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: Effect of Storage Temperature and Soaking in Methyl Jasmonate on Fruit Quality of Kecapi Fruit (Sandoricum koetjape (Burm. f.) Merr.)
Abstrak: Buah kecapi (Sandoricum koetjape (Burm. f.) Merr.) masih melakukan aktivitas metabolisme setelah dipanen karena termasuk buah klimaterik. Penyimpanan suhu dingin dapat mengurangi aktivitas metabolisme, namun kecapi termasuk salah satu buah yang sensitif terhadap suhu dan akan mengalami gejala chilling injury saat disimpan di suhu rendah yang tidak tepat. Penelitian ini bertujuan mengetahui suhu simpan dan lama perendaman methyl jasmonate yang sesuai untuk menjaga kualitas buah kecapi selama masa penyimpanan. Penelitian ini menggunakan rancangan acak lengkap dua faktor yaitu suhu simpan (27,94 °C dan 3,03 °C) dan lama perendaman dalam 0,1 mM methyl jasmonate (10 menit dan 30 menit). Hasil penelitian menunjukkan gejala chilling injury sudah terlihat di minggu pertama penyimpanan baik di perlakuan kontrol maupun di buah yang sudah diberi perlakuan methyl jasmonate. Buah yang disimpan di suhu dingin dan diberi perlakuan perendaman methyl jasmonate memiliki kualitas fisik buah lebih baik dibanding perlakuan lainnya. Nilai rata-rata peningkatan susut bobot pada perlakuan tersebut sebesar 11,48% dan 11,80% selama masa penyimpanan., Kecapi fruit (Sandoricum koetjape (Burm. f.) Merr.) still carries out metabolic activity after being harvested because it is a climacteric fruit. Cold storage can reduce metabolic activity, but kecapi is one of the fruits that is sensitive to temperature and will experience chilling injury symptoms when stored at inappropriately low temperatures. This study aims to determine the appropriate storage temperature and soaking time for methyl jasmonate to maintain the quality of kecapi fruit during the storage period. This study used a completely randomized design with two factors, storage temperature (27,94 °C and 3,03 °C) and soaking duration in 0,1 mM methyl jasmonate (10 minutes and 30 minutes). The results showed that chilling injury symptoms were visible in the first week of storage, both in the control treatment and fruit that had been treated with methyl jasmonate. Fruit stored at cold temperatures and soaked in methyl jasmonate had better physical fruit qualities than other treatments. The average value of the increase in weight loss in these treatments was 11,48% and 11,80% during the storage period.
Keyword: chilling injury, climacteric fruit, quality, soaking duration, weight loss

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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