Judul: Pengaruh Jenis Pelarut terhadap Total Terpenoid dan Kapasitas Antioksidan Ekstrak Rimpang Temulawak  (Curcuma zanthorrhiza)
Abstrak: Temulawak (Curcuma zanthorrhiza) merupakan tanaman asli Indonesia mengandung antioksidan dan terpenoid yang mampu menangkal radikal bebas. Sampel rimpang temulawak diekstraksi dengan berbagai jenis pelarut diperlukan untuk mendapatkan senyawa bioaktif temulawak terbaik secara kuantitatif. Penelitian ini bertujuan menentukan pengaruh berbagai jenis pelarut ekstraksi terhadap total terpenoid dan kapasitas antioksidan rimpang temulawak. Sampel diekstraksi dengan gabungan metode sonikasi dan maserasi. Tahapan penelitian meliputi pengujian kadar total terpenoid rimpang temulawak, kemudian dilanjutkan pengujian kapasitas antioksidan dengan metode DPPH, CUPRAC, FRAP, dan ABTS. Hasil penelitian menunjukkan kadar total terpenoid terbesar dihasilkan oleh pelarut H (heksan p.a) sebesar 243.74 ± 8.13a mg UA/g DW dan kapasitas antioksidan terbesar dihasilkan oleh metode FRAP dengan pelarut aseton sebesar 131.25 ± 4.33a. Berdasarkan data dapat disimpulkan terpenoid bukan merupakan komponen utama senyawa antioksidan pada rimpang temulawak karena perbedaan pelarut yang dihasilkan antara data kapasitas antioksidan dan kadar total terpenoid., Temulawak (Curcuma xanthorrhiza) is a plant native to Indonesia that contains antioxidants and terpenoids which are able to ward off free radicals. Temulawak rhizome samples were extracted with various types of solvents to obtain the best bioactive compounds in curcuma quantitatively. This research aimed to determine the effect of various types of extraction solvents on the total terpenoids and antioxidant capacity of curcuma rhizomes. Samples were extracted by a combination of sonication and maceration methods. The research stages included testing the total terpenoid content of curcuma rhizomes, then continued with testing the antioxidant capacity using the DPPH, CUPRAC, FRAP, and ABTS methods. The results showed that the highest total terpenoid content was produced by the H solvent (hexane p.a) of 243.74 ± 8.13a mg UA/g DW and the largest antioxidant capacity was produced by the FRAP method with acetone solvent of 131.25 ± 4.33a. Based on the data, it can be concluded that terpenoids are not the main component of antioxidant compounds in curcuma rhizomes due to differences in the solvent produced between antioxidant capacity data and total terpenoid levels.
Keyword: curcuma, types of solvent, antioxidant, terpenoids

Judul: Pengaruh Variasi Pelarut dan Waktu Ekstraksi Rimpang Temulawak terhadap Total Fenolik, Flavonoid, dan Aktivitas Antioksidan
Abstrak: Temulawak (Curcuma xanthorrhiza) mengandung senyawa metabolit sekunder seperti fenolik dan flavonoid yang berpotensi sebagai antioksidan. Senyawa metabolit sekunder yang banyak ditemukan dalam temulawak adalah kurkuminoid yang tergolong dalam senyawa polifenol. Maserasi merupakan metode sederhana untuk mengekstrak senyawa metabolit sekunder dari tumbuhan. Selama prosesnya, jenis pelarut dan waktu maserasi menjadi faktor penting yang dapat memengaruhi hasil ekstraksi. Penelitian ini bertujuan untuk menganalisis pengaruh pelarut (akuades, etanol 50%, metanol 50%, dan aseton 50%) dan waktu ekstraksi (12, 24, 36, dan 48 jam) terhadap kadar total fenolik, total flavonoid, dan aktivitas antioksidan. Hasil pengujian menunjukkan bahwa etanol 50% memberikan hasil terbaik dengan kadar fenolik 36,29 mg GAE/g, flavonoid 66,96 mg QE/g, dan aktivitas antioksidan (metode CUPRAC) 117,13, Temulawak (Curcuma xanthorrhiza) contained secondary metabolite compounds such as phenolics and flavonoids with potential antioxidant activity. The most abundant secondary metabolite compound found in temulawak was curcuminoid. Maceration was a simple method for extracting secondary metabolite compounds from plants. During maceration, the type of solvent and the maceration time were crucial factors that affected the test results. This study aimed to analyze the effect of solvent (aquadest, 50% ethanol, 50% methanol, and 50% acetone) and extraction time (12, 24, 36, and 48 hours) on total phenolics, total flavonoids, and antioxidant activity. The results showed that 50% ethanol yielded the highest phenolic content (36,29 mg GAE/g), flavonoid content (66,96 mg QE/g DW), and antioxidant activity (CUPRAC method) of 117.06
Keyword: antioxidant, phenolic, flavonoid, solvent, time

Judul: Model Input-output dalam Masalah Network Flow
Abstrak: Production process is a process, which is done by industry, to transform input into output. According to the type of output and its activity, industry can be classified into various sectors, which are connected to each other. Therefore, a model to analyze the connection among sections is needed. The model is known as input-output model (IO model). IO model presents an IO table, which shows informations about the transaction between goods and services in each economic sector. Furthermore, the IO model also shows that the amount of all input is the same as the amount of all output. In this paper, the transaction of each economic sector in IO table is analyzed using network flow theory. The formulated network flow problem implies that each sector represents partly as a producer and also as a consumer. This paper also solves a minimum cost circulation problem.
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