Nutritional Value and Biofunctionalities of Two Edible Green Seaweeds (Ulva lactuca and Caulerpa racemosa) from Indonesia by Subcritical Water Hydrolysis.

Caulerpa racemosa (sea grapes) and Ulva lactuca (sea lettuces) are edible green seaweeds and good sources of bioactive compounds for future foods, nutraceuticals and cosmeceutical industries. In the present study, we determined nutritional values and investigated the recovery of bioactive compounds from C. racemosa and U. lactuca using hot water extraction (HWE) and subcritical water extraction (SWE) at different extraction temperatures (110 to 230 °C). Besides significantly higher extraction yield, SWE processes also give higher protein, sugar, total phenolic (TPC), saponin (TSC), flavonoid contents (TFC) and antioxidant activities as compared to the conventional HWE process. When SWE process was applied, the highest TPC, TSC and TFC values were obtained from U. lactuca hydrolyzed at reaction temperature 230 °C with the value of 39.82 ± 0.32 GAE mg/g, 13.22 ± 0.33 DE mg/g and 6.5 ± 0.47 QE mg/g, respectively. In addition, it also showed the highest antioxidant activity with values of 5.45 ± 0.11 ascorbic acid equivalents (AAE) mg/g and 8.03 ± 0.06 trolox equivalents (TE) mg/g for ABTS and total antioxidant, respectively. The highest phenolic acids in U. lactuca were gallic acid and vanillic acid. Cytotoxic assays demonstrated that C. racemosa and U. lactuca hydrolysates obtained by HWE and SWE did not show any toxic effect on RAW 264.7 cells at tested concentrations after 24 h and 48 h of treatment (p < 0.05), suggesting that both hydrolysates were safe and non-toxic for application in foods, cosmeceuticals and nutraceuticals products. In addition, the results of this study demonstrated the potential of SWE for the production of high-quality seaweed hydrolysates. Collectively, this study shows the potential of under-exploited tropical green seaweed resources as potential antioxidants in nutraceutical and cosmeceutical products.

Sea lettuces: culinary uses and nutritional value.

In many countries, sea lettuces are commonly consumed as food by human since the beginning of times. Sea lettuces contain significant amount of nutrients which are essential for human body. Moreover, several studies have provided insight into biological activities and health promoting effects of sea lettuces. Despite having so much health beneficial effects, sea lettuces are still identified as an underexploited plant resources for food purposes. Hence, sea lettuces have a great potential for further development as products in foods and pharmaceutical areas. Further, potential applications of polysaccharides, protein and amino acid, lipid and fatty acid, mineral and vitamin contents may increase the sea lettuces value. This contributions presents information on the currently culinary use of sea lettuces worldwide and nutritional aspects of sea lettuces.