Edible sea grapes (Caulerpa lentillifera) are produced in shaded ponds (~ 50 μmol photons m−2 s−1) and are of increasing demand for direct human consumption. The controlled exposure to light-stress after harvest could increase algae's content of nutritionally valuable antioxidants, including phenols. In order to define a light-stress tool for farmers to use, we investigated the effect of five irradiances (50–600 μmol photons m−2 s−1) for an exposure time of up to 14 days. Antioxidant activity (AOA, initial of 150.93 ± 25.50 mmol Trolox equivalents 100 g−1 DW) and total phenolic content (TPC, initial of 124.45 ± 10.07 mg Gallic acid equivalents 100 g−1 DW) significantly increased to values of up to 228.8 ± 12.4 and 222.2 ± 22.7 % of initial, respectively. However, targeted increases in antioxidant parameters correlated with decreased values of Fv/Fm (p < 0.001) and the chlorophyll (Chl) a content in the edible frond was significantly lower at irradiances ≥400 μmol photons m−2 s−1 compared to the control (50 μmol photons m−2 s−1), causing bleaching. As the physiological response of the alga (Fv/Fm, AOA, TPC, Chl a) depended on exposure time and irradiance treatment, both parameters could be adjusted to define treatments according to the consumer's needs. Light irradiances measured at a sea grape farm revealed that farmers could integrate such treatments labour- and cost-effectively by removing layers of plastic-meshes off their culture or post-harvest units. The pattern of Chl a loss and red (R) colour channel values in sea grapes thallus parts implied, that a combination of degradation and chloroplast migration was responsible for bleaching at light-stress. Additionally, R channel values extracted from pictures could be used for Chl a estimation, due to strong correlation (rS = −0.786, p < 0.001). In conclusion farmers can use high light as post-harvest treatment in order to increase valuable antioxidants.
Stuthmann L., Achuthan R., Pribbernow M., Du H.T., Springer K. and Kunzmann A. (2022) Improving the nutritional value of edible Caulerpa lentillifera (Chlorophyta) using high light intensities. A realistic tool for sea grape farmers. Algal Research 66: 102785. 10.1016/j.algal.2022.102785
@article{Stuthmann2022,
Title = {Improving the nutritional value of edible Caulerpa lentillifera (Chlorophyta) using high light intensities. A realistic tool for sea grape farmers},
Author = {Stuthmann, Lara and Achuthan, Revathi and Pribbernow, Mia and Du, Hoang Trung and Springer, Karin and Kunzmann, Andreas},
Editor = {},
Journal = {Algal Research},
Year = {2022},
Pages = {102785},
Volume = {66},
Doi = {10.1016/j.algal.2022.102785},
Abstract = {Edible sea grapes (Caulerpa lentillifera) are produced in shaded ponds (~ 50 μmol photons m−2 s−1) and are of increasing demand for direct human consumption. The controlled exposure to light-stress after harvest could increase algae's content of nutritionally valuable antioxidants, including phenols. In order to define a light-stress tool for farmers to use, we investigated the effect of five irradiances (50–600 μmol photons m−2 s−1) for an exposure time of up to 14 days. Antioxidant activity (AOA, initial of 150.93 ± 25.50 mmol Trolox equivalents 100 g−1 DW) and total phenolic content (TPC, initial of 124.45 ± 10.07 mg Gallic acid equivalents 100 g−1 DW) significantly increased to values of up to 228.8 ± 12.4 and 222.2 ± 22.7 % of initial, respectively. However, targeted increases in antioxidant parameters correlated with decreased values of Fv/Fm (p < 0.001) and the chlorophyll (Chl) a content in the edible frond was significantly lower at irradiances ≥400 μmol photons m−2 s−1 compared to the control (50 μmol photons m−2 s−1), causing bleaching. As the physiological response of the alga (Fv/Fm, AOA, TPC, Chl a) depended on exposure time and irradiance treatment, both parameters could be adjusted to define treatments according to the consumer's needs. Light irradiances measured at a sea grape farm revealed that farmers could integrate such treatments labour- and cost-effectively by removing layers of plastic-meshes off their culture or post-harvest units. The pattern of Chl a loss and red (R) colour channel values in sea grapes thallus parts implied, that a combination of degradation and chloroplast migration was responsible for bleaching at light-stress. Additionally, R channel values extracted from pictures could be used for Chl a estimation, due to strong correlation (rS = −0.786, p < 0.001). In conclusion farmers can use high light as post-harvest treatment in order to increase valuable antioxidants.},
}
TY - JOUR
AU - Stuthmann, Lara
AU - Achuthan, Revathi
AU - Pribbernow, Mia
AU - Du, Hoang Trung
AU - Springer, Karin
AU - Kunzmann, Andreas
TI - Improving the nutritional value of edible Caulerpa lentillifera (Chlorophyta) using high light intensities. A realistic tool for sea grape farmers
T2 - Algal Research
PY - 2022
SP - 102785
VL - 66
DO - 10.1016/j.algal.2022.102785
AB - Edible sea grapes (Caulerpa lentillifera) are produced in shaded ponds (~ 50 μmol photons m−2 s−1) and are of increasing demand for direct human consumption. The controlled exposure to light-stress after harvest could increase algae's content of nutritionally valuable antioxidants, including phenols. In order to define a light-stress tool for farmers to use, we investigated the effect of five irradiances (50–600 μmol photons m−2 s−1) for an exposure time of up to 14 days. Antioxidant activity (AOA, initial of 150.93 ± 25.50 mmol Trolox equivalents 100 g−1 DW) and total phenolic content (TPC, initial of 124.45 ± 10.07 mg Gallic acid equivalents 100 g−1 DW) significantly increased to values of up to 228.8 ± 12.4 and 222.2 ± 22.7 % of initial, respectively. However, targeted increases in antioxidant parameters correlated with decreased values of Fv/Fm (p < 0.001) and the chlorophyll (Chl) a content in the edible frond was significantly lower at irradiances ≥400 μmol photons m−2 s−1 compared to the control (50 μmol photons m−2 s−1), causing bleaching. As the physiological response of the alga (Fv/Fm, AOA, TPC, Chl a) depended on exposure time and irradiance treatment, both parameters could be adjusted to define treatments according to the consumer's needs. Light irradiances measured at a sea grape farm revealed that farmers could integrate such treatments labour- and cost-effectively by removing layers of plastic-meshes off their culture or post-harvest units. The pattern of Chl a loss and red (R) colour channel values in sea grapes thallus parts implied, that a combination of degradation and chloroplast migration was responsible for bleaching at light-stress. Additionally, R channel values extracted from pictures could be used for Chl a estimation, due to strong correlation (rS = −0.786, p < 0.001). In conclusion farmers can use high light as post-harvest treatment in order to increase valuable antioxidants.
ER -
