Judul: Karakter Kulit Manggis, Kadar Polifenol Dan Potensi Antioksidan Kulit Manggis (Garcinia mangostana L.) Pada Berbagai Umur Buah Dan Setelah Buah Dipanen
Abstrak: The objective of this study were to know the character of mangosteen rind during development of the mangosteen fruit, studying the total phenol content and antioxidant potential of mangosteen rind. Research was done at Plant Analysis and Chromatoghrapy Laboratory, Deparment of Agronomy and Horticulture, Bogor Agricultural University. This research used Completely Randomized Desain Group (RKLT) single factor wich is harvesting, with continue test Duncan Multiple Range Test (DMRT) at level 5%. Harvesting one month after anthesis (BSA), 2 BSA, 3 BSA, 4 BSA and the rind storage two and four weeks after harvesting were done separately. Mangosteen fruit was harvested from Leuwiliang, Bogor. The result showed that total phenolic at crude extract mangosteen and antioxidant capacity to reach IC50 of harvesting and storage have negative correlation. Harvesting handling have effect to fruit weight, aril weight, wet weight rind and vitamin C content. Total phenolic of Harvesting and storage handling have a negative correlation with antioxidant capacity to reach IC50 which are value about -0.53 and -0.91. Assumed that total phenolic content will increase antioxidant capacity in mangosteen rind. Antioxidants capacity on harvesting and sorage handling of mangosteen have IC50<50 (capability of antioxidant are very strong).
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Judul: Pelapisan Manggis Segar (Garcinia mangostana L.) dengan Lilin Lebah, Hormon Giberelin, dan Benomil
Abstrak: Mangosteen (Garcinia Mangostana L) is one of fruit which has high economic value. The constraint of Mangosteen selling is wilt speed of fruit calyx, that could be assumed as decrease of quality by consumer thinking. Because of that condition, selling activity also decreased. One of way of to lengthen the fruit shelf-life is coating. Coating has known as a protecting substance of food, reduce the transpiration of product, and protect products from microbial contamination. So, the constrain which faced aspecially for seller and exporter for maintain mangosteen quality and freshness can be solved. The purpose of this research are knowing maturity degree of mangosteene which use as a raw material for next research that is knowing organoleptyc and physical effects of coating consentrations during storage. This research consists of two phases. Phase I decide of maturitie’s degree (2 , 3, and 4) and temperature’s storage (room and cool). Phase II decide consentration of coating agent. Types of concentration agent are consisted two levels of beeswax (4 and 6%), three levels of giberelic acid (5, 10, and 15 ppm), and two levels of benomyl (500 and 1000 ppm). The parameters were observed during storage involve physical parameter (visual sheath, weight reduce, husk hardness, and husk colour) and organoleptyc test (kernel and fruit husk colour, ratch vision, taste, and flavour). Based on regretion analysis result visual sheath and weight reduce, the third maturity degree has slope value (2,443 and 0,008). that result have smaller vvalue than others. Result of that maturitie’s organoleptyc test was accepted by consumer in cool storage temperature until 12 days. While room storage until 9 days. The 6% concentration of beeswax coating has smaller slope value at parameters sheath, reduce weight, and hardness husk than others (2,109; 0,007; 0,017). Not only that parameters but also organoleptyc test knowed that consentration had higher accepted consumer than others. The 10 ppm concentration of giberelic acid coating has smaller slope value at parameters sheath, reduce weight, and hardness husk than others (2,453; 0,001; 1,579). According organoleptyc test knowed that consentration had higher accepted consumer than others. The 1000 ppm concentration of benomyl coating has smaller slope value at parameters sheath, reduce weight, and hardness husk than others (2,237; 0,009; 0,179). Not only that parameters but also organoleptyc test knowed that consentration had higher accepted consumer than others.
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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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