Judul: Filtration and Antioxidant Activity of Commercial Fermented and Non-Fermented Sausage
Abstrak: Antioksidan merupakan senyawa yang dapat menghambat dan mencegah terjadinya proses oksidasi. Penelitian ini bertujuan menyaring peptida dari sosis fermentasi dan non fermentasi yang tersedia komersial di pasar lokal, melihat kandungan kimia produknya, dan menentukan aktivitas antioksidannya. Kandungan kimia sosis diuji dengan uji proksimat dan uji Lowry, sementara aktivitas antioksidan dengan metode DPPH. Data dianalisis dengan uji ANOVA. Hasil menunjukkan pada analisis proksimat hanya kadar air dan kadar lemak ketiga sosis yang berbeda (P<0,05). Konsentrasi protein sosis fermentasi nyata lebih tinggi dibandingkan sosis non fermentasi (P<0,05), dengan protein tertinggi pada sosis fermentasi Pepperoni. Ekstrak sosis sapi non fermentasi memiliki nilai IC50 lebih besar (log 2,07 ppm atau 117 ppm) dari sosis pepperoni dan salami (P<0,05). Nilai IC50 terbaik dalam menghambat reaktivitas DPPH adalah pada sosis fermentasi pepperoni, diikuti oleh salami dan sosis non fermentasi. Ini menunjukkan fermentasi mampu meningkatkan kandungan kimia dan kemampuan antioksidan sosis fermentasi produk tersebut., Antioxidants are compounds that can inhibit and prevent the process of oxidation. This study aims to screen peptides from commercially available fermented and non-fermented sausages in the local market, examine the chemical content of the products, and determine their antioxidant activities. The chemical content of the sausages was tested using proximate analysis and the Lowry assay, while the antioxidant activity was assessed using the DPPH method. The data were analyzed using ANOVA.The results showed that in the proximate analysis, only the water and fat content of the three sausages differed significantly (P<0.05). The concentration of protein in the fermented sausages was significantly higher than in the non-fermented sausages (P<0,05), with the highest protein content found in the fermented Pepperoni sausage. The non-fermented beef sausage extract had a higher IC50 value (log 2.07 ppm or 117 ppm) compared to Pepperoni and Salami sausages (P<0,05). The best IC50 value in inhibiting DPPH reactivity was found in the fermented Pepperoni sausage, followed by Salami and non-fermented sausages. This indicates that fermentation can increase the chemical content and antioxidant capabilities of the fermented sausage products.
Keyword: antioxidant, bioactive peptides, fermented sausage, filtration, IC50

Judul: Karakteristik Sifat Fisik, Kimia, Dan  Organoleptik Sosis  Sapi Dengan Pe rendaman Dalam Substrat  Antimikroba  Lactobacillus sp.  (1A5) Pada Penyimpanan  Suhu Dingin
Abstrak: Sausages are a food product that has been consumed by many people in the world. Sausages are normally processed with nitrite in order to keep them endure longer before they are consumed. After further study has been conducted, it is now known that nitrite contains elements that are carcinogenic, therefore further researches has been conducted to find an alternative for nitrite as a food preservative. Antimicrobial Subtract from Lactic Acid Bacteria Lactobacillus sp. (1A5) are suspected to be a natural form of alternative preservatives. Those conducted research are designed to study and explore the sausages physical, chemical, and sensory characteristics of the product, with submersion the sausages in antimicrobial subtract, then storing them at different period of time in refrigerated storage. This research gave a variety of result. The pH and peroxide level were very influenced by those two methods, while the water absorption was influenced by the different period of time method, only. Those two methods were not significantly affected to physical and chemical component. The sensory test has a different result in every criteria of quality, except the ooze level and firmness that are not significantly different.
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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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