Improving coastal livelihoods through sustainable aquaculture practices - a report to the collaborative APEC Grouper Research and Development Network

Wild-harvest fisheries for live reef fish are largely over-exploited or unsustainable because of over-fishing and the widespread use of destructive fishing practices such as blast and cyanide fishing. Sustainable aquaculture – such as that of groupers – is one option for meeting the strong demand for reef fish, as well as potentially maintaining or improving the livelihoods of coastal communities. This report from a short study by the STREAM Initiative draws on secondary literature, media sources and four diverse case studies from at-risk reef fisheries, to frame a strategy for encouraging sustainable aquaculture as an alternative to destructive fishing practices. It was undertaken as a component of the APEC-funded project Collaborative Grouper Research and Development Network (FWG/01/2001) to better understand how recent technical advances in grouper culture and other complementary work – including that of the Asia-Pacific Marine Finfish Aquaculture Network (APMFAN) hosted by NACA – could better support the livelihoods of poor coastal communities. (PDF contains 49 pages

Chemical composition of dried Stevia rebaudiana Bertoni leaves and effect of ultrasound-assisted extraction on total steviosides content in extract

Introduction: Steviol stevioside, which has been used in the production of food products as a low-calorie sweeten, is one of the main glycoside groups in the leaves of the Stevia plants. It is useful for human health. Objective: The main objection of the present study was to find out some major chemical compositions of the dried Stevia rebaudiana Bertoni leaves and an effective, affordable, and environmentally friendly method to reach the high extraction yield of total steviosides from them. Therefore, a novel extraction, ultrasound-assisted extraction (UAE), was carried out to extract total steviosides from dried leaves of S. rebaudiana plant with ethanol of 70% (v/v) as a solvent. Methods: Some major chemical compositions of the dried S. rebaudiana leaves were analyzed according to the AOAC (Association of Official Analytical Chemists) and total steviosides content (TSC) was measured by anthrone-sulphuric acid colorimetric assay with main influencing factors including material/solvent ratio, extraction temperature, and extraction time. Results: The results referred that some chemical compounds such as protein, lipid, fibre, sugar, etc. existed in this material. The best extraction conditions were the sample/solvent ratio of 1:100 (g/ml), extraction temperature of 75oC, and extraction time of 30 min. Conclusion: The highest amount of total steviosides content of 8.894 % was obtained at the optimal extraction condition. Consequently, these results demonstrated that the parameters of UAE were applied successfully for producing total glycosides

Chemical composition and cellulase-assisted extraction of total saponins from Gomphrena celosioides Mart.

The major purpose of the present study was to determine the chemical composition of dried Gomphrena celosioides Mart., including crude protein, lipid, total sugar, reducing sugar, ash, crude fiber, moisture, crude pectin, and total saponins in particular. This plant contains a large percentage of total saponins, which are widely used in food technology and pharmaceutical industries. In our study, the conditions for the extraction of total saponins from the plant were optimized, with special focus on cellulase concentration, pH, hydrolyzation time, and temperature. The highest amount of total saponins content (TSC) was 1.550±0.016% under optimal extraction conditions (cellulase concentration: 0.7% (v/w), hydrolyzation time: 4 h, hydrolyzation temperature: 60EC, and pH value: 5). Accordingly, the total saponins from G. celosioides Mart. were easily extracted