Nutritional Composition, Bioactive Components and Antioxidant Activity of Garden Cress (<i>Lepidium sativum</i> L.) Grown Under Deficit Irrigation

This study examined how different water restriction levels (T100%, T85%, T75%, and T55%) influence the nutritional and bioactive compounds of Bahar and Dadaş cress (<i>Lepidium sativum</i> L.) cultivars. The highest levels of phenolic compounds found in Dadaş and Bahar cress were quercetin (8.33 ± 0.23–9.32 ± 0.25 µg/L), ferulic acid (8.08 ± 0.18–8.42 ± 0.19 µg/L), catechin (6.83 ± 0.28 µg/L), and caftaric acid (5.40 ± 0.45 µg/L). Mild and moderate drought treatments (85% and 75% humidity) caused notable increases in phenolic compounds. The highest antioxidant enzyme levels were observed as GST, 6GPD, and G6PD in Bahar and Dadaş cress, with enzyme levels rising under drought conditions. Notably, the mild drought treatment roughly doubled peonidin-3-glucoside acetyl levels in the cress cultivars. Sugar contents of Dadaş and Bahar cress cultivars also rose significantly with drought treatment. Riboflavin, the most abundant vitamin in cress cultivars, increased to 40.96 ± 1.24 mg/kg in Dadaş and 30.79 ± 1.60 mg/kg in Bahar cress under drought stress. Amino acids showed the highest increases under severe drought, with asparagine rising by roughly 2.76-fold and leucine increasing by 2.67-fold in Bahar cress. These findings suggest that controlled water restriction can enhance the nutritional and bioactive properties of cress, potentially leading to more nutrient-rich products for the food industry and human health.