Biosynthesis of phenolic antioxidants in carrot tissue increases with wounding intensity

摘要

Biosynthesis of phenolic antioxidants in three carrots cultivars (Navajo, Legend and Choctaw) were studied under different wounding intensities (A/W) during storage. Generated A/W of 4.2,6.0 and 23.5 cm~2/g, corresponded to slices, pies, and shreds, respectively. Soluble phenolics, antioxidant capacity (AOX), and PAL activity increased with A/W for all cultivars. Intense wounding (23.5 cm~2/g) induced an ~2.5- and ~12.4-fold increase in soluble phenolics and AOX, respectively, after 4 days compared to whole carrots. Wounding induced the synthesis of mainly chlorogenic acid (5-CQA) and 3,5-dicaffeoylquinic acid. A higher proportion of 5-CQA in the phenolic mixture was responsible for an increasing specific AOX (809 and 1619 ug Trolox/mg phenolics for whole carrots and shreds, respectively, for Choctaw cultivar). Wounded carrots can be promoted as an inexpensive rich source of phenolic antioxidants for the regular diet. By simply increasing wounding stress intensity it is possible to enhance the biosynthesis of phenolic antioxidants.