Judul: Aktivitas Antioksidan dan Karakteristik Kimia Susu Pasteuriasi dengan Penambahan Bubuk Kapulaga Jawa (Amomum compactum)
Abstrak: Kecenderungan gaya hidup sehat telah memotivasi masyarakat untuk mengonsumsi produk pangan yang memiliki dampak positif bagi kesehatan. Penambahan kapulaga jawa pada susu pasteurisasi diharapkan akan meningkatkan nilai fungsional susu yang bermanfaat bagi kesehatan. Penelitian ini bertujuan menganalisis karakteristik kimia dan aktivitas antioksidan susu pasteurisasi dengan penambahan bubuk kapulaga jawa sebesar 0,5%, 1%, dan 1,5%. Penelitian dilakukan menggunakan Rancangan Acak Lengkap (RAL) dengan satu faktor. Data yang diperoleh dianalisis menggunakan ANOVA. Hasil penelitian dengan penambahan bubuk kapulaga jawa 1,5% menunjukkan perbedaan nyata (P<0,05) pada aktivitas antioksidan, kapasitas antioksidan serta kadar protein. Susu pasteurisasi dengan penambahan bubuk kapulaga jawa sebesar 1,5% memperoleh hasil terbaik untuk analisis karakteristik kimia dan aktivitas antioksidan dikarenakan memiliki kadar protein dan aktivitas antioksidan yang tinggi dibandingkan dengan perlakuan lain, yaitu protein (4,98%), aktivitas antioksidan (24,27%) dan kapasitas antioksidan (125,90 mg EVC 100 g-1).
Keyword: Antioxidant, Javanese cardamom, Pasteurized milk

Judul: Antioxidant Activity dan Chemical Properties of Pasteurized Milk with the Addition of Lemongrass Powder (Cymbopogon citratus)
Abstrak: Public awareness about the safety of food additives has led to an increase in demand for safer sources of natural antioxidants. This study aimed to analyze the chemical properties and antioxidant activity of pasteurized milk with the addition of lemongrass powder. Lemongrass powder was added to the milk pasteurization process at levels of 0%, 1.5%, 2.0% and 2.5%. This study used a complete randomized design and the data were analyzed by variety analysis. The results showed that the addition of lemongrass powder increased inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl, antioxidant capacity, protein content, and lactose of pasteurized milk. Pasteurized milk plus 2.5% lemongrass powder shows the best formula based on increased antioxidant activity, antioxidant capacity, protein content, and lactose., Kesadaran masyarakat tentang keamanan bahan tambahan pangan menyebabkan permintaan sumber antioksidan alami yang lebih aman meningkat. Penelitian ini bertujuan untuk menganalisis sifat kimia dan aktivitas antioksidan susu pasteurisasi dengan penambahan bubuk serai. Bubuk serai ditambahkan pada proses pasteurisasi susu dengan taraf 0%, 1,5%, 2,0% dan 2,5%. Penelitian ini menggunakan rancangan acak lengkap dan data dianalisis dengan analisis ragam. Hasil penelitian menunjukkan bahwa penambahan bubuk serai meningkatkan aktivitas penghambatan terhadap 2,2-diphenyl-1-picrylhydrazyl, kapasitas antioksidan, kadar protein, dan laktosa susu pasteurisasi. Susu pasteurisasi yang ditambah 2,5% bubuk serai menunjukkan formula terbaik berdasarkan peningkatan aktivitas antioksidan, kapasitas antioksidan, kadar protein, dan laktosa.
Keyword: antioxidant, lemongrass, pasteurized milk

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.
Keyword: