Judul: Characteristics of Collagen from Pangas Catfish Swim bladder (Pangasius sp.) with Differences Time of Ultrasound
Abstrak: Gelembung renang merupakan hasil samping perikanan yang sebagian komponen utamanya berupa protein kolagen. Kolagen merupakan komponen struktural utama dari jaringan ikat. Penelitian ini bertujuan menentukan komposisi kimia, struktur jaringan gelembung renang ikan patin, proses ekstraksi, serta hidrolisis kolagen gelembung renang ikan patin dengan waktu sonikasi berbeda (0, 10, 15, dan 20 menit). Gelembung renang tersusun atas serat-serat yang menggelombang, memiliki percabangan serta memiliki ruang antar serat. Perlakuan terbaik dari kolagen gelembung renang ikan patin ditentukan berdasarkan analisis ANOVA dan uji lanjut Duncan. Kualitas hidrolisat kolagen terbaik diperoleh dari perlakuan waktu sonikasi 15 menit. Kolagen memperoleh rantai a_(1,) a_(2,) dan ß. Hidrolisat kolagen memiliki gugus fungsi dengan puncak serapan amida A, amida B, amida I, amida II, dan amida III, nilai pH 6,67±0,15, nilai viskositas 4,00±1,92, serta memperoleh aktivitas antioksidan dengan nilai IC50 44,09±0,48., The swim bladder is fishery by-product whose main components are collagen protein. Collagen is the main structural component of connective tissue. This research aims to determine the chemical composition, structure of catfish swim bladder tissue, extraction process, and collagen hydrolysis of catfish swim bladder with different sonication times (0, 10, 15, and 20 minutes). Swim bladder is composed of wavy fibers, have branches and have spaces between fibers. The best treatment of catfish swim bladder collagen was determined based on ANOVA analysis and Duncan's further test. The best quality of collagen hydrolysate was obtained from a sonication treatment time of 15 minutes. Collagen obtained a_(1,) a_(2,) and ß chains. Collagen hydrolysate had functional groups with peak absorption of amide A, amide B, amide I, amide II, and amide III, pH value of 6,67±0,15, viscosity value of 4,00±1,92, and antioxidant activity with IC50 value of 44,09±0,48.
Keyword: antioxidant, hydrolysis, moleculer weight, tissue structure, ultrasound

Judul: Karakteristik Hidrolisat Kolagen dari Kulit Ikan Patin (Pangasius hypophthalmus) dengan Perbedaan Konsentrasi Enzim Papain
Abstrak: Kolagen merupakan struktur protein kompleks yang diperoleh dari jaringan ikat. Pembuatan kolagen secara enzimatis menggunakan enzim papain akan memperoleh produk berupa hidrolisat kolagen. Penelitian ini bertujuan untuk menganalisis perubahan struktur jaringan pada kulit ikan patin sebelum dan setelah dilakukan pretreatment dan ekstraksi, serta menentukan karakteristik hidrolisat kolagen dengan perbedaan konsentrasi enzim papain (1%, 3%, dan 5%). Struktur jaringan kulit ikan patin sebelum pretreatment terlihat benang stratum compactum tebal, sedangkan setelah pretreatment dan ekstraksi terlihat benang stratum compactum terurai dan rusak. Hidrolisat kolagen memperoleh nilai derajat hidrolisis (72,37±1,86)-(97,22±3,93)%, nilai pH (6,23±0,12)-(7,22±0,08), dan nilai bobot molekul 12,016-23,877 kDa. Potensi aktivitas antioksidan yang diperoleh tergolong sangat kuat pada metode FRAP dan ABTS. Aktivitas antioksidan pada metode FRAP memperoleh nilai sebesar (536,31±2,61)(641,43±4,08) μmol Fe(II)/g, sedangkan pada metode ABTS memperoleh nilai sebesar (38,02±1,72)-(54,17±0,98) ppm., Collagen is a complex protein structure obtained from connective tissue. Enzymatic production of collagen using the papain enzyme will obtain a product in the form of collagen hydrolyzate. This study aims to analyze changes in the tissue structure of catfish skin before and after pretreatment and extraction, and to determine the characteristics of collagen hydrolyzate with different concentrations of papain enzymes (1%, 3%, and 5%). The structure of the catfish skin tissue before pretreatment showed thick stratum compactum threads, whereas after pretreatment and extraction, the stratum compactum threads were seen to be decomposed and damaged. Collagen hydrolyzate obtained a hydrolysis degree of (72.37±1.86)-(97.22±3.93)%, a pH value of (6.23±0.12)-(7.22±0.08), and a molecular weight value of 12.016-23.877 kDa. The potential antioxidant activity obtained is classified as very strong in the FRAP and ABTS methods. The antioxidant activity in the FRAP method obtained a value of (536.31±2.61)(641.43±4.08) mol Fe(II)/g, while the ABTS method obtained a value of (38.02±1.72)-(54.17± 0.98) ppm.
Keyword: antioxidant, collagen hydrolyzate, papain enzyme, structural change

Judul: Utilization of terra/MODIS L1B data for analysis of horizontal wind profile in the troposphere
Abstrak: This study was concerned with horizontal wind derived from data collected with the Moderate-resolution Imaging Spectroradiometer (MODIS) on board the NASA’s Earth Observation System (EOS)-Terra satellite. The aim of this study is to develop a method for the estimation of horizontal wind movement in the troposphere based on Navier-Stokes equation. The method was applied to a calibrated and geolocated Terra/MODIS L1B 1 km data set. The data inputs to estimate surface temperature are retrieved from TIR (Thermal Infrared) bands 31 (10.780 μm to 11.280 μm) and 32 (11.770 μm to 12.270 μm). The obtained surface temperatures were later used to approximate geopotential height on a constant-pressure surface by using the modified Poisson equation. The main assumptions used are the hydrostatic equilibrium, ideal gas law, constant lapse rate and constant acceleration of gravity. Based on the distribution of geopotential height, the pressure gradient force is measured by the gradient of geopotential on an isobaric coordinate to present the horizontal wind profile. For certain topographic areas especially in the mountain ranges, there was a disadvantage of using pressure as a vertical coordinate which lead to inaccuracy. In spite of that, Terra/MODIS L1B data with 1 km spatial resolution can be used to estimate the horizontal wind movement in the troposphere.
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