Judul: Pengaruh Nisbah Bahan Baku – Pelarut dan Suhu Ekstraksi terhadap Kandungan Xanthorrhizol dalam Oleoresin Temulawak (Curcuma xanthorhiza roxb.).
Abstrak: Temulawak (Curcuma xanthorrhiza Roxb.) belongs to the plant family Zingiberaceae which have various benefits. Sidik et al (1995) described that temulawak can be used as anti-inflammatory, anti-cancer, medicine for many disease like hipokolesterolemia, disorders of liver function, improved gastrointestinal function, for anti-bacterial and anti-fungal, and as anti-acne. Those benefits are related to active components of temulawak rhizhome. Curcuminoids and xanthorrhizol are predicted as components that provides pharmacological effects of temulawak rhizomes. Curcuminoids is the pigment that gives yellow color to temulawak, while xanthorrhizol is one component of the essential oil of temulawak. Temulawak is usually prepared as rhizome slices, powder, oleoresin, and essential oil. Temulawak in form of rhizome slices or powder has some weaknesses, such as bulky, easily to have color and flavor defect caused by climate change, easily contaminated by foreign material and microorganism, slowly produce of active component in the stage application and not completely extracted, and the final product have spots or strain that caused by the rhizome particles (Ravindran et al, 2007). To avoid these weaknesses, temulawak can be processed into temulawak oleoresin. Oleoresin is defined as a mixture of resin and volatile oil extracted from various kinds of herbs, either from the fruit, seeds, leaves, bark, and rhizomes by using organic solvents (Glibertson, 1971). In the process of extraction using this solvent, there are several factors that can affect the extraction efficiency and effectiveness. These factors include the type and concentration of solvent, solvent volume, extraction temperature, and size of the extracted material In this research, extraction temperature and solvent volume were observed to determine their effect on xanthorrhizol content of temulawak oleoresin. The effects of these factors were measured on yield of oleoresin, curcumin content, volatile oil content, solvent residu and the refractive index of the oleoresin. Extraction temperature applied in the experiments were three levels, 30 oC, 40 oC and 50 oC. The solvent volume factor is indicated by the ratio of raw materials to solvent. This study observed three levels of ratio, 1:4, 1:6, and 1:8 using 100 grams of temulawak powder as the ratio basis. Preparation prior to extraction process includes rhizome slicing, drying, and grinding to the size of 60 mesh. Temulawak powder was extracted by stirred maceration using ethanol 96% for four hours, followed by conditioning in room temperature for 24 hours. Temulawak extract was then separated from the solid waste by filtration. The evaporation to remove the solvent from the oleoresin finally conducted using a rotary vacuum evaporator at temperature of 50oC. The yields of temulawak oleoresin are in the range of 9.40% - 17.77% (w / w). The curcumin content is 1.11 to 3.88%, the essential oil content is 3,64 - 11.43%, the xanthorrhizol content equal to peak percentage area of 1.26 - 42.82%, the solvent residu in the oleoresin is 40.950 – 63.750 ppm, and the refractive index value (20/20oC) is ranged from 1.4817 to 1.5198. Statistical analysis of variance at 95% confidence level was used to determine the influence of extraction temperature and raw material-solvent ratio on yield and other experiments parameters. The result showed that
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Judul: Pengaruh jumlah pelarut, lama ekstraksi dan ukuran bahan terhadap rendemen dan mutu oleoresin temulawak (Curcuma xanthorrhiza Roxb.)
Abstrak: Penelitian ini bertujuan untuk mempelajari pengaruh jumlah pelarut, lama ekstraksi dan ukuran bahan terhadap rendemen dan mutu oleoresin temulawak. Analisis mutu yang dilakukan adalah kadar minyak atsiri, sisa pelarut, kadar kurku- min, kadar pati, bobot jenis, kadar abu dan indeks bias minyak. Proses ekstraksi oleoresin dilakukan melalui tahapan proses, yaitu pengirisan, pengeringan, penggilingan, ekstrak- si dengan pelarut, penyaringan dan penguapan pelarut. Penelitian ini dilakukan melalui dua tahap yaitu penelitian pendahuluan dan penelitian lanjutan. Pada penelitian lanjutan digunakan rancangan percobaan Split-Plot dengan dua kali ulangan. Perlakuan yang dikenakan adalah jumlah pelarut (etanol), dengan taraf 400 ml, 600 ml dan 800 ml ; lama ekstraksi dengan taraf 1 jam, 3 jam dan 5 jam serta ukuran bahan (bubuk temulawak kering) dengan taraf 40 mesh dan 60 mesh. Hasil penelitian menunjukkan bahwa perlakuan jumlah pelarut dan interaksi antara lama ekstraksi dan ukuran bahan berpengaruh sangat nyata terhadap rendemen oleoresin, jumlah pelarut dan lama ekstraksi berpengaruh sangat nyata terhadap kadar minyak atsiri, sedangkan ukuran bahan berpengaruh nyata terhadap kadar minyak atsiri. Perlakuan jumlah pelarut berpengaruh nyata terhadap kadar abu dalam oleoresin. Perlakuan interaksi antara jumlah pelarut dan ukuran bahan berpengaruh nyata terhadap indeks bias minyak. Perlakuan jumlah pelarut, lama ekstraksi dan ukuran bahan serta interaksi diantaranya tidak memberikan pengaruh nyata dan sangat nyata terhadap kadar pati, kadar kurkumin, sisa pelarut dan bobot jenis oleoresin. ..
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.