Judul: Kajian Penggunaan Ekstrak Angkak dalam Pembuatan Low Fat Fruity Yogurt Sebagai Pangan Fungsional.
Abstrak: Angkak or red fermented rice is a product produced from the fermentation of rice substrates by Monascus sp. For centuries, angkak has been consumed extensively in Asia as a natural food coloring of fish, Chinese cheese, red wine and sausages. Angkak has been used as dietary supplement because of its chemical compound that give advantages to human’s health. Therefore, angkak can be developed as functional food. Utilization of angkak extract is implemented to make low fat fruity yoghurt. The purpose of this study is to produce low fat fruity yoghurt with angkak extract that consumers like. This study also determines the effect of angkak extract to lactic acid bacteria, nutrition facts and antioxidant capacity of low fat fruity yoghurt. The result show that until 30% concentration of angkak exctract, there is no effect to the growth of lactic acid bacteria. The most favourite of low fat fruity yoghurt is yoghurt with 2.5% concentration of angkak extract and 20% of added fresh fruit. The chemical analysis results show that low fat fruity yoghurt contains 4.07 pH, 14.9 oBrix total soluble solid content and 1.26% titratable acid. The physical analysis result show that low fat fruity yogurt has 2500 mPas viscosity. The proximate analysis results show that low fat fruity yoghurt contains 85.59% water, 0.73% ash, 3.12% protein, 0.11% fat, and 10.45% carbohydrates. The microbial analysis results show that low fat fruity yoghurt contains 8.93 log CFU/ml total microbe, < 0.48 log CFU/ml total coliform, 9.65 log CFU/ml total lactic acid bacteria,and < 2 log CFU/ml total mold and yeast. The low fat fruity yoghurt has antioxidant capacity of 23.02 mgAEq/100ml, which means 100 ml low fat fruity yoghurt has equivalent antioxidant activity to 23.02 mg ascorbic acid.
Keyword: 

Judul: Chemical Properties and Total Lactic Acid Bacteria of Probiotik Yogurt with Addition of Red Fruit (Pandanus conoideus L.)
Abstrak: Produk susu fermentasi yang menggunakan bakteri Lactobacillus bulgaricus and Streptococcus thermophilus dan atau bakteri asam laktat lain disebut yogurt. Penambahan probiotik pada yogurt dapat membantu memperbaiki proses pencernaan. Buah merah memiliki kandungan senyawa antioksidan dan karotenoid. Penelitian ini bertujuan menganalisis sifat kimia dan total bakteri asam laktat yogurt probiotik dengan penambahan buah merah. Persentase buah merah yang ditambahkan ke dalam yogurt yaitu 0%, 2,5%, dan 5%. Pengujian yang dilakukan pada penelitian ini, yaitu uji sifat kimia meliputi kadar lemak, protein, air, abu, nilai pH, keasaman tertitrasi, serta uji total bakteri asam laktat. Analisis data yang digunakan adalah Rancangan Acak lengkap, dengan tiga kali ulangan. Hasil dari penelitian ini menunjukkan bahwa penambahan ekstrak buah merah ke dalam yogurt probiotik dengan persentase yang berbeda berpengaruh nyata (P<0,05) pada pH dan keasaman tertitrasi. Seluruh yogurt P0, P1, P2 menunjukkan nilai mikrobiologi yang sesuai sebagai minuman probiotik. Yogurt P1 dengan penambahan 2,5% ekstrak buah merah menjadi produk terbaik yang sesuai dengan mutu SNI., Fermented milk products that use Lactobacillus bulgaricus and Streptococcus thermophilus bacteria and or other lactic acid bacteria called yoghurt. The addition of probiotic to yoghurt can improve the digestive process. Red fruit contains antioxidants and carotenoids. This study aims to analyze the chemical properties and total lactic acid bacteria of probiotic yoghurt with addition of red fruit extract. The percentages of red fruit added to yoghurt is 0%, 2,5%, and 5%. The analysis carried out in this study was chemical analysis including the content of fat, protein, water, ash, pH value, titrated acidity, and total lactic acid bacteria. Data analysis used was Completely Randomized Design with three repetitions. The result of this research indicated that the addition of red fruit extract into probiotic yoghurt with different percentages had a significant effect (P<0,05) on pH and titrated acidity. All yoghurts P0, P1, P2 showed appropriate microbiological value as probiotic drinks. Yoghurt P1 with the addition of 2,5% red fruit extract is the best product according to the Indonesian National Standard.
Keyword: hemical properties, lactic acid bacteria, probiotic, red fruit, yoghurt

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.
Keyword: