Judul: Identifikasi Character Impact Compounds Flavor Beras Aromatik (Oryza myristica L.) Asli Indonesia
Abstrak: Consumers prefer aromatic rice because of its pleasant aroma when it is eaten. Study on the aroma components of Indonesian aromatic rice is still limited. The objective of this study was to evaluate the composition of aroma components in aromatic rice (varieties of Pandan Wangi Garut, Pandan Wangi Cianjur, and Rojolele) and non-aromatic rice (IR-64) and to identify the character impact compounds of aromatic rice in the variety Pandan Wangi Garut by Aroma Extract Dilution Analysis (AEDA) method. The aroma components of non aromatic rice (IR-64) were also analyzed to compare the composition results. The aroma component of aromatic and non aromatic rice were extracted using Simultaneously Distillation Extraction (SDE) Likens Nickerson method and were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O). The number of aroma components identified in aromatic rice was vary between 17 to 48 compounds, whereas non aromatic rices had 17 compounds. Their chemical classes are aldehides, alcohols, heterocyclic compounds, esters, hydrocarbons, ketones and carboxylic acids. The difference between aromatic and non aromatic rice was the occurence of 2-acetyl-1-pyrroline and the concentration of hexanal, 1-pentanol, acetophenone, 1-octen-3-ol, (E,E)-2,4-decadienal and 2-penthylfuran. Their similarity was the concentration of ethyl acetate. The character impact compounds of aromatic rice Pandan Wangi Garut were 2-acetyl-1-pyrroline, which has sweet, pleasant, pandan aroma, and ethyl acetate which has a caramel and fruity aroma.
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Judul: Kandungan 2-Asetil-1-Pirolina dan Heksanal pada Beberapa Varietas Beras (Oryza Sativa L.) Aromatik Selama Penyimpanan dengan Beragam Derajat Sosoh dan Jenis Pengemas
Abstrak: Scented rice or aromatic rice varieties is popular because of their flavor and texture. 2-Acetyl-1-pyrroline (2AP) contribute to pandan-leaves-like aroma, and hexanal is used as indicator of rancidity. Three aromatic cultivars (Mentik Wangi, Pandan Wangi, and Sintanur) with 100, 90, and 0% (brown rice) milling degree were stored in two types of packaging, i.e., plastic bag and hermetic bag for 4 months in room temperature. 2-Acetyl- 1-pyrroline and hexanal were determinded every 2 month during storage using gas chromatography mass spectrophotometer. Prescribed nutrient content with proximate analysis including moisture, ash, fat, protein, and amylose content, were done at the begining and at the end of storage time. Preference of rices was done by hedonic test. 2- Acetyl-1-pyrroline concentration decreasing during storage and as increasing with the milling degree. Brown rice have a highest hexanal than 90% and 100% of milling degree. Hexanal increased during 2 month storage, and decreased in 4 month storage. During storage, moisture, ash content, protein, and fat were still in standard range according to several references. Based on the amylose content, the texture all of rice before storage was sticky category and after four months of storage fell into smooth until hard texture. however ash and fat content were increasing. From preference test, Mentik Wangi 100% milling degree before storage is the most prefered rice than others. Both of hermetic bag and plastic bag gives no different influence in this case.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf