Judul: Pendugaan Umur Simpan dan Analisis Keamanan Cookies Berbasis Pati Garut (Maranta arundinaceae L) dengan Penambahan Torbangun (Coleus amboinicus Lour)
Abstrak: The purpose of this study was to determine the shelf life of arrowroot starch-based cookies with the addition of torbangun and to analyze the products’ safety during storage. Estimation cookies’s shelf life was calculated using the Accelerated Shelf Life Testing method with the approach of critical water. This method then followed by storage the cookies for 12 weeks with polypropylene and metalized plastic packaging. The cookies were analyzed every four weeks. The analysis consisted of organoleptic test, and product damage parameters such as pH, total acid titration, thiobarbituric acid, peroxide levels and total microbes. The results showed that cookies have a shelf life as long as 22 months with metalized plastic packaging and five months with polypropylene plastic packaging at 75% Relative Humadity (RH) storage. During the 12 weeks of storage, the organoleptic value was still acceptable. The storage duration and also the type of packaging used were not significant different (p> 0.05) against all damage parameters of the product.
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Judul: Prediction of Shelf Life and Analyses of the Safety of Arrowroot Starch (Maranta arundinaceae L)-Based Cookies with the Addition of Torbangun (Coleus amboinicus Lour).
Abstrak: The purpose of this study was to determine the shelf life of arrowroot starch-based cookies with the addition of torbangun and to analyze the products’ safety during storage. Estimation cookies’s shelf life was calculated using the Accelerated Shelf Life Testing method with the approach of critical water. This method then followed by storage the cookies for 12 weeks with polypropylene and metalized plastic packaging. The cookies were analyzed every four weeks. The analysis consisted of organoleptic test, and product damage parameters such as pH, total acid titration, thiobarbituric acid, peroxide levels and total microbes. The results showed that cookies have a shelf life as long as 22 months with metalized plastic packaging and five months with polypropylene plastic packaging at 75% Relative Humadity (RH) storage. During the 12 weeks of storage, the organoleptic value was still acceptable. The storage duration and also the type of packaging used were not significant different (p> 0.05) against all damage parameters of the product.
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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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