Judul: The Quality Changes of Katokkon Chili (Capsicum annuum L. var. chinensis) Seeds during Short-Term Storage under Different Storage Conditions and Packaging
Abstrak: Cabai Katokkon (Capsicum annuum L. var. chinensis) merupakan cabai lokal asal Toraja yang memiliki tingkat kepedasan tinggi dengan aroma yang unik. Budidaya cabai Katokkon lebih banyak dilakukan di dataran tinggi karena memiliki produktivitas yang lebih baik. Mutu benih yang digunakan perlu diperhatikan untuk menunjang produksi cabai Katokkon. Penyimpanan benih yang tepat merupakan salah satu cara yang dapat menjaga mutu suatu benih. Penelitian ini dilakukan untuk menentukan kondisi penyimpanan yang tepat untuk mempertahankan mutu benih cabai Katokkon. Penelitian dilaksanakan di Laboratorium Penyimpanan dan Pengujian Benih, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor, pada bulan Januari hingga Agustus 2023. Penelitian menggunakan metode rancangan acak lengkap pola tersarang dengan dua faktor perlakuan, yaitu kondisi simpan dan jenis kemasan. Kondisi simpan terdiri atas dua taraf, yaitu penyimpanan pada suhu 26,8 - 29,5 °C, RH 61 - 73% (ruang kamar) dan penyimpanan pada suhu 15,7 - 19,7 °C, RH 44 - 64% (ruang ber-AC). Jenis kemasan terdiri atas dua taraf, yaitu kemasan plastik polipropilen (PP) dan kemasan aluminium foil yang tersarang pada kondisi simpan. Benih diamati setiap dua minggu sekali selama enam bulan penyimpanan. Hasil penelitian menunjukkan bahwa kondisi penyimpanan dengan suhu 15,7 - 19,7 °C; RH 44 - 64% (AC) lebih baik dalam mempertahankan mutu benih cabai Katokkon dibandingkan penyimpanan pada suhu 26,8 - 29,5 °C; RH 61 - 73% (kamar) terutama pada parameter kadar air, daya berkecambah, potensi tumbuh maksimal, indeks vigor, kecepatan tumbuh, dan keserempakan tumbuh. Aluminium foil dan plastik polipropilen dengan ketebalan 0,08 mm memiliki kemampuan mempertahankan kadar air yang tidak berbeda. Pada dua kemasan tersebut kadar air meningkat hingga mencapai kadar air kesetimbangan 9,89 - 10,95% pada suhu 26,8 - 29,5 °C; RH 61 - 73% (kondisi kamar) dan 9,45 - 10,05% pada suhu 15,7 - 19,7 °C; RH 44 - 64% (AC)., Katokkon chili (Capsicum annuum L. var. chinensis) is a local chili variety from Toraja known for its intense spiciness and distinctive aroma. The cultivation of katokkon chili is primarily carried out in the highlands due to its higher productivity to meet the increasing demand. Moreover, ensuring the seed quality is essential to support the production. Therefore, maintaining seed quality in proper storage condition is crucial. This research aimed to determine the proper storage conditions to maintain the quality of Katokkon chili seeds. The research was carried out at the Seed Storage and Testing Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University, from January to August 2023. The experiment was arranged in nested design with two factors. The first factor was two storage conditions, i.e., storage at temperature 26.8 – 29.5°C; RH 61 - 73% (ambient condition) and storage at temperature 15.7 – 19.7°C; RH 44 - 64% (air-conditioned room). The second factor was two packaging materials, i.e., polypropylene (PP) and aluminum foil nested into storage conditions. Seed quality was observed every two weeks for six months of storage. The study found that storage at temperature 15.7 - 19.7°C; RH 44 - 64% maintained seed quality better than storage at temperature 26.8 – 29.5°C; RH 61 - 73% as shown by moisture content, germination, maximum
Keyword: dormancy, seed deterioration, storability, viability, vigor

Judul: Perubahan Mutu dan Masa Simpan Cabai Katokkon (Capsicum annuum var. chinensis) dalam Berbagai Suhu Penyimpanan
Abstrak: Cabai katokkon memiliki laju penurunan mutu yang tinggi akibat peningkatan proses respirasi dan transpirasi jika disimpan dalam suhu ruang. Alternatif penanganan diperlukan untuk menekan penurunan mutu selama penyimpanan. Alternatif yang dapat digunakan adalah penyimpanan dingin. Tujuan penelitian ini adalah menganalisis pengaruh suhu penyimpanan terhadap mutu dan umur simpan cabai katokkon. Tahapan penelitian terdiri dari persiapan sampel, penyimpanan dalam suhu 5 °C, 10 °C, 15 °C dan suhu ruang (27 – 31 °C), pengukuran parameter mutu, serta pendugaan umur simpan. Parameter mutu yang diukur yaitu kadar air, nilai kekerasan, perubahan warna, dan tingkat kerusakan. Pendugaan umur simpan dihitung menggunakan metode Arrhenius dengan persamaan k = 19717162,36 e^-5803,8(1/T). Hasil penelitian menunjukkan penyimpanan cabai katokkon dalam suhu 5 °C menghasilkan rata-rata nilai kadar air tertinggi (91,32 %), nilai kekerasan tertinggi (0,51 kgf), laju kerusakan terendah (1,25 %/hari), dan dapat mempertahankan warna dan kecerahan cabai katokkon paling baik. Penyimpanan suhu ruang menghasilkan rata-rata nilai kekerasan terendah (0,44 kgf), laju kerusakan tertinggi (7,94 %/hari) dan dapat mempertahankan warna dan kecerahan cabai katokkon paling buruk. Penelitian ini menunjukkan bahwa penyimpanan cabai katokkon dalam suhu 5 °C memberikan hasil terbaik dalam memperpanjang umur simpan, menekan laju kerusakan, penurunan kadar air, nilai kekerasan, dan perubahan warna., Katokkon chili has a high rate of deterioration due to an increase in the process of respiration and transpiration when stored at room temperature. Alternative treatment is needed to reduce quality loss during storage. An alternative that can be used is cold storage. The purpose of this study was to analyze the effect of storage temperature on the quality and shelf life of katokkon chili. The research stage consists of sample preparation, storage at temperatures of 5 °C, 10 °C, 15 °C and room temperature (27 – 31 °C), measurement of quality parameters, and estimation of shelf life. The quality parameters measured are water content, hardness value, color change, and rottenness level. Estimation of shelf life calculated using the Arrhenius method with the equation k = 19717162,36 e^-5803,8(1/T). The results showed that the storage of katokkon chili at a temperature of 5 °C resulted in the highest average water content value (91.32 %), the highest hardness value (0.51 kgf), the lowest rottenness rate (1.25 %/day), and can maintain the color and brightness of the katokkon chili the best. Storage at room temperature resulted in the lowest average hardness value (0.44 kgf), the highest rottenness rate (7.94 %/day) and the worst color and brightness of katokkon chilies were maintained. This study showed that the storage of katokkon chili peppers in a temperature of 5 °C provides the best results in extending shelf life, suppressing the rate of rottenness, decreased moisture content, hardness value, and color changes.
Keyword: katokkon chili, quality, shelf life, storage, temperature

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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