Judul: Sintesis Monolaurin Menggunakan Enzim Lipase Imobil Dengan Packed Bed Reaktor
Abstrak: Monoasilgliserol (MAG) adalah salah satu emulsifier yang banyak digunakan sebagai bahan tambahan pangan. MAG secara luas digunakan dalam produk bakeri, margarin, produk susu, dan confectionary karena sifat emulsifikasi, stabilisasi, dan conditioning. Salah satu jenis MAG, yaitu monolaurin, monogliserida dari asam laurat, merupakan salah satu produk turunan dari minyak, yang memiliki keistimewaan. Kegunaan monolaurin adalah sebagai bahan pengawet pangan dan sanitizer. Saat ini monolaurin sudah banyak digunakan dalam industri kosmetik, farmasi dan obat-obatan. Saat ini cara umum yang banyak digunakan industri untuk sintesis monolaurin adalah dengan bantuan katalis kimia (alkali). Namun metode ini memiliki beberapa kekurangan seperti jumlah produk yang dihasilkan rendah, produk berwarna gelap, serta diperlukannya suhu dan energi tinggi dalam prosesnya. Oleh karena itu dikembangkan metode esterifikasi dengan katalis enzim lipase yang dapat mengatasi kekurangan-kekurangan dari metode kimia. Melalui metode esterifikasi dengan katalis enzim, dihasilkan produk dengan kadar MAG mencapai lebih dari 80%. Penelitian ini mengkaji mengenai hubungan antara laju alir volumetrik dan waktu tinggal substrat pada packed bed reactor dengan yield MAG yang dihasilkan dari sintesis yang dikatalis oleh enzim lipase imobil Novozym 435. Hasil menunjukan waktu tinggal optimum untuk memperoleh produk dengan persentase monolaurin maksimum (89.47%) adalah 94 menit. Waktu tinggal optimum tersebut dapat diperoleh dengan mengatur laju alir volumetrik substrat sebesar 0.4272 mL/menit.
Keyword: monolaurin, Novozym 435, esterifikasi, packed bed reactor

Judul: Optimasi sintesis monolaurin menggunakan katalis enzim lipase imobil pada circulated packed bed reaktor
Abstrak: Monolaurin is a special food grade monogliceride, which has a function beside as emulsifier and food preservative, also has an ability to destroy Herpes and HIV-1 virus. It was reported that monolaurin had the greatest antimicrobial activity among monoglycerides. Novozyme® 435 catalyze the esterification of lauric acid and glycerol in organic solvent. The purpose of this research were : 1) to obtain optimum condition to synthesis monolaurin using Novozyme® 435; 2) to analyze the stability of Novozyme® Continuous circulated packed bed reactor had residence time of 23,57 minute, glycerol/ oil molar ratio of 5:1, solvent/substrate ratio of 8,8:1, and the process produced MAG up to 80%. Optimization of synthesis MAG obtained quadratic equation which was Y= - 61,700 + 6,088 x 435 in continuous system. Continuous Esterification was employed in circulated packed bed reactor. This research was using Response Surface Methods (RSM) as experimental design and temperature and time reaction were as variables. 1+3,259 x2 – 0,065 x12 + 0,017 x1x2 – 1,792 x22 with R2 = 0,5408, optimum temperature and time reaction of 46,92oC and 1,1 hour, respectively. The product yield was 81,09% and contained MAG of 83,15%. The product had acid value of 1,78±0,08 %, peroxide value of 0,49 ± 0,14 meq O2/kg MAG, free glycerol content of 0,26%, and melting point 53-53,5o C. The enzyme remain stable during 10 reaction cycles and up to 70% produced of MAG at each cycle
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Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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