Figure 1.

(a) The NMR pulse sequence used for recording relaxation fingerprints. (b) The procedure for generating relaxation fingerprints: (i). NMR relaxation data of a specific vegetable oil sample, which represents the signal intensity f(τ₁, n) acquired using the pulse sequence in (a); (ii). reference relaxation data f_ref(τ₁, n), which is a curved surface obtained by fitting the average relaxation data of six different vegetable oil samples; (iii). heat map plot of the relaxation fingerprints F(τ₁, n) = f(τ₁, n) − f_ref(τ₁, n).