Judul: Ekstraksi dan identifikasi senyawa bioaktif lintah laut (Discodoris sp.) sebagai antioksidan
Abstrak: One of the commodities produced from the ocean that have a bioactive compounds is a sea slug (Discodoris sp.). That is very interesting to study mainly deals with the nature of both chemical and biochemical characteristics and their use for the field of food and health. The purpose of this study is to determine the nutrient content of sea slug, determine antioxidant activity, and determine the bioactive compounds of sea slug. The experiment was conducted with several stages: sample preparation, extraction bioactive compound, fractionation by TLC and identification of compounds by GC-MS. Sea slug from the island of Madura Pamekasan potential as a source of protein, fat, and minerals. Sea slug has esensial amino acids amount to 5,57% was dominated by leucin of 1,42%. Nonesensial amino acids amount to 6,54% wich was dominated by glutamic acid 2,19%. Saturated fatty acids amounted to 27.53% of sea slug was dominated by palmitic (C16:0) which was 13.36%. Unsaturated fatty acids amounted to 34.66%, which was dominated by the essential fatty acids linolenic (C18:3, n-3) 20.91%. The highest yield of the crude extract was ethanol of 6,97% and contained alkaloid, steroids, saponin, phenols, carbohydrates and reducing sugar compound. The bioactive compounds in the meat of sea slug with ethanol solvent was galoxolide, dibuthyl phthalate, di-n-octhyl phthalate, oleic acid amide, erucylamide, squalene and has an IC50 best antioxidant activity in fraction 5 at 150.92 ppm.
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Judul: Formulasi Minuman Fungsional Omega-3 dari Lintah Laut (Discodoris sp.)
Abstrak: Water resources such as Sea slug (Discodoris sp.) can be made as functional beverages. One of the important compound in Sea slug is omega-3 fatty acid. Omega-3 fatty acid is useful for our healthy. The study aimed to determine the best formulation based on the content of omega-3 in functional beverage of sea slug. The study was conducted in three phases: 1) the preparation of raw materials (Discodoris sp.), 2) the preparation of additional ingredients (ginger and soybean), 3) the stage of formulation of the functional beverage products. There were are three formulation, formulation A1 (Discodoris sp. 20%, ginger 35%, soybean 45%), A2 (Discodoris sp. 25%, ginger 35%, soybean 40%), and A3 (Discodoris sp. 30%, ginger 35%, soybean 35%). The best formulation with highest omega-3 and sensory was achieved in formulation A1. Sea slug functional beverage can be sources of omega-3 fatty acid. Testing the stability of the parameters chemical and microbiological shelf life by showing prediction of critical parameters is TPC, the formula A1 has a shelf life of 64 days at 30 oC, 70 days at 35 oC, and 84 days at 45 oC. The higher storage temperature the shelf life of the product will be longer.
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Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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