Table 4 also indicates that both types of lettuces can be analyzed using specific or global models. This point is crucial because that demonstrates that a global model can be used for different vegetables that exhibit similar UV shapes. It means that it is not necessary to create specific models relative to each vegetable , or even each season or producer.Finally, result in Table 4 also demonstrate that the uncertainties of the estimated value were quite low,and at least in the uncertainty range of the reference methods.