D0 = Intercept coefficient; D1 = slope coefficient; Err[Di] = standard error of coefficient ‘Di’; p -value = probability Di ≠ 0 (< 0.05). See Tables 1-3 for abbreviations.
coefficients (D0) that were very low (between −0.3 and +0.3) and ANOVA indicated they were not significant (p -value > 0.05) allowing D0 = 0 to be assumed. The slope coefficients (D1) were significant (p -value << 0.05) with values for four of the FAME being close to unity (0.996-1.05) indicating good confirmation of these model equations. Similar to the results for Model A , theModel B confirmation equation for MeC18:2 yielded the lowest D1 coefficient (0.93), suggesting that its model equation under predicted IPB, with respect to experimental IPR values. This was confirmed for four of the six data pairs evaluated for MeC18:2, where IPR> IPB at the same four temperatures (50, 60, 90 and 100 °C [323.15, 333.15, 363.15 and 373.15 K]) as observed above for its Model A equation.
The MAD and RMSD results calculated from (IPR, IPB) data pairs are presented in Table 5 . Similar to the results for Model A , the confirmation results for Model B exhibited generally low values, MAD = 0.081-0.61 and RMSD = 0.12-0.86. MeC18:2 had the highest MAD and RMSD values, suggesting its predicted IPB values were influenced by the lower D1 coefficient in its confirmation equation.
The results for the residuals (IPR − IPB) calculated from application of the Model Btype equations to the data for the five FAME are presented inFigure 3 . Overlayed with these results are residuals (IPR − IPA) obtained from theModel A equations (discussed earlier). In general, the residuals for Model B were ≤ 1.47 for all 26 data pairs with 21 data pairs having residuals ≤ 0.44. The highest residual (1.47) was for MeC18:1 at T = 100 °C (373.15 K). Summarizing the Model Bresults, the application of this type of model equation to IPR-T−1 data did an excellent job predicting IPB values within the range of measurement temperatures corresponding to the five FAME studied in the present work.
Direct comparison of results from applying Model A andModel B type equations to IPR data for the five FAME showed that the calculation of IPB values from theModel B equations yielded more accurate results. This is best demonstrated by the deviation results obtained from confirmation analyses performed on both models. First, comparing the data plotted inFigures 2 and 5 shows that IPA data points tended to be more separated from the dashed line than the IPB results, especially when IPR> 15 h. This observation is supported by the residuals data overlayed for Models A and B in Figure 3 . These results demonstrate that residuals were generally larger in the IPA data than the IPB data. Finally, comparing MAD and RMSD data in Tables 3 and 5 shows that values were consistently lower for Model B results for four of the five FAME studied herein. The exception was observed for MeC18:1, where the Model A results yielded MAD = 0.42 and RMSD = 0.62, values that were slightly lower than those for the Model B results (0.61 and 0.86).