Judul: Peningkatan Nilai Gizi Mi Basah dengan Fortifikasi Sawi Hijau dan Umbi Bit
Abstrak: Noodles is a flour-based food which is the second most consumed in the world after bread. Various modifications are needed in order to produce nutritious noodles, one of them is fortification with vegetables. This study aimed to increase the nutritional content of noodles through the fortification with green mustard and beet. Parameters analyzed including proximate, vitamin C content, iron and calcium contents, and antioxidant activity. The results were compared with control noodles (without fortification). Carbohydrate content increased 1.4 and 0.2%, and crude fiber content increased to 0.24 and 0.17% for mustard green and beet noodles, respectively. The vitamin C content in green mustard noodles increased 10 times and beet noodles increased twice compared with the control noodles. Fortification with green mustard increased the iron and calcium contents 40 and 21%, respectively. The best antioxidant activity was showed by beet noodles with % inhibition at 20 ppm of 2.97% against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Based on these results, it can be concluded that fortification with green mustard increased the crude fiber, vitamin C, iron, and calcium contents, while the beet fortification increased the crude fiber and vitamin C contents as well as the antioxidant activity.
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Judul: Characteristics of Sweet Potato Noodles Substitution by Sago Starch or Banggai Starch and Calcium Fortification
Abstrak: Ubi jalar adalah pangan lokal yang mendukung program diversifikasi pangan melalui pengaplikasian sebagai bahan baku pembuatan produk yang banyak disukai oleh masyarakat, salah satunya adalah mi. Penambahan pati sagu dan pati ubi banggai pada adonan mi ubi jalar diharapkan dapat meningkatkan kualitas mi yang dihasilkan, karena kedua pati ini memiliki karakteristik lebih mudah mengalami retrogradasi. Pengolahan menggunakan ekstruder dapat meningkatkan kualitas mi yang dihasilkan melalui pemberian panas dan shear stress. Peningkatan kualitas mi ubi jalar dari segi kandungan nutrisi dapat dilakukan dengan fortififikasi kalsium agar produk mi ubi jalar menjadi pangan sumber kalsium yang dapat mencegah terjadinya osteoporosis. Untuk memperoleh cara pengolahan mi terbaik, pada penelitian ini dilakukan tiga perlakuan, yaitu perbedaan jenis pati (pati sagu dan pati ubi banggai), suhu ekstrusi (90 dan 95ºC), dan penambahan air (35 dan 40%). Cara pengolahan terbaik dipilih berdasarkan hasil pengukuran warna, tekstur (kekerasan, kekenyalan, kelengketan, elongasi), dan cooking loss. Pada formula mi ubi jalar terpilih, dilakukan fortifikasi kalsium dengan dua garam kalsium yang berbeda, yaitu kalsium karbonat dan kalsium sitrat, masing-masing pada konsentrasi 20 dan 30% AKG dan dilanjutkan dengan pengukuran warna, tekstur, cooking loss, dan uji hedonik. Hasil pengujian pada mi ubi jalar menunjukkan bahwa perlakuan perbedaan jenis pati, penambahan air, dan suhu ekstrusi memengaruhi karakteristik fisik mi. Penambahan pati sagu 15%, air 40%, dan pengaturan suhu 95°C dapat menghasilkan mi ubi jalar dengan karakteristik warna agak gelap serta terdapat unsur warna merah dan kuning, memiliki nilai kekerasan diatas 3000 gf, dengan kekenyalan dan elongasi lebih tinggi dibandingkan formula yang lain, serta nilai kelengketan dan cooking loss yang lebih rendah. Fortifikasi kalsium karbonat ataupun kalsium sitrat, konsentrasi 20 dan 30 % AKG pada formula ini menunjukkan adanya perbedaan secara signifikan, yaitu dapat meningkatkan intensitas kecerahan, warna merah, dan kuning pada mi. Fortifikasi kalsium pada mi ubi jalar tidak mempengaruhi tingkat kekerasan, kekenyalan, kelengketan, elongasi, dan cooking loss. Penilaian panelis terhadap tingkat kesukaan menunjukkan bahwa secara keseluruhan mi ubi jalar fortifikasi kalsium dapat diterima oleh panelis., Sweet potato is a local food that supports food diversification programs through its application as a raw material for making products that are liked by common people, one of which is noodles. The addition of sago starch and banggai starch to the sweet potato noodle dough is used to improve the quality of noodles, because these two starches are more prone to retrograde. Processing using an extruder by applying heat and shear stress can improve the quality of the noodles produced. Improving the quality of sweet potato noodles in terms of the components contained can be done by calcium fortification so that sweet potato noodle products become food sources of calcium that can prevent osteoporosis. In order to obtained the best noodle processing method, three treatments were carried out in this study, there were different types of starch (sago starch and banggai starch), extrusion temperature (90 and 95ºC), and the addition of water (35 and 40%). The best processing method was selected based on the measurement of color, texture (hardness, elasticity, stickiness, and elongation), and cooking loss. In the selected sweet potato noodle formula, calcium fortification was carried
Keyword: calcium, fortification, noodles, starch, sweet potato

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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