Judul: Kualitas mikrobiologis sosis daging sapi dengan penambahan bakteriosin sebagai bahan pengawet alami
Abstrak: One of the purposes of food preservation is to extend the self life of food. Nowadays, biological food preservation technology gets special attention from people. Beef sausage is one of meat product which is potential as medium for microbial growth. Many techniques have been applied to reduce microbial growth and to preserve the beef sausage. The most of preservation method use a chemical preservatives which can give healthy effect for human. Therefore, biopreservative is needed to replace chemical preservative. One of the biopreservative is bacteriocin produced by Lactobacillus plantarum 2C12. The aim of the research was to observe the microbiological characteristics of the sausage with the addition of preservatives (control, 0.3% nitrite, and 0.3% crude bacteriocin) at different storage time (0, 3, 6 and 9 day) in cold temperature (4-6 oC). The concentration of the protein produced from stages of cell free supernatan bacteriocin precipitates, and crude bacteriocin were 74 ± 18.38; 120.5 ± 7.78; 151 ± 2.83. This suggests that the protein concentration increased in each stage. Fresh meat purity test results showed that the total number of microbes is 2,19x104 cfu/g, Staphylococcus aureus 4.71x102 cfu/g, and 0.00 cfu/g for Escherichia coli and Salmonella spp. The quality of microbiologists sausage of beef show the total number of microbes that are contained in sausage of beef control, nitrite, and bakteriosin still in accordance with the safe limit consumption by SNI 01-3820-1995. Salmonella spp. and Eschirichia coli not found in beef sausage. Bacteriocin inhibits the growth of pathogenic bacteria especially Staphylococcus aureus in beef sausage. This shows that bacteriocin can replace the nitrite as a preservative with storage for six days at refrigerator temperature
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Judul: Aplikasi Bakteriosin sebagai Pengawet terhadap Kualitas Fisik dan Kimia serta Organoleptik Sosis Daging Sapi Selama Penyimpanan
Abstrak: Meat is a food material which contains high nutritions that needed by human. People often consume some foods which contain artificial preservative, characterized poison and carcinogenic. Bacteriocin was a natural preservative produced by Lactobacillus plantarum 2C12. The aim of this research was to study the physical, chemical and organoleptic quality of sausage during storage time. The treatments of preservative addition were sausage without preservative addition, sausage with nitrit addition 0,3 %, or sausage with bacteriocin addition 0,3 %. The treatments of long storage were 0 day, 3 days, 6 days, and 9 days. The treatments of preservative addition and storage time were influential to physical, chemical of the sausage. Sausage of bacteriocin addition was better than sausage of nitrit addition
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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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