Influence of sowing time on phenolic composition of rocket

This paper provides information about the phenolic composition of Eruca vesicaria (L.) Cav. (garden rocket) and Diplotaxis tenuifolia (L.) DC. (wild rocket). Kaempferol, quercetin and isorhamnetin glycosides were found in E. vesicaria. Quercetin and isorhamnetin glycosides were detected in D. tenuifolia. In addition, the latter contained other unidentified phenolic substances. The influence of sowing date on phenolic content was investigated. Two sowing times were evaluated: February-March and July-August. Plants were grown in open-field and harvested about 40 days after sowing. The phenolic content of spring-harvested plants was higher than summer-harvested ones: a difference of 2-3 times in the former and up to 7 times in the latter was noticed. As to flavonoids, harvesting time appears to influence particularly some quercetin and isorhamnetin derivatives found just in trace in summer-harvested plants.