Judul: Pemanfaatan Rumput Laut Gracilaria verrucosa Sebagai Produk Bakto Agar dan Aplikasinya Dalam Media Pertumbuhan Mikroorganisme
Abstrak: Gracilaria verrucosa is a kind of seaweed cultivated in brackish water with water salinity of 6-14 ppt. Gracilaria produces a primary compound hydrocoloid metabolite called agarophyt. The aim of this study was to utilize Gracilaria as a bacto agar product with three methods of drying and also to apply bacto agar as a gelling agent in the microbial growth media. The source of Gracilaria sp used in this study was a seaweed that is cultivated by farmers in the village of Langen Sari, Subang. Characterization of raw materials included analysis of moisture content, ash content, protein content, fat content, and carbohydrate content. Acid treatment was carried out before the extraction processing which the acid treatment used of 1% CH3COOH. Temperature and extraction time constant were used at a temperature of 90oC for 45 minutes. Drying methods were done with three, oven dryer, spray dryer, and drum drier. The application of bacto agar as microbial growth media was applying the product by growing yeast and bacteria. Nutrient Agar has been used as a media for the growth of bacteria and Potato Dextrose Agar has been used as a media for the growth of yeast. The inoculation of microbial cultures performed in the plate agar media. In the plate agar media, syneresis occurred when the incubation was accomplished for 48 hours. Therefore additional tests were performed to determine the concentration of the bacto agar to reduce syneresis by testing the addition of gel strength with bacto concentration to 1.5%, 2%, and 2.5%.
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Judul: Nutrient enrichment and postharvest culture technology to enhance the quality of Gracilaria verrucosa
Abstrak: Gracilaria verrucosa merupakan rumput laut penghasil agar yang penting di Indonesia. Budidaya salah satu jenis Rhodophyta ini umumnya hanya mengandalkan air yang tersedia yang berada disekitar tambak, sehingga produksi yang tinggi berasal dari perluasan areal budidaya, bukan akibat peningkatan produktivitas rumput laut tersebut. Studi tentang rumput laut menunjukkan bahwa salah satu faktor pendukung meningkatnya produktivitas adalah ketersediaan nutrien yang memadai. Selain peningkatan produktivitas, hal yang harus dipertimbangkan dalam budidaya rumput laut, G. verrucosa adalah kualitas agar yang merupakan hasil ekstraksi dari rumput laut ini. Oleh sebab itu, penelitian ini mencoba untuk mengkaji peningkatan produktivitas melalui pengkayaan nutrien, dan memperbaiki kualitas agar rumput laut, G. verrucosa sejak masa budidaya. Penelitian ini bertujuan untuk mengetahui respon pertumbuhan G. verrucosa yang diberi pengkayaan berbagai nutrien, serta mengkaji efektivitas perlakuan gelap, juga kombinasi perlakuan gelap dan salinitas yang ditingkatkan pada budidaya pascapanen dalam meningkatkan kualitas G. verrucosa., The economic important of Gracilaria verrucosa is undoubted as its being the raw material world-wide in agar production. In Indonesia, cultivation of this species has been employed broadly, however this magnitude growth merely due to expansion of farm area. In general, farmers only rely on available water surround the pond for their culture condition, while previous studies mentioned that one factor to be considered to enhance productivity is the availability of nutrients properly. Besides quantities production of raw materials, it must be consistent with the quality of agar that extracted from Gracilaria verrucosa. This study was aimed to determine the growth response of G. verrucosa following a variety of nutrients enrichment, as well as to assess the quality of G. verrucosa upon he postharvest culture of dark or dark and increased salinity treatments.
Keyword: productivity, postharvest culture, agar content, agar production, gel strength, Gracilaria verrucosa, Postharvest cultivation technology, Food additive

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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