Abstract:Tomatoes are important for human diet due to their content of bioactive compounds. However, is little known about behavior of these compounds during fruit shelf life. The goal of this research was to evaluate the effects on bioactive compounds of tomato fruits stored during different times and conditions, obtained from tomato plants developed under conditions of saline stress and with the application of copper nanoparticles. Four treatments were evaluated: foliar spray of copper nanoparticles (250 mg L −1 ) with or without saline stress, only saline stress, and the absolute control. The results show that application of copper nanoparticles has a positive effect on the accumulation of bioactive compounds such as total phenols, β-carotene, and vitamin C. The saline stress during the development of tomato plants causes a decrease of the bioactive compounds as well as antioxidant capacity in tomato fruits. However, this negative effect can be reduced with the application of copper nanoparticles. The application of copper nanoparticles may be a technique to increase and maintain the content of bioactive compounds in tomato fruits and can be an effective alternative to diminish the negative effects on bioactive compounds caused by saline stress.