Judul: Aktivitas Antioksidan dan Komponen Bioaktif Hidrolisat Protein Jeroan Ikan Kakap Putih (Lates calcalifer)
Abstrak: Visceral of barramundi (Lates calcalifer) is waste in the company of fisheries which has not been optimized so that making it potentially to be the product of protein hydrolysate. The purpose of this study is to make the protein hydrolysate from visceral of barramundi as antioxidant compounds. The method used was the optimization enzyme, hydrolysis time, and pH; proximate analysis, amino acids, antioxidant activity, and bioactive components. The condition of the highest antioxidant activity of visceral barramundi protein hydrolysate on the concentration of enzyme 0.1%, hydrolysis times 4 hours, and pH 7. The result of products contain water content (6.83%), ash (5.18%), protein (80.88%), fat (0.78%), and carbohydrate (13.15%). This product consists of 15 kinds of amino acids, which that 8 are essential amino acids and 7 are nonessential amino acids. Glutamic acid is an amino acid with the highest levels (8.71%), while an amino acid with the lowest levels is histidine (1.38%). This product show the antioxidant activity with IC50 value amounting to 1 048.40 ppm, and containing 5 from 9 bioactive components, among them flavonoid, carbohydrate, reducing agent of sugar, peptide, and free amino acids.
Keyword: protein, hydrolysate, bioactive, antioxidant, amino acid

Judul: Produksi dan Karakterisasi Hidrolisat Jeroan Ikan Kakap Putih (Lates calcarifer)
Abstrak: Viscera of Barramudi are low quality raw materials or waste, which might environmental and health problems if it’s not utilized. Barramudi viscera have high protein value (31.20%±0.33 bk) and fat (61.44%±1.22 bk). The fat content effects the process hydrolysis, so it requires process of disposal fat (deffating). Process deffating can reduce fat content from 61.44%±1.22 (bk) into 58.71%±0.65 (bk). Hydrolysis barramudi viscera using enzyme papain with activity 30 usp/mL. Optimal concentration of papain used for hydrolisis of barramudi viscera protein is 0.15% with hydrolisis time for 4 hours, temperature 55°C and pH 8. Characteristic products hydrolysates barramudi viscera (Lates calcarifer) has the water content (10.82%±0.84); ash content (7.30%±0.03); protein content (62.85%±0.72); fat content (0.84%±0.28); and carbohydrate (18.19%±1.32); protein digestibility (87.03%). Hydrolysates protein viscera barramundi has 15 content of amino acid, the highest and lowest amino acid, respectively, glutamic acid (10.75%) and histidine (1.38%). Hidrolisat protein can be applied as a source of protein in fish feed.
Keyword: papain., hydrolysates, fish viscera, deffating

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik