Abstract:Due to the mechanical harvesting, about 10%~20% of the harvested tomatoes which did not reach the required maturity of product processing such as tomato paste would be screened out and discarded, resulting in a waste of resources. In order to make rational use of these resources, their quality characteristics were systematically studied. Four processing cultivars, i.e., IVF3535, 8210, Jinfan-11 and 3311, were selected to investigate the quality changes related to flavor and nutrition during four ripening stages, including mature green stage, turning stage, firm ripe stage and ripe stage. The results showed that the dry matter of four processed tomatoes decreased at first and then increased during ripening, while the soluble solid and soluble sugar contents showed insignificant changes. And among them, IVF3535 was superior to the other three cultivars in dry matter, soluble solid and soluble sugar contents. The contents of lycopene, phytofluene, phytoene and β-carotene increased significantly during ripening and have accumulated at the turning stage, while the titratable acid and tomatine decreased significantly, and there was insignificant difference between the mass fraction of tomatine after the turning stage and that at the ripening stage (P>0.05). Therefore, the discarded tomatoes in turning and post-turning stages were qualified to be reused. This study could provide a reference for the efficient utilization of immature tomatoes in the tomato processing industry.