Thermal Processing and Kinetics

The thermal degradation rate constant of thiamine in liquid milk at $100^\circ\text{C}$ (373 K) is $k_1 = 0.01\text{ min}^{-1}$ and at $120^\circ\text{C}$ (393 K) is $k_2 = 0.04\text{ min}^{-1}$. Given universal gas constant $R = 8.314\text{ J/(mol}\cdot\text{K)}$ and $\ln(4) = 1.3863$, the activation energy $E_a$ in kJ/mol using Arrhenius equation $\ln(k_2/k_1) = \frac{E_a}{R}\left(\frac{1}{T_1} - \frac{1}{T_2}\right)$ with $\left(\frac{1}{373} - \frac{1}{393}\right) = \frac{20}{146589} = 1.3643 \times 10^{-4}\text{ K}^{-1}$ is: