Judul: The Diversity of Fermented Foods in Indonesia and Comparison of The Nutrient Content of Milk-Based Fermented Foods
Abstrak: Indonesia mempunyai kelimpahan dan keragaman komoditas pangan, termasuk pangan fermentasi. Namun, analisis metadata tentang diversitas pangan fermentasi belum dilaporkan. Selain itu, perbandingan kandungan gizi pangan fermentasi berbasis susu juga belum tersedia. Oleh karena itu, penelitian ini bertujuan mengungkap status diversitas pangan fermentasi, mengetahui kandungan gizi terutama dari pangan fermentasi berbasis susu yakni dangke dan perbandingannya di antara produk fermentasi berbasis susu. Metode penelitian meliputi studi literatur, pembuatan dangke, analisis proksimat dangke, dan analisis data secara statistika. Studi literatur menunjukkan bahwa makanan dan minuman fermentasi di Indonesia paling banyak dilaporkan oleh artikel masing-masing pada tahun 2017, 2018, dan 2019. Walaupun sebagian besar pangan fermentasi tidak diketahui daerah asalnya, namun kelompok mikroba yang terlibat dalam pengolahannya diketahui paling banyak berasal dari kelompok bakteri dibandingkan fungi, terutama melalui mekanisme fermentasi asam laktat. Peranan mikroba dalam produk fermentasi beragam dan dapat dikelompokkan ke dalam lima kelompok. Peranan mikroba utamanya, yaitu mendukung bioproses. Di antara produk fermentasi berbasis susu, dangke merupakan produk tradisional dengan kandungan lemak yang berbeda signifikan dengan yoghurt, kefir, dan dadih serta proteinnya tidak berbeda signifikan dengan yoghurt, kefir, dadih, dan keju mozzarella. Analisis kandungan gizi ini mengindikasikan terdapat perbedaan kadar lemak dan protein di antara produk pangan fermentasi berbasis susu., Indonesia has high abundance and diversity of food commodities, including fermented food. However, metadata analysis about the diversity of fermented foods has not been reported. In addition, a comparison of the nutritional content of milk-based fermented foods is also not yet available. Therefore, this study aimeds to reveal the diversity status of fermented foods, to determine the nutritional content, especially of fermented milk-based foods, namely dangke and their comparisons between milk-based fermented products. The research method included literature study, making dangke, proximate analysis of dangke, and statistical data analysis. Literature studies show that fermented foods and beverages in Indonesia were most reported in 2017, 2018, and 2019 respectively. Although most fermented foods are not known for their area of origin, the microbial groups involved in their processing are known to come from the bacterial group rather than fungi, mainly through the lactic acid fermentation mechanism. The role of microbes in fermented products are diverse and can be grouped into five groups. The main role of microbes is to support bioprocesses. Among milk-based fermented products, dangke is one of the traditional products with a fat content that is significantly different fat content from yoghurt, kefir, and dadih and the protein is not significantly different from yoghurt, kefir, dadih, and mozzarella cheese. This analysis of nutritional content indicates that there are differences in fat and protein content among fermented milk-based food products.
Keyword: dangke, fat content, metadata, protein content, proximate analysis

Judul: Perbandingan Karakteristik Mikrobiologi dan Organoleptik Dali dan Dangke serta Keju Segar Asal Susu Kambing.
Abstrak: Masyarakat Indonesia memanfaatkan susu kambing untuk diolah menjadi produk pangan secara tradisional. Pengolahan susu kambing dalam produk olahan susu diharapkan dapat menjadi salah satu alternatif untuk meningkatkan nilai konsumsi susu kambing tanpa mengurangi manfaat yang dikandungnya. Produk pangan yang diolah dari susu tersebut diantaranya adalah keju segar, dali (Sumatera Utara), dan dangke (Sulawesi Selatan). Tujuan penelitian ini adalah untuk mengkaji perbandingan karakteristik mikrobiologi dan organoleptik dali, dangke, dan keju segar. Penelitian ini dilakukan menggunakan Rancangan Acak Kelompok dengan 3 taraf perlakuan koagulant yang berbeda yaitu rennet, getah pepaya, dan daun Agave angustifolia, kemudian dilakukan uji ragam dan data non parametrik menggunakan uji Kruskal Wallis, jika ada perbedaan nyata digunakan uji banding berganda Tukey. Hasil penelitian menunjukkan bahwa angka lempeng total (TPC) dan angka kapang khamir tidak berbeda nyata (P>0.05) antar perlakuan. Hasil uji hedonik berpengaruh nyata (P<0.05) terhadap produk keju segar. Keju segar memiliki nilai organoleptik yang lebih baik dibandingkan produk dangke dan dali.
Keyword: dali, dangke, keju segar, susu kambing

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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