Phenolic compounds and antioxidant power in minimally processed salad

Phenolic content and antioxidant power of Lactuca sativa var. capitata (L.), Cichorium indivia var. latifolium (L.) and Eruca sativa (Mill.) were determined in fresh-cut products during storage at 4C. In fresh-cut leaves, storage did not affect the antioxidant power in escarole, whereas after 24 h, lettuce exhibited a transient rise in ferric-reducing antioxidant power value (+50%), which was associated with increased phenol content. In rocket salad, the antioxidant power increased significantly just 1 h after cutting. The major phenols determined in escarole and lettuce hydroxycinnamic derivatives were chlorogenic acid, di-caffeoylquinic and caffeoyltartaric acids, which increased significantly in fresh-cut products of both species during storage. In rocket salad, only hydroxycinnamic and kaempferol derivates were found, and their content was not influenced by processing and storage even if it is probably related to the higher antioxidant power found for this species.