The nutritional quality and antioxidant activity of organic and conventional green beans were compared in a series of experiments. Firmness, percent dry matter, carotenoids and chlorophyll contents, respiration rate, vitamin C and proteins were evaluated. Hydroxyl radical scavenging activity, SOD, APX and POX were also analysed. In a second experiment, organic green beans treated with hexanal formulations were stored with untreated at 12⁰C in the refrigerator for a period of three weeks during two seasons. The results of the experiment showed higher levels of most of the parameters measured in organic green beans (with significant differences in firmness, carotenoids and chlorophyll b), except for respiration, vitamin C, antioxidant activity(hydroxyl radical scavenging) and APX where conventional green beans were higher and showed significant differences in respiration and vitamin C. The storage experiment showed a decrease in firmness and fresh weight and increase in respiration during storage for both seasons. Carotenoids and chlorophyll contents showed decrease in concentrations during the first week and increased during the second week of storage.