Judul: The utilization of green tea (Camellia sinensis O. Kuntze) extract in the development of functional rice for Diabetes Mellitus patients
Abstrak: Tujuan penelitian ini adalah untuk mendapatkan beras dengan daya cerna pati in vitro rendah sebagai pangan fungsional untuk penderita diabetes melitus. Penurunan daya cerna pati dilakukan dengan perlakuan ekstrak teh hijau. Bahan penelitian adalah sepuluh varietas beras Indonesia, yaitu Pandan Wangi, Rojolele, Bengawan Solo, Cenana-Bali (beras merah), Memberamo, Celebes, Ciherang, Batang Piaman, Cisokan, dan Lusi (ketan). Beras diperoleh dari Balai Penelitian Tanaman Padi, Sukamandi. Sebagai pembanding digunakan beras Taj Mahal, yang di pasaran dikenal sebagai beras untuk penderita diabetes. Teh hijau (Camellia sinensis O. Kuntze) diperoleh dari Kebun Percobaan Pasir Sarongge, Cianjur. Penelitian dibagi menjadi empat tahap, yaitu: 1) Penapisan aktivitas hipoglikemik dan analisis komposisi kimia beras, 2) Proses pembuatan beras pratanak dan beras instan fungsional, 3) Evaluasi daya hipoglikemik beras fungsional dan analisis histologi jaringan pankreas, serta 4) Penentuan indeks glikemik (IG) beras. Pada penapisan aktivitas hipoglikemik diperoleh lima kategori varietas beras berturut-turut dari aktivitas hipoglikemik tertinggi sampai terendah, yaitu: 1) Cisokan, 2) Batang Piaman, 3) Memberamo, Cenana-Bali, Lusi, Bengawan Solo, 4) Pandan wangi, Taj Mahal, Celebes, Rojolele, dan 5) Ciherang. Varietas Memberamo terpilih untuk diproses menjadi beras fungsional, karena aktivitas hipoglikemiknya relatif tinggi, mengandung serat pangan larut (3.95%) dan pati resisten (2.68%) tertinggi di antara varietas yang diuji, serta memiliki kadar amilosa rendah (19.30%) sehingga tekstur nasi pulen dan rasa enak.
Keyword: Padi dan beras, Diabetes melitus, Pankreas, Indeks Glikemik pangan, Tanaman teh, Pangan fungsional, Analisis komposisi kimia beras, Penapisan aktivitas hipoglikemik, Beras pratanak fungsional, Beras instan fungsional, Pati in vitro, Uji organoleptik

Judul: Pengaruh Penambahan Ekstrak Teh Hijau pada Pengolahan Beras Ekstrusi Terhadap Penurunan Indeks Glikemik
Abstrak: Rice is a staple food for most people of Indonesia, which still not be replaced by another source of carbohydrate. This phenomenon is risky for people who have Type 2 Diabetes Mellitus (T2DM), because they not eat rice as normal people. This research was conducted to make food which can be eaten safely by people who has T2DM. There are 5% broken rice produced from rice milling process. The utilization of broken rice still limited in Indonesia. The main objective of this research was to develop extruded rice based on broken rice and the additional of polyphenolic substances from green tea extract by using extrusion technology. The additional of 4 % green tea extract on broken rice was conducted with 4 treatments: 1) without the additional of green tea extract, as control (K), 2) during rice soaking before milling (P1), 3) before the extrusion process (P2), and 4) combination of treatment 2 and 3 (P3). Starch digestibility (SD) analyzed by using in vitro method to determine the best treatment of green tea extract addition in lowering the digestibility of starch. The result showed that the fourth addition treatment of green tea extract had the lowest SD value as 47.31%. These data correlated to GI conducted with in vivo analysis. Glycemic Index (GI) of extruded rice result was 48.15 (low GI), whereas the GI of broken rice was 77.40 (high GI). The addition of green tea extract significantly reduced the GI value of extruded rice from broken rice.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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