## 4 Discussion  
As shown in Table 1, the variations in T1 relaxation times observed with the ICON-1T (MRI) and the LF90 TD-NMR relaxometer reflect the dependence of T1 on magnetic field strength (B\({}_{0}\)), while T2 remains largely unaffected. This behavior aligns with established NMR principles: increasing B\({}_{0}\) raises the energy difference between spin states, which prolongs T1 as spins require more time to return to equilibrium with the surrounding lattice. In contrast, T2 relaxation is primarily influenced by molecular dephasing interactions rather than by energy state transitions, leading to a relative stability of T2 values across different magnetic fields [22]. Additionally, the IV calculated from the \({}^{1}\)H-NMR spectra was consistent with the expected values for each of the oils studied, and these values fall within the limits established in the literature [23]. The strong relationship between the T1 and T2 relaxation times and the IV of the analyzed commercial oils underscores the effectiveness of relaxation techniques in determining the IV, highlighting the sensitivity of these methods for assessing oil composition based on molecular dynamics. Moreover, as shown in Table 1, the TD-NMR method revealed significant differences (\(p<0.05\)) in both T1 and T2 values across all oils analyzed, reinforcing TD-NMR's capacity to distinguish oils based on relaxation profiles and its potential for IV determination. Our results are consistent with recent studies using TD-NMR to differentiate various types of edible olive oils based on relaxation times (T1 and T2) [24]. This alignment underscores the potential of TD-NMR as a reliable method for distinguishing oils by their molecular composition and quality. Consistent with our initial hypothesis, olive oil--predominantly monounsaturated --exhibited the lowest IV and the shortest T1 and T2 relaxation times in both MRI and TD-NMR analyses. In contrast, linseed oil showed the highest IV and longest relaxation times due to its primarily polyunsaturated profile. This pattern highlights a positive correlation between unsaturation levels, IV, and relaxation times, reflecting the oils' distinct molecular structures. The sensitivity of relaxation times to unsaturated fatty acids results from increased molecular mobility and reduced proton-proton interactions, extending relaxation times [25]. To the authors' knowledge, this study represents the first application of MRI and TD-NMR/MRI techniques for the determination of the iodine value (IV) of edible oils. Previous work by [PERSON] et al. [20] established the utility of \({}^{1}\)H-NMR spectroscopy for IV determination, providing a valuable foundation for our study. Recently, [PERSON] and [PERSON] [14] utilized HPLC for IV determination, reporting results comparable to those obtained here. Additionally, ATR-FTIR has been applied successfully to determine the IV in edible oils, achieving high-accuracy regression models (R\({}^{2}>0.98\)) [26]. Both ATR-FTIR and NMR methods are non-destructive techniques for analyzing samples. However, NMR provides the additional advantage of enabling direct analysis within the original packaging, eliminating the need for sample preparation. This unique feature significantly accelerates the data acquisition process, making NMR particularly suitable for rapid and efficient industrial applications. Regression models developed from both the T1 and T2 relaxation times obtained through MRI and TD-NMR, alongside the IV values determined by NMR spectroscopy, reveal significant differences between the oils analyzed. Both relaxation times (T1 and T2) show strong correlations with the IV. Notably, T2 relaxation times can be measured more quickly than T1, making T2 a more efficient metric for routine analysis. In this regard, TD-NMR offers a significant time advantage, with sample analysis taking less than two minutes, whereas MRI typically requires around ten minutes for multiple samples.