Judul: Karakteristik Keju Lunak Probiotik dari Susu Kambing dengan Penambahan Ekstrak Herbal dan Pengaruhnya dalam Penghambatan Aktivitas Enzim α-amilase
Abstrak: Herbs are widely used in culinary and as traditional medicine. Previous study investigated mint, dill and basil extract inhibition on enzim correlated with type 2 diabetes, was α-amylase. The objective of this research is to identify the physical, chemical, microbiological and sensory quality of mint, dill and basil cheeses. The result of this study showed that herb extract reduced pH of cheese during fermentation faster than plain cheese. The yield of mint and basil cheese were not very significantly different with plain cheese, but lower in dill cheese (P<0.01). The highest total phenolic content (TPC) was found in basil cheese (316.14 ± 12.72 μg GAE/g cheese DW). Herbs cheeses very significantly (P<0.01) inhibited DPPH (1,1-diphenyl-2-picrylhydrazyl) and α-amylase activity, with the highest activity for each assay respectively were dill and mint cheese, 0.23 ± 0.02 % and 2.89 ± 0.17 % per mg cheese DW respectively. DPPH inhibition of plain and mint cheese was dose-independent, but otherwise in dill cheese. Herbs extract increased total LABs of cheese. Regression equations of DPPH inhibition (Y), TPC (X) and total LABs (Z) were Y = 5.467 + 0.1555X; (R2 = 35%; P <0.05), Y= 1.931Z – 8.209 (R2 = 44.8%; P<0.05) and X = 7.186 + 0.06965Z (R2 = 58.4%; P <0.01) respectively. The best formula of herbs cheese based on sensory quality is dill cheese. This study indicated the therapeutic potentiality of mint, dill or basil extract included-probiotic soft cheese produced from goat milk as functional food for people with type 2 diabetes.
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Judul: Karakteristik Keju Lunak Probiotik dengan Bahan Koagulan Kalsium Klorida pada Konsentrasi yang Berbeda
Abstrak: Cheese is one of dairy products produce by using rennet as coagulant enzym. The use of rennet as coagulant has some problems such as limited availability and unguaranted halalness. Calcium chloride can be used as a substitution of milk coagulation process by rennet. The experiment was aimed to test the ability of calcium chloride salts as coagulant in the cheese-making process and to study the characteristics of the produced cheese by the addition of the probiotic bacteria. Concentration of calcium chloride used were 5%, 7.5% and 10% with the addition of probiotic bacteria Lactobacillus acidophilus IIA-2B4 and Bifidobacterium longum RRM-01. Statistical design used in this experiment were Randomized Block Design. The data obtained were analyzed with ANOVA and Tukey test was performed if significant defference among variables data was detected. Based on the MFFB and population of lactic acid bacteria, the produced cheese can be categorized as a soft cheese and also categorized as a probiotic food. The addition of calcium cloride at different consentrations did not effect significantly on the tested variables (viscosity, yield, nutrient composition, pH and total titrable acid, population of lactic acid bacteria, S, aureus, coliform and hedonic test) when compared with cheese coagulated by rennet as positive control, whereas calcium salt coagulation time showed highly significant difference (P<0.1) when compared with rennet, but did not differ significantly between the calcium salts. Thus the suggested level of addition of calcium chloride for cheese making is 5%.
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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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