Judul: Aplikasi Response Surface Methodology untuk Optimasi Ekstraksi Gelatin dari Kulit Ikan Patin dan Pemanfaatannya sebagai Kapsul Keras
Abstrak: Kulit ikan patin sangat potensial menjadi sumber gelatin, namun proses ekstraksinya masih belum optimal. Penelitian ini bertujuan mengoptimasi proses ekstraksi gelatin dari kulit ikan patin dengan Response Surface Methodology (RSM) dan menggunakan gelatin yang didapat sebagai bahan baku kapsul keras. Rancangan eksperimen yang digunakan yaitu Central Composite Design (CCD) yang terdiri dari dua variabel yaitu konsentrasi asam sitrat dan waktu ekstraksi. Konsentrasi asam sitrat berkorelasi positif terhadap respon rendemen, kadar air, kadar abu, pH, viskositas, dan setting point sedangkan waktu ekstraksi berpengaruh terhadap rendemen, kekuatan gel, kadar air dan setting point. Interaksi kedua faktor ini mampu meningkatkan karakteristik gelatin. Ekstraksi yang optimal dengan konsentrasi asam sitrat 0.297% dan waktu ekstraksi 8 jam menghasilkan gelatin dengan kualitas yang telah sesuai dengan standar GMIA 2019 dan SNI 0637351995. Karakteristik kapsul yang dihasilkan telah sesuai dengan standar Departemen Kesehatan RI (1995). Hasil ini menunjukkan proses ekstraksi yang dilakukan mampu menghasilkan gelatin yang dapat digunakan sebagai bahan baku industri kapsul keras yang sesuai standar.
Keyword: catfish, gelatin, hard capsule, process optimization, RSM

Judul: Optimization Gelatin Extraction Process for Catfish (Pangasius sp.) Skin with Response Surface Methodology Application
Abstrak: Ikan patin merupakan bahan baku gelatin alternatif yang aman dan halal. Kulit ikan memiliki karakteristik yang berbeda dengan hewan terestrial sehingga memerlukan optimasi pada proses ekstraksi sebelum masuk ke skala industri. Penelitian ini bertujuan melakukan optimasi kondisi pretreatment pada proses ekstraksi gelatin menggunakan Response Surface Methodology (RSM) serta menentukan karakteristik gelatin terpilih. Rancangan eksperimen yang digunakan yaitu Central Composit Design (CCD) dengan dua variabel bebas (konsentrasi NaOH dan konsentrasi asam asetat) dan 7 variabel respon (rendemen, kadar air, kadar abu, kekuatan gel, viskositas, pH, dan setting point). Hasil optimasi diperoleh respon optimum pada konsentrasi NaOH 0,3 M dan konsentrasi asam asetat 0,067 M. Hasil validasi keadaan optimal memperoleh gelatin terpilih dengan rendemen 22,44±0,68%, kadar air 8,53±3,4%, kadar abu 0,325±0,22%, derajat keasaman (pH) 6,65±0,13, kekuatan gel 241,58±9,5 Bloom, viskositas 6,65±0,5 mPas, dan setting point 19,75±1,06 ℃. Karakteristik gelatin terpilih telah memenuhi standar gelatin SNI 8622:2018 dan GMIA 2019., Catfish is an alternative raw material for gelatin that is halal and safe. Pangasius skin has different characteristics from terrestrial animals, so it requires to optimize the extraction process before industrial scale production. This study aims to optimize the pretreatment conditions in the gelatin extraction process using the Response Surface Methodology (RSM) and determine the characteristics of the selected gelatin based on the pretreatment conditions. Central Composite Design (CCD) with two independent variables (NaOH concentration and acetic acid concentration) and 7 response variables (yield, moisture content, ash content, gel strength, viscosity, pH, and setting point) was performed. The results showed the optimum response at 0.3 M NaOH and 0.067 M acetic acid. The validation obtained selected gelatin with a yield 22.44 ± 0.68%, water content 8.53 ± 3.4%, ash content 00.325 ± 0.22%, degree of acidity (pH) 6.65 ± 0.13, gel strength 241.58 ± 9.5 Bloom, viscosity 6.65 ± 0.45 mPas, and setting point 19.75 ± 1.06 ℃. The characteristics of the selected gelatin have met the SNI 8622: 2018 and GMIA 2019 gelatin standards.
Keyword: catfish, gelatin, halal, process optimization, RSM

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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