Judul: Physicochemical, Antioxidant, and Organoleptic Properties of Yogurt with the Addition of Moringa Leaf Powder (Moringa Olifera)
Abstrak: Yogurt susu sapi merupakan salah satu jenis minuman dari hasil proses fermentasi yang memiliki kandungan yang baik. Penambahan ini berguna untuk menambah kandungan gizi pada yogurt. Daun kelor mengandung banyak zat gizi yang dapat mengatasi masalah gizi buruk. Penelitian ini bertujuan menganalisis sifat fisikokimia, antioksidan dan organoleptik yogurt susu sapi dengan penambahan serbuk daun kelor. Taraf pemberian serbuk daun kelor tersebut adalah 0% (P1) sebagai kontrol, 5% (P2), 10% (P3), 15% (P4). Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan tiga kali pengulangan. Pengujian yogurt daun kelor terdiri dari analisis fisikokimia (nilai pH, viskositas, kadar abu, dan kandungan protein), sifat antioksidan (aktivitas dan kapasitas antioksidan) dan Uji organoleptik terhadap warna, aroma, dan rasa, tekstur dari produk yogurt daun kelor. Hasil penelitian ini menunjukkan bahwa penambahan serbuk daun kelor pada yogurt berpengaruh nyata (P<0,05) terhadap pH, viskositas, kadar abu, kadar protein, dan antioksidan. Selain itu hasil hedonik dan mutu hedonik menunjukan berpengaruh nyata (P<0,05) pada parameter warna, aroma, rasa, dan tekstur., Cow's milk yogurt is one type of beverage from the fermentation process that has good content. This addition is useful for increasing the nutritional content of yogurt. Moringa leaves contain many nutrients that can overcome the problem of malnutrition. The purpose of this research is to analyze the physicochemical, antioxidant and organoleptic properties of cow's milk yogurt with the addition of Moringa leaf powder. The level of administration of Moringa leaf powder was 0% (P1) as a kontrol, 5% (P2), 10% (P3), 15% (P4). This study used a completely randomized design (CRD) with three repetitions. Moringa leaf yogurt testing consisted of physicochemical analysis (pH value, viscosity, ash content, and protein content), antioxidant properties (antioxidant activity and capacity) and Organoleptic Test on color, aroma, taste, texture of Moringa leaf yogurt products. The results of this study showed that the addition of Moringa leaf powder to yogurt had a significant effect (P<0.05) on pH, viscosity, ash content, protein content, and antioxidants. In addition, the results of hedonic and hedonic quality showed a significant effect (P<0.05) on the parameters of color, aroma, taste, and texture.
Keyword: antioksidan, daun kelor, yogurt

Judul: Physicochemical and Organoleptic Properties of Yoghurt With the Addition of Min Leaf Powder (Mentha piperita)
Abstrak: Susu dapat diolah menjadi salah satu pangan fungsional yang populer di masyarakat dan salah satunya diolah menjadi yoghurt. Pengembangan pengolahan yoghurt diantaranya dengan penambahan daun min sebagai bahan alami yang mempunyai manfaat, tetapi tidak berpengaruh buruk dalam proses pengolahan dan produk akhir yang dihasilkan. Penelitian ini bertujuan untuk menganalisis sifat fisikokimia dan organoleptik yoghurt yang diberi penambahan serbuk daun min. Rancangan yang digunakan dalam penelitian ini adalah menggunakan Rancangan Acak Lengkap (RAL) dengan perlakuan penambahan serbuk daun min dengan konsentrasi yang berbeda yaitu 1) Tanpa penambahan serbuk daun min; 2) Penambahan daun min 4,54%; 3) Penambahan serbuk daun min 9,08%. Pengujian fisikokimia adalah pH, viskositas, TAT, dan antioksidan. Pengujian sifat organoleptik yang dianalisis adalah warna, aroma, kekentalan, dan rasa. Hasil penelitian menunjukkan bahwa penambahan daun min berpengaruh sangat nyata (p<0,01) terhadap kandungan antioksidan yoghurt, namun tidak berpengaruh nyata terhadap warna, aroma, rasa, dan kekentalan. Uji hedonik menunjukkan bahwa penambahan daun min berpengaruh nyata (p<0,05) terhadap warna, aroma, dan rasa. Hasil uji mutu hedonik menunjukkan bahwa penambahan daun min terhadap yoghurt memberikan pengaruh nyata (p<0,05) terhadap warna, aroma, rasa, dan kekentalan. Dengan demikian dapat disimpulkan bahwa penambahan daun min memberikan peningkatan nilai antioksidan dan peningkatan jumlah daun min yang ditambahkan berbanding terbalik dengan nilai uji hedonik dan uji mutu hedonik., Milk can be processed into one of the functional foods that are popular in the community and many are developed into yogurt. One of the developments is by adding mint leaves into yoghurt as a natural ingredient that has benefits, but does not adversely affect the processing process and the final product produced. This study was aimed to analyze the physicochemical and organoleptic properties of yogurt with the addition of min leaf powder. This study was used a completely randomized design with the addition of mint leaf powder at different concentrations, namely 1) Without the addition of mint leaf powder; 2) Addition of 4.54% mint leaf powder; 3) Addition of 9.08% mint leaf powder.. The organoleptic properties analyzed were color, aroma, viscosity, and taste. The results showed that the addition of mint leaves had a very significant effect (p<0.01) on antioxidant level of yoghurt, but had no significant effect on color, aroma, taste, and viscosity. The hedonic test showed that the addition of mint leaves had a significant effect (p<0.05) on the color, aroma, and taste. The results of the hedonic quality test showed that the addition of mint leaves to yogurt had a significant effect (p<0.05) on the color, aroma, taste, and viscosity. Thus, it can be concluded that the addition of mint leaves increased the antioxidant level, but the increase in the number of mint leaves added was also inversely proportional to the value of the hedonic test and the hedonic quality test.
Keyword: antioxidant, yogurt, mint leaves

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: