Antioxidant and antibacterial activities in 21 species of Indonesian sea cucumbers.

Sea cucumbers are marine organisms with uses in food, cosmetics, and medicine. This study aimed to identify Indonesian sea cucumbers with high antioxidant and antibacterial activities. Twenty-one sea cucumber species were used for this study. Antioxidant capacity was evaluated using the 2,2-diphenyl-ß-picrylhydrazine assay. Antibacterial activity was assessed using the disk diffusion assay, whereas the resazurin-based assay was employed to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Volatile compounds possibly related to the biological activity of sea cucumbers were analyzed via gas chromatography-mass spectrometry (GC-MS). Holothuria atra had the strongest antioxidant capacity (IC50 = 14.22 ± 0.87 µg µL-1). Stichopus vastus displayed the best antibacterial activity against Staphylococcus aureus, whereas Stichopus ocellatus extract was most potent against Vibrio cholerae. Holothuria albiventer, which controlled Bacillus subtilis most effectively while also being active against S. aureus and V. cholerae, was the optimal antimicrobial species. H. albiventer and Actinopyga echinites inhibited B. subtilis growth at 12.5 µg µL-1. The MBC tests indicated that the antibacterial activities of sea cucumbers at the MIC were bacteriostatic, rather than bactericidal, in nature. GC-MS analysis uncovered long-chain fatty acids that might be associated with the antibacterial activities of sea cucumbers.

Evaluation of Nutritional Composition of The Dried Seaweed Ulva lactuca from Pameungpeuk Waters, Indonesia.

The nutritional composition of the dried seaweed Ulva lactuca from Pameungpeuk waters, including proximate, vitamins, minerals, dietary fibre and heavy metal has been carried out. The objective of this present study is to know the nutritional composition of the dried seaweed U. lactuca for utilisation in human nutrition in the future. Results show that carbohydrate was the major component in the proximate analysis of U. lactuca in the present study. The carbohydrate content was 58.1%. Moisture, ash, protein and fat content were 16.9%, 11.2%, 13.6% and 0.19% respectively, while dietary fibre was 28.4%. The vitamin A content was examined in this study less than 0.5 IU/100 mg while vitamin B1 (thiamine) and vitamin B2 (riboflavin) were 4.87 mg/kg and 0.86 mg/kg respectively. The calcium content was 1828 mg/100 g higher than other minerals. The heavy metal content examined in this study were lower than the limit of the quality criteria applied to edible seaweeds sold in Indonesia. Based on the results of this study show that U. lactuca has potential to be developed as an alternative source of a healthy food for human in the future.