Sensory and Nutritional Quality of First and Second Cuts of Wild Rocket Leaves (Diplotaxis tenuifolia) at the Beginning and the End of Shelf-Life

The widespread practice of multiple harvests is known to significantly affect the quality of rocket leaves. Thus, ready-to-eat wild rocket (Diplotaxis tenuifolia L.) was produced under commercial conditions using leaves from five different varieties, harvested at both the first and the second cut, with a 21-day interval between cuts. Both the sensory and nutritional quality of rocket leaves were evaluated one day after packaging (beginning of shelf-life) and after an additional six days of storage at 6 °C (end of shelf-life). At the beginning of the shelf-life, first-cut leaves generally exhibited a more intense flavor, corresponding to a higher level of isothiocyanates, compared to second-cut leaves. At the end of shelf-life, first-cut leaves showed a greater susceptibility to off-flavor development, corresponding to the release of higher levels of sulfur compounds within the packages. First-cut leaves showed higher content of ascorbic acid and folate with respect of second-cut leaves, both at the beginning and the end of the shelf-life. The commonly held assumption that successive cuts yield leaves with more intense flavor compared to the first cut does not appear to be confirmed. It is likely that the differences in quality observed between leaves from the first and second cuts are not attributable solely to the cutting process or to the sequence of multiple harvest per se, but rather to significant variations in environmental conditions, particularly temperature and light, during the leaf growth period between the two harvests.