## 3 Results and Discussion
### Spectra Overview  
The mean reflectances of the sausage cores with treatments 10 and 19 (as the representatives) are shown in Figure 3. The mean reflectance of the sample with treatment 10 was lower (i.e., higher absorbance) than the sample with treatment 19. Accordingly, the measured average moisture content of the treatment 10 (49.71 \(\pm\) 1.78%) sample was significantly higher than that of treatment 19 (43.47 \(\pm\) 3.50%) (\(p\)! 0.05), indicating sausages stuffed with different casing treatments may have their own feature spectra in the NIR range. The different absorbances recorded by the NIR hyperspectral system are linked  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Coded Coefficients** & & & & \\ \hline
**Term** & **Coefficients** & **SE Coefficients** & \(t\)**-Value** & \(p\)**-Value** \\ \hline Constant & 48.004 & 0.689 & 69.72 & 0 \\
1 SLC & 0.568 & 0.352 & 1.61 & 0.136 \\
2 SOC & 0.467 & 0.352 & 1.33 & 0.212 \\
3 Treated Time & \(-\)0.424 & 0.352 & \(-\)1.2 & 0.254 \\
4 Orange Extracts & 0.228 & 0.352 & 0.65 & 0.532 \\
5 Lactic Acid & \(-\)0.478 & 0.352 & \(-\)1.36 & 0.202 \\ Square & & & & \\
1 SLC2 & \(-\)0.423 & 0.319 & \(-\)1.33 & 0.211 \\
2 SOC2 & 0.296 & 0.319 & 0.93 & 0.372 \\
3 Treated Time2 & 0.258 & 0.319 & 0.81 & 0.435 \\
4 Orange Extracts2 & \(-\)0.418 & 0.319 & \(-\)1.31 & 0.216 \\
5 Lactic Acid2 & \(-\)0.438 & 0.319 & \(-\)1.37 & 0.197 \\
2-way interaction & & & & \\
1 SLC \(\times\) 2 SOC & 1.147 & 0.432 & 2.66 & 0.022 \\
1 SLC \(\times\) 3 Treated Time & \(-\)0.701 & 0.432 & \(-\)1.62 & 0.133 \\
1 SLC \(\times\) 4 Orange Extracts & \(-\)0.253 & 0.432 & \(-\)0.59 & 0.570 \\
1 SLC \(\times\) 5 Lactic Acid & 0.091 & 0.432 & 0.21 & 0.838 \\
2 SOC \(\times\) 3 Treated Time & \(-\)0.597 & 0.432 & \(-\)1.38 & 0.194 \\
2 SOC \(\times\) 4 Orange Extracts & \(-\)0.999 & 0.432 & \(-\)2.31 & 0.041 \\
2 SOC \(\times\) 5 Lactic Acid & 0.832 & 0.432 & 1.93 & 0.080 \\
3 Treated Time \(\times\) 4 Orange Extracts & \(-\)0.308 & 0.432 & \(-\)0.71 & 0.490 \\
3 Treated Time \(\times\) 5 Lactic Acid & 0.344 & 0.432 & 0.8 & 0.443 \\
4 Orange Extracts \(\times\) 5 Lactic Acid & \(-\)0.64 & 0.432 & \(-\)1.48 & 0.166 \\ \hline \hline \end{tabular} Note: 1 SLC: soy lecithin concentration, 2 SOC: soy oil concentration, SE coefficients: standard error of the regression coefficients.  
\end{table}
Table 2: Regression summaries for dependent variables: coefficients in terms of coded factors and fit statics.  
Figure 2: The moisture content of the sausage cores as affected by SLC and SOC (**a**) 3D surface plot; (**c**) 2D contour plot; and affected by SOC and OPE additions (**b**) 3D surface plot; (**d**) 2D contour plot.  
to combinations of fundamental vibrations of functional groups such as C-H, N-H, O-H, and S-H [42], according to internal structural changes or intermolecular force changes. For instance, the slope shape within the 600-700 nm range is consistently indicative of oxymyoglobin formation, whereas the absorption band in transmittance at 790 nm corresponds to the third overtone of N-H stretching combined with protein [43]. Additionally, subtle absorption observed at 780 nm could be associated with the third overtones of O-H stretching, while subtle absorption observed at 980 nm could be pertinent to the second overtones of O-H stretching that relate to water [3]. Lastly, the absorption observed at 940 nm is linked to fat and pertains to the third overtone of C-H [3].