The antioxidative potential of sea grapes (Caulerpa lentillifera, Chlorophyta) can be triggered by light to reach comparable values of pomegranate and other highly nutritious fruits

The interest in edible sea grapes (Caulerpa lentillifera) is increasing due to their potentially beneficial effect on human health. This macroalga, already used for direct and indirect human consumption, is grown in aquacultures in Vietnam and The Philippines. Here, the edible fronds of sea grapes were examined for their antioxidant activity (AOA) at light intensities from 140 to 300 µmol photons m−2 s−1 and compared to commercially dehydrated C. lentillifera and the renowned highly antioxidative fruits Pomegranates (Punica granatum), Goji (Lycium barbarum and L. chinense) and Aronia (Aronia melanocarpa) berries, using an ABTS+-assay for all samples. AOA of fronds exposed to 300 µmol photons m−2 s−1 for 14 days increased by about 320% from the initial value of 72.2 ± 5.6 to 232.2 ± 34.2 Trolox Equivalents (TE) mmol 100 g−1 dry weight (DW) onto the level of Pomegranates (272.8 ± 23.0 TE mmol 100 g−1 DW). This application could be used as a post-cultivation treatment in sea grape cultures to increase the quality and nutritional value of the product.