Judul: Analisis Mutu dan Umur Simpan Es Yogurt Sinbiotik dengan Parameter Obyektif dan Subyektif
Abstrak: Lactobacillus acidophilus 2B4, salah satu probiotik indigenus, diaplikasikan dalam pembuatan es yogurt sinbiotik di Usaha Kecil Menengah (UKM) dengan FOS 5% sebagai sumber prebiotik. Tujuan dari penelitian ini adalah menganalisis kualitas es yogurt yang diproduksi dan menentukan umur simpan produk tersebut. Berdasarkan penelitian ini, es yogurt yang diproduksi belum memenuhi standar SNI 2981:2009. Kadar protein pada produk akhir adalah 1.3%, sedangkan syarat kadar protein pada SNI 2981:2009 adalah minimal 2.7%. Umur simpan ditentukan berdasarkan viabilitas bakteri asam laktat. Produk memiliki umur simpan 57.5 hari. Selama masa simpan tersebut, pH dan TAT (Total Asam Tertitrasi) produk tetap sesuai dengan SNI 2981:2009 dan penerimaan konsumen terhadap produk tergolong tinggi.
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Frukto-oligosaccharide, L acidophilus 2B4, Shelf life, Synbiotic ice yogurt

Judul: Analisis Mutu dan Umur Simpan Es Yogurt Sinbiotik dengan Parameter Obyektif dan Subyektif
Abstrak: An indigenous probiotic, Lactobacillus acidophilus 2B4, was applied in the making of functional synbiotic ice yogurt with fructo-oligosaccharide 5% as a prebiotic source. The objective of this research was to analyze the product quality and to determine the shelf life of the product. The product quality was analyzed based on SNI 2981:2009. The requirement sited in SNI 2981:2009 was not completely fullfilled by the product because the protein content in final product was only 1.3% while the requirement is minimal 2.7%. The shelf life was determined based on the viability of lactic acid bacteria. The product had shelf life 57.5 days. During the shelf life, the pH and titratable acidity conformed the requirement in SNI 2981:2009 and the sensory quality of the product was accepted by the consumer
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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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