Judul: Kajian Hidrolisis Enzimatik Minyak Ikan Untuk Produksi Omega-3 Menggunakan Enzim Lipase Aspergillus niger Pada Media Yang Ditambahkan Heptana.
Abstrak: Nowadays, the processing of sardine fish was as canned fish. The Waste was solid waste and fish oil which discarded and unusable further. However, this waste contains Omega-3. Omega-3 fatty acids were considered of essential for normal growth. It might be an important role to in the prevention and treatment of coronary artery disease, hypertension, arthritis, other inflammatory and autoimmune disorders, and cancer (Shahidi et al., 1998). Omega-3 was polyunsaturated fatty acids (PUFAs) contains long chain carbon double bound. Concentrate omega-3 was done by selective hydrolysis in sn-1 and sn-3 glyceride to produce sn-2 glyceride greatly in omega-3 using enzyme lipase from Aspergillus niger yeast. According Bockisch (1993), in the majority of fish oil triglycerides, PUFAs were bound to the 2-position of the glyceride backbone. Enzymatic hydrolysis was produce acylglycerol from triacylglycerol using water as reactant and enzyme as catalyst. Some studies indicate that PUFA were most promptly absorbed from the intestines when FFA was given orally, were moderately absorbed as acylglycerols and were poorly absorbed as PUFA ethyl ester (Carvalho et al., 2009). Organic solvent hydrofobic could be used as medium in the hydrolysis reaction to increased activity and stability enzyme. Even if, it increased substrat selectivity. Solvent hydrophobic heptane almost used as media to increased activity and stability due to it hydrophobocity at the range 2<log p<4. This research aims to determined reaction factor condition that could produce maximum degree of hydrolysis of fish oil in media without or with added-heptane media. Besides, it determined the correlation between maximum degree of hydrolysis of fish oil and sum amount of omega-3 fatty acid. The step of this research are characterize fish oil, calculate Activity enzyme (unit), and determine correlation between reaction parameter such as temperature, pH, and water addition as basis optimum condition for hydrolysis enzymatic in added-heptane media. Temperature, pH and water content used in this research are 25oC-65oC, 5-9, and 1%-5% respectively. Degree of hydrolysis showed catalytic activity enzyme to the ester bound triacylglycerol. Procedure of this research started with do enzymatic hydrolysis fish oil and do hydrolysis fish oil on the medium heptane. Analysis include acid value, saponification value, and GC MS measurement. Fish oil in this research had acid value and saponification value as much 3,26 and 204,81 respectively. Fish oil contain 34,98% unsaturated fatty acid include omega-3 as big as 1,81%,22,76% saturated fatty acid, alkana (11,19%), aldehid (0,88%), squalene (4,8%) and lanosterol (24,96%). Unit activity from the spectrophotometry measurement was 7939 U/g. Optimum condition according to the enzymatic hydrolysis were pH 5 and 45oC. The degree of this condition was 28,07%. According to the enzymatic hydrolysis in added heptane media, water addition optimum is 1% with the 26,16% degree hydrolysis. By using this optimum condition (pH 5, temperature 45oC, and water addition 1%), enzymatic hydrolysis in organic solvent were done. Heptane used as organic solvent media. According to this 5 research, in every point of temperature, the degree of hydrolysis increased except at 65oC due to denaturation of protein enzyme at 65oC. Temperature optimum for hydrolysis enzymatic in the organic solvent heptane was 25oC. According to
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Judul: Kajian Hidrolisis Enzimatik Minyak Ikan untuk Produksi Omega-3 Menggunakan Lipase dari Aspergillus niger pada Media yang Ditambahkan Heksana.
Abstrak: Nowadays utilization of sea fish is limited for human consumption only. This is made solid waste and fish oil that is produced during the process could not be utilized further. Besides, fish oil is the source of important fatty-acid, especially polyunsaturated fatty acid (PUFA) omega-3, those are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These kinds of fatty acids have important roles in fulfilling human nutrition, preventing and curing few diseases. Omega-3 fatty acid in acylglycerol form is considered better as food chemical form because it is digested easily by human digestive system. Production of omega-3 fatty acid in acylglycerol form with high products could be reached through enzymatic hydrolysis reaction. Aspergillus niger lipase has positional specificity that could break down triacylglycerols chain on stereochemical numbering position (sn) 1 and 3. Usage of this lipase in hydrolysis reaction could produce a lot of omega-3 fatty acid, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Catalytic activity of Aspergillus niger lipase is low when it is used in hydrolysis reaction of fish oil. That is the reason that it is needed to find a way to increase catalytic activity of Aspergillus niger lipase by adding organic solvent of hexane into its hydrolysis media. Besides, during hydrolysis process, activity and stability of enzyme is affected by environment condition, such as temperature, pH and water addition. This research had aim to determine reaction factor condition that could produce highest degree of hydrolysis of fish oil in a media without or with added-hexane media. Besides, this research aim was to determine the correlation between highest degree of hydrolysis of fish oil and sum amount of omega-3 fatty acid. The variation of factor reaction that was used here were temperatures (25-65)oC, pH (5-9), and water addition (1-5)%v/v. This research stage was began with fish oil characterization, measurement of activity of Aspergillus niger lipase with spectrofotometri method, enzymatic hydrolysis of fish oil in media without solvent addition, and hydrolysis in media with solvent addition using optimum temperature and pH from the result of hydrolysis in media without hexane addition. Analysis of end product was included measurement of degree of hydrolysis and gas chromatography mass spectrometry (GC-MS) analysis. Results of fish oil characterization of physiochemical characteristic showed that it had acid value of 3,26 mg KOH/g, free fatty acid content of 1,49%, and saponification value of 204,81 mg KOH/g. On the other hand, results of fish oil characterization of component analysis showed that it had saturated fatty acid content of 23,2%, unsaturated fatty acid content of 34,98%, alkenes 11,19%, squalenes 4,75%, aldehide 0,88% and lanol 24,96%. Result of measurement of activity of Aspergillus niger lipase was 7939,97 U/g.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf