Judul: The Effect of Methyl Jasmonate on the Quality of Papaya Fruit (Carica papaya L)
Abstrak: Pepaya adalah buah klimakterik yang mengalami puncak respirasi dan produksi etilen pada fase pematangan setelah panen. Umumnya, pepaya menghadapi kendala pascapanen seperti masa simpan yang singkat, kemudahan mengalami luka mekanis, tingkat respirasi yang tinggi, kehilangan kandungan air, serangan penyakit serta hama, dan chilling injury. Aplikasi metil jasmonat (MeJA) pada pascapanen telah umum dipraktikkan untuk meningkatkan masa simpan buah, meningkatkan kualitas buah, mengurangi chilling injury, dan meningkatkan resistensi buah terhadap penyakit yang disebabkan oleh fungi. Penelitian ini bertujuan mempelajari pengaruh aplikasi metil jasmonat pascapanen terhadap kualitas buah pepaya. Penelitian dilaksanakan di Laboratorium Pascapanen Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor yang berlangsung di bulan Juni 2023. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) satu faktor. Faktor tersebut adalah konsentrasi metil jasmonat yang terdiri atas empat taraf konsentrasi yaitu 0 mM (kontrol, penyimpanan suhu ruang), 0 mM (kontrol, penyimpanan suhu dingin), 0,1 mM (penyimpanan suhu dingin) dan 1 mM (penyimpanan suhu dingin). Hasil dari penelitian ini menunjukkan bahwa perlakuan metil jasmonat berpengaruh nyata terhadap pengurangan susut bobot buah pada 8 HSP, pengurangan pelunakan kulit buah pada 5 dan 8 HSP, pengurangan ATT, dan peningkatan rasio ATT/PTT jika dibandingkan dengan kontrol suhu ruang, tetapi tidak berbeda nyata jika dibandingkan dengan kontrol suhu dingin. Aplikasi metil jasmonat 1 mM memiliki persentase kulit buah berwarna hijau paling tinggi dan tingkat kematangan daging buah paling rendah berdasarkan warna daging buah pada 17 hari setelah panen., Papaya is a cilmacteric fruit which undergoes peak respiration and ethylen produuction during postharvest ripening and commonly face postharvest obstacles such as short shelf life, ease of mechanical injury, high respiration rate, loss of water content, disease & pest attack, and chilling injury. Application of methyl jasmonate (MeJA) in postharvest handling is commonly used to raise shelf life, increase fruit quality, reduce chilling injury, and boost fruit resistence against fungal attack. The objective of this study is to understand the effect of methyl jasmonate postharvest application on papaya fruit quality. This study was conducted at Postharvest Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University in June 2023. Completely Randomized Design (CRD) with one factor was applied. The factor was methyl jasmonate concentration ranging from 0 mM (control, room temperature), 0 mM (control, cold storage), 0,1 mM (cold storage), and 1 mM (cold storage). The result showed that application of methyl jasmonate significantly reduce fruit weight loss on 8 days after harvest, reduce peel softening on 5 and 8 days after harvest, reduce total titratable acid, and increase total soluble solid/total titratable acid ratio if compared to room temperature control treatment, but showed no significant effect if compared to cold temperature control treatment. Fruits with methyl jasmonate 1 mM treatment showed highest percentage of green peel color and lowest maturity level based on fruit flesh color on 17 days after harvest.
Keyword: chilling injury, chemical content, color scale, physical quality, postharvest

Judul: Study of waxing on quality and storability of Callina papaya fruit
Abstrak: Pepaya (Carica papaya L.) merupakan salah satu buah-buahan tropika yang menjanjikan di pasar baik dalam maupun luar negeri, dan mempunyai nilai ekonomi yang cukup tinggi. Buah pepaya termasuk dalam jenis buah klimakterik.. Salah satu cara untuk menahan laju penurunan mutu dalam penanganan pascapanen buah-buahan adalah dengan pelilinan dan penyimpanan dingin.penelitian ini bertujuan untuk mempelajari pengaruh pelilinan terhadap kualitas dan daya simpan buah pepaya Callina pada suhu ruang dan suhu dingin (130C). Konsentrasi lilin yang digunakan adalah 0% (kontrol), 6%, dan 10% dengan metode pencelupan. Hasil penelitian menunjukkan bahwa buah pepaya dengan konsentrasi 10% pada suhu 130C mampu menekan laju respirasi, susut bobot, kekerasan, dan warna kulit buah pepaya. Namun, pelilinan tidak terlalu berpengaruh pada perubahan nilai TPT. Hasil uji organoleptik menunjukkan bahwa buah pepaya yang diberi lapisan lilin dengan konsentrasi 10% mampu mempertahankan tingkat kesukaan panelis. Begitu pula dengan uji pembobtan, kombinasi konsentrasi dan suhu terbaik yaitu pada buah pepaya dengan konsentrasi pelilinan 10% pada suhu 13 °C. Kekerasan buah termasuk parameter mutu kritis buah pepaya., Papaya (Carica papayaL.) is one of tropical fruits which economically good both in domestic and overseas. Papaya fruit is kind of climacteric fruit. One way to hold the rate of quality degradation in post-harvest handling is by waxing and cold storing. This research aim to learn the effect of waxing about quality and storability of Calina papaya at room temperature and cold temperature (13°C). Wax concentrations which was used were 0% (control), 6%, and 10% by dyeing method. The result showed that papaya with wax concentration 10% at 13°C could hold the rate of respiration, weight loss, hardness, and colour of fruit. However, waxing did not affect greatly on the changes of Total Dissolved Solid (TDS). Organoleptic result showed that waxed papaya in 10% of concentration was good according to the panelists. It also showed good result for weighting, good combination can be reached at 10% of wax concentration and 13°C of temperature. Hardness fruit including critical parameter of papaya.
Keyword: pepaya, pelilinan, suhu

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: