Judul: Kompatibilitas Minyak Kayu Putih dari Daerah Papua, Mojokerto, Bupolo, Kuningan, dan Ponorogo sebagai Ingredien Flavor Cajuputs® candy
Abstrak: Cajuputs® candy adalah permen keras yang menggunakan minyak atsiri kayu putih sebagai flavor. Minyak atsiri kayu putih yang digunakan saat ini berasal dari Pulau Buru, Maluku, yang ketersediaannya mengalami keterbatasan. Minyak atsiri kayu putih (MKP) juga dihasilkan di beberapa daerah lain di Indonesia, namun tidak semua MKP kompatibel untuk digunakan sebagai flavor Cajuputs® candy. Penelitian ini bertujuan mempelajari kompatibilitas MKP dari daerah Papua, Mojokerto, Bupolo, Kuningan, dan Ponorogo sebagai ingredien flavor Cajuputs® candy secara sensori dan mikrobiologi. Uji sensori yang dilakukan meliputi uji beda dari kontrol, uji hedonik dan uji QDA, sedangkan uji mikrobiologi yang dilakukan adalah uji penghambatan aktivitas pembentukan biofilm S. mutans. Hasil uji sensori beda dari kontrol dan uji rating hedonik menunjukkan tidak ada perbedaan nyata antara Cajuputs® candy dengan MKP dari daerah Papua, Mojokerto, Bupolo, Kuningan, dan Ponorogo terhadap kontrol pada taraf signifikansi 5%, sehingga MKP kelima daerah tersebut secara penerimaan sensori kompatibel sebagai ingredien flavor Cajuputs® candy. Pada uji deskriptif QDA diperoleh 8 atribut sensori pada Cajuputs® candy. Atribut sensori tersebut adalah flavor minyak kayu putih, peppermint flavor, spicy flavor, green flavor, rasa manis, rasa pahit, bitter aftertaste, dan soothing effect. Hasil uji QDA menunjukkan bahwa MKP dengan karakter sensori yang lebih mirip dengan profil kontrol adalah dari daerah Bupolo, Mojokerto, dan Papua dengan karakterisitik sensori dominan rasa manis. MKP Ponorogo dikarakterisasi oleh atribut green flavor, spicy flavor, dan bitter aftertaste. MKP Kuningan dikarakterisasi oleh atribut rasa pahit, soothing effect, peppermint flavor, dan flavor minyak kayu putih. Hasil uji mikrobiologi menunjukkan bahwa semua sampel MKP yang diuji memiliki daya hambat terhadap pembentukan biofilm S. mutans. MKP daerah Mojokerto, Bupolo, dan Papua memiliki daya hambat lebih baik dibandingkan MKP daerah Ponorogo dan Kuningan. Hasil penelitian menunjukkan bahwa MKP paling kompatibel sebagai ingredien flavor Cajuputs® candy secara sensori dan kemampuan anti-mikrobanya adalah MKP Mojokerto, Bupolo, dan Papua.
Keyword: Cajuputs® candy, kompatibilitas, mikrobiologi, sensori

Judul: Profil Komponen Volatil Minyak Atsiri Kayu Putih dari Berbagai Daerah dan Pengaruhnya terhadap Profil Flavor Cajuputs Candy.
Abstrak: Essential oils of cajuput and peppermint have been utilized as bioactive components and flavor. Volatile components influence the flavor quality. The cultivation and production of cajuput essential oils are spread over Indonesia regions such as Java, East Nusa Tenggara, and Sulawesi. This study was conducted to determine the profile of cajuput essential oils from various regions in Indonesia related to their application compatibility into Cajuputs candy products. The quality of cajuput essential oils were analyzed for their physico-chemical properties including of color, density, refractive index, optical rotation, solubility in alcohol 70%, and cineol content. The composition of the volatile components were analyzed by using GC-MS. Sensory evaluation was done in terms of its acceptance by rating hedonic test and the similarity of its sensory character to commercial Cajuputs candy by different from control test. Physical and chemical properties measurement showed that the density, refractive index, and solubility in alcohol 70% of all samples had adjacent values, whereas in terms of color, optical rotation, and cineol content had diverse values. Cajuput essential oil that came closest to the target in term of physico-chemical characteristic was oil from Pulau Buru. The cajuput essential oil chromatogram pattern of Sukabumi, Indramayu, Gundih, Mojokerto, and Pulau Buru were similar while the chromatogram pattern of Atambua and Madura were somewhat different. No conclusion regarding the compatibility of evaluated essentials oils into the Cajuputs candy could be made yet due to the weakness of sensory evaluation method.
Keyword: Cajuputs candy, essential oils of cajuput, flavor, GC-MS, sensory

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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