Nondestructive assessment of ripeness in kiwifruit with near-infrared pulse illumination

We investigate the ripeness of kiwifruit nondestructively with near-infrared pulse illumination. With this measurements in time domain, only one frequency (the wavelength 800 nm is required. Measurements were performed on three golden kiwifruits over a period of ten days. To quantify changes in temporal profiles of the detected light, we introduce two indices: the relative ripeness $r(n)$ and the first Wasserstein distance $W_1(n)$. Both indices exhibit nonmonotonic behavior.