Judul: The Effect of Drying Methods on  Pepsin Activity from Yellowfin Tuna Gastric (Thunnus albacares)
Abstrak: Pepsin merupakan enzim proteolitik yang aktif dalam kondisi asam. Bahan baku alternatif penghasil pepsin adalah lambung ikan tuna sirip kuning. Tujuan penelitian ini mengkarakterisasi enzim pepsin dari lambung tuna sirip kuning dan menentukan pengaruh pengeringan terhadap aktivitas enzim. Metode pengeringan yang digunakan, yaitu spray drying dan freeze drying. Aktivitas spesifik ekstrak kasar pepsin 19.982,52 U/mg, dengan Vmaks 50.000 mmol/s dan Km 0,5 mM. Pepsin optimum pada suhu 50°C dan pH 2, serta memiliki bobot molekul 32,837 kDa. Pepsin hasil spray dryer memiliki aktivitas spesifik 7693,5 U/mg, serta nilai Vmaks 833,33 mmol/s dan Km 0,5 mM, sedangkan hasil freeze dryer memiliki aktivitas spesifik 8606,75 U/mg, serta nilai Vmaks dan Km berturut-turut 1666,67 mmol/s dan 0,833 mM. Bobot molekul pepsin hasil pengeringan spray dryer 33,764 kDa dan freeze dryer 33,64 kDa. Hasil penelitian menunjukkan aktivitas spesifik pepsin menurun setelah proses pengeringan., Pepsin is a proteolytic enzyme that has the ability active in acidic conditions. The alternative raw material for pepsin is the stomach of yellowfin tuna. The purpose of this study was to characterize the pepsin enzyme from the stomach of yellowfin tuna and to analyze the enzyme activity after drying process. The drying method was used spray drying and freeze drying. The specific activity of pepsin crude extract was 19.982,52 U/mg, with Vmax 50.000 mmol/s and Km 0,5 mM. The optimum pepsin at 50oC temperature and pH 2, and has a molecular weight 31,837 kDa. The dried pepsin with spray drying has a specific activity 7693,5 U/mg, with Vmax 833,33 mmol/s and Km 0,5 mM, whereas with freeze drying has a specific activity 8606,75 U/mg, Vmax and Km values respectively 1666,67 mmol/s and 0,833 mM. The molecular weight of pepsin enzyme with spray drying 33,764 kDa and freeze drying 33,64 kDa. The results showed the specific activity of pepsin decreased after the drying process
Keyword: Aktivitas enzim, Pengeringan beku, Pengeringan semprot, Pepsin

Judul: Enzyme Trypsin Activity from Yellowfin Tuna (Thunnus albacares) with Different Drying Methods
Abstrak: Enzim telah banyak digunakan dalam berbagai proses kimiawi, baik dalam bidang industri maupun dalam bidang bioteknologi salah satunya yaitu enzim tripsin. Enzim tripsin dari jeroan ikan bisa menjadi alternatif dari enzim tripsin komersil yang berasal dari babi dan sapi. Tujuan penelitian ini adalah mengkarakterisasi enzim tripsin dan menganalisis pengaruh pengeringan terhadap karakteristik enzim tripsin yang dihasilkan. Metode pengeringan yang digunakan, yaitu spray drying dan freeze drying. Nilai aktivitas spesifik dari ekstrak kasar tripsin 0,053 U/mg, dengan nilai Vmaks 0,0050 mmol/s dan Km 0,405 mM. Enzim tripsin didapatkan optimum pada suhu 60°C dan pH 8, dan memiliki bobot molekul sebesar 29,346 kDa. Tripsin hasil pengeringan menggunakan spray dryer memiliki aktivitas spesifik 0,068 U/mg, serta nilai Vmaks 0,0018 mmol/s dan Km 0,808 mM, sedangkan dengan freeze dryer memiliki aktivitas spesifik 0,069 U/mg, serta nilai Vmaks 0,0041mmol/s dan Km 0,317 mM. Bobot molekul tripsin dengan pengeringan spray dryer sebesar 28,119 kDa dan freeze dryer 28,665 kDa. Hasil penelitian menunjukan bahwa aktivitas spesifik tripsin tidak berpengaruh nyata setelah proses pengeringan., Enzymes have been used in various chemical process, either in industry or biotechnology and one of them is trypsin enzyme. Enzyme from fish viscera could be used as an alternative of commercial trypsin from pig or cow. The purpose of this study was to characterize the trypsin enzyme and and to analyze the enzyme activity after drying process. The specific activity of trypsin crude extract was 0,053 U/mg, with Vmax value 0,0050 mmol/s and Km 0,405 mM. The optimum trypsin enzyme at 60oC and pH 8, and has a molecular weight 29,346 kDa. The dried trypsin with spray drying has a specific activity value 0,068 U/mg, with Vmax value 0,0018 mmol/s and Km 0,808 mM, whereas with freeze drying has a specific activity value 0,069 U/mg, Vmax value 0,0041 mmol/s and Km 0,317 mM. The molecular weight of trypsin enzyme with spray drying was 28,119 kDa and freeze drying was 28,665 kDa. The results showed the specific activity of trypsin had no significant effect after the drying process.
Keyword: Enzim tripsin, Aktivitas enzim, Ikan tuna sirip kuning, Spray dryer, freeze dryer

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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