF with phosphate had an average OF of 1.6 at week 1 and 1.5 at week 7, whereas CF without phosphate had an average OF of 2.0 at week 1 and 1.8 at week 7 with no practical difference between control and antioxidant treated samples. The OF-values for CF with and without phosphate were shown by \(t\)-test to be statistically different (\(p\) < 0.0001). G09 was the most efficient antioxidant in CF concerning reduction in headspace hexanal with 400 mg/kg being the recommended level of addition. Numerically, SE2.5 had 0-0.3-unit lower OF-values than G09 for the same combination of phosphate and storage time, though this difference is so small that it likely has no practical significance. PP with phosphate had an average OF of 1.8 at week 1, 2.2 at week 7, and 2.1 at week 13, whereas PP without phosphate had an average OF of 2.3 at week 1, 2.7 at week 7, and 3.1 at week 13. The OF-values for PP with and without phosphate were shown by \(t\)-test to be statistically different (\(p\) < 0.0001). It should be noted that none of the above-mentioned OF-values were enough to lead to rejection by the sensory panel as the values were even below or just above the level of OF detection of 2-2.5. Similar results were found by [22] when using hexanal as a marker for oxidation in sliced, uncured deli turkey with added RE. Looking at the correlation between headspace hexanal determined by SPME-GC and OF determined by the sensory panel, it turns out that, for CDT, there was a significant effect of week (\(p\) = 0.005), while for CF and PP, there were significant interactions between headspace hexanal and week (\(p\) = 0.038 for CF; \(p\) = 0.016 for PP). Hence, for all three product types, correlation models were built separately for each week. Significance of correlation between headspace hexanal and oxidation flavor for CDT, CF, and PP after 1, 7, and 13 weeks of refrigerated storage is given in Table 4.  
The correlation model for CDT was only good at week 7. The very low headspace hexanal level is likely the cause for this lack of correlation, as the sensory _OF_-values for CDT were on par with those for PP. It was possible to build, statistically speaking, good correlation models for both CF and PP for all the weeks of refrigerated storage studied. The prediction models for CF illustrated in Figure 1 have the following Equations (1) and (2), with the 95% prediction intervals (PI) in parentheses:  
\[\text{Week 1}:\;OF=1.86\times hexanal+1.49\;(\pm 0.54),\;p=0.031,\;R^{2}=0.332 \tag{1}\]  
\[\text{Week 7}:\;OF=0.54\times hexanal+1.21\;(\pm 0.36),\;p=0.001,\;R^{2}=0.649 \tag{2}\]  
The prediction models for PP illustrated in Figure 2 have the following Equations (3)-(5), with the 95% prediction intervals (PI) in parentheses:  
\[\text{Week 1}:\;OF=1.13\times hexanal+1.60\;(\pm 0.79),\;p=0.007,\;R^{2}=0.338 \tag{3}\]  
\[\text{Week 7}:\;OF=0.52\times hexanal+2.05\;(\pm 0.70),\;p=0.001,\;R^{2}=0.468 \tag{4}\]  
\[\text{Week 13}:\;OF=1.11\times hexanal+1.84\;(\pm 0.73),\;p<0.0001,\;R^{2}=0.701 \tag{5}\]  
Figure 1: _Cont._ \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{4}{c}{**Significance of Correlation between Hexanal and Oxidation Flavor**} \\ \hline  & **Week 1** & **Week 7** & **Week 13** \\ \hline CDT & \(p=0.7960\) & \(p=0.0379\) & \(p=0.4269\) \\ CF & \(p=0.0312\) & \(p=0.0005\) & — \\ PP & \(p=0.0071\) & \(p=0.0009\) & \(p<0.0001\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Significance of correlation between headspace hexanal and oxidation flavor for cured deli turkey (CDT), chicken fillet (CF), and pulled pork (PP) after 1, 7, and 13 weeks of refrigerated storage. — indicates that no measurements were done for CF at week 13.