Judul: Pengaruh Tingkat Sterilitas pada Proses Pengalengan Terhadap Sifat Fisik Gudeg yang Dihasilkan
Abstrak: Gudeg is a traditional food of Yogyakarta and Central Java, Indonesia, made from boiled young jack fruit with spices, palm sugar, and coconut milk. Canning process at high temperature (above 1000C) can extend shelf life gudeg and shorten cooking process which takes a long time (up to 12 hours). Appropriate design of a thermal process is required to provide the required preservation, with the least amount of damage to the organoleptic and nutritional quality of the product. The aim of this research is to obtain the effect of F0 values (4, 12, 20, and 28 min) in sterilization of gudeg to its physical properties. The result shows that treatment of temperature 111, 116, and 1210C at same F0 value has no significant difference in color and texture changing. Based on hedonic test, the most favorite sample is gudeg which is processed at 1210C for 57.1 min (F0=20 min). This product has nutritious content: 75.40% water, 1.55% ash, 5.68% fat, 0.83% protein, 16.54% carbohydrate, 1.97% fiber, and 120.60 Kcal energy. Product has pH 5.68 and aw 0.934 (included potentially hazardous food), then commercial sterility in canning process is appropriate heat treatment.
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Judul: Pengaruh Tingkat Sterilitas, Medium Dan Ketebalan Tempe Terhadap Sifat Fisik Dan Nilai Gizi Tempe Kaleng
Abstrak: Tempeh is a traditional Indonesian food product derived from fermented soybeans using Rhizopus oligosporus. Tempeh has many advantages, such as nutrients and organic compounds in which a fairly complete as well as health benefits and can be obtained with relatively lower prices than other soy products are known to the world community. Tempeh also contains isoflavones as antioxidants. Unfortunately, tempeh has a limiting factor of the quality and short shelf life. Damage that occurs in tempeh mainly is caused by continuous fermentation. Therefore, in this study, thermal process was conducted so that tempeh has longer shelf life. The aim of this research is to obtain the effect of Fo values (4, 8, and 12 minutes), mediums (water, 2% brine, and oil), and tempeh thicknesses (1, 3, and 5 cm) in sterilization of tempeh to its physical properties and nutritional values. The results show that canned tempeh has softer texture, no significant difference in slicing quality and colour, and lower pH value than raw tempeh. However, all variables had no significant effect to physical properties changing. Based on hedonic test, the most favourite sample is tempeh in oil with 3 cm thickness which canned at T=127oC and Fo=4 minutes. This product has 51.98% water content, 1.04% ash content, 34.97% protein, 60.55% fat, and 2.32% of carbohydrate. The total daidzein and total genistein in 100 g product are 2.40 mg and 2.95 mg.
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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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