Judul: Regulasi Tipe Impeler dan Laju Pengadukan Hidrolisis Enzimatik pada Minyak Ikan untuk Produksi Monoasilgliserol Omega 3
Abstrak: Enzymatic Hydrolyse of fish oil in omega-3 monoaxylglycerol estabilishment using stirred tank affected by impeller type and stirring speed. This study aims to determine the type of impeller and stirring speed to produce the highest rate of hydrolysis which affects on the production of omega 3. This research was objected to determine impeller type and stirring rate which were able to generate highest hydrolysis level in anaerobe stirred tank reactor. The other purpose was to explain relationship between hydrolysis level and omega–3 total yield. The reaction performance was applied in anaerobe condition with tank impeller put in center position. The result showed that using radial impeller would increase the hydrolyse reaction when the stirring speed increased. Use of axial impeller had hydrolyse reaction result higher than radial impeller but higher speed of axial impeller stirring would decreased the hydrolyse reaction because of damaged enzyme. The data showed that axial impeller gave the highest hydrolysis level in low stirring rate compared to radial impeller. The highest hydrolysis level was obtained in axial type was 64.32% in stirring rate of 500 rpm with reaction rate of 7.58 %, while in radial type was 63.81 % in stirring rate of 700 rpm reaction rate of 5.78 %. The Omega–3 fatty acid concentration in media brought reached was 3.20% by radial impeller, whereas by axial impeller was 2.70 %. Whole omega–3 total in media was eicosapentaenoic acid (EPA). Justified by GC-MS.
Keyword: stirred tank., omega–3, lipase, hydrolysis

Judul: Kajian Hidrolisis Enzimatik Minyak Ikan untuk Produksi Omega-3 Menggunakan Lipase dari Aspergillus niger pada Media yang Ditambahkan Toluena
Abstrak: Omega-3 is an essential fatty acid that is needed for our brain and other organs development. Our body could not produce omega-3 itself, so we should consume it from our food. Omega-3 is found mostly from sea fish that eat phytoplankton that can produce omega-3 within their body. Many researches had been done to find an effective and efficient way to extract omega-3 from fish oil through hydrolysis, esterification, interesterification, acidolysis, or transesterification reaction. Omega-3 is usually produced in these three common forms: methyl ester, free fatty acid and acylglycerol. Acylglycerol form is considered better as food chemical material because it is easily digested by human digestive system. Selection of lipase as catalyst of hydrolysis reaction because of its easiness to get, it does not need cofactor, its stability and tolerance with solvent. Organic solvent could modify the original form of enzyme, so that it could change catalytic efficiency and specificity of enzyme. This research had aim to get reaction factor condition that could produce the best degree of hydrolysis of fish oil in a media without and with toluene-added media. Besides, this research’ aim was to figure out the correlation between optimum degree of hydrolysis of fish oil and sum amount of omega-3 fatty acid. The variations of factor reaction those were used here were temperatures (25-65)o Enzymatic hydrolysis of fish oil in this research was used a no-toluene-added media and a toluene-added media. Factors those were analyzed in hydrolysis in a no-toluene-added media are temperature and pH treatment. Factors those were analyzed in hydrolysis in a toluene-added media are water addition, pH and temperature treatment. Parameter that was used here to determine the effect of each factor was degree of hydrolysis. C, pH (5-9) and water addition (1-5)%v/v. Highest degree of hydrolysis in media without toluene addition on temperature treatment was 6,02% that was reached at 45o In water addition treatment, there were no significant effects of degree of hydrolysis for every stage of water addition. Otherwise, there was significance of degree of hydrolysis was decreasing. In pH treatment, degree of hydrolysis was decreasing while the value of pH was increasing. When it was reached pH 7, degree of hydrolysis had reached stationer phase for another stage of pH. C, while on pH treatment was 23,42% that was reached on pH 5. Highest degree of hydrolysis in media with toluene addition in a media with toluene addition on water addition treatment was 15,69%, while on pH treatment was 10,66% and on temperature treatment was 11,59%. According to the result of GC-MS analysis, highest omega-3 content was reached from enzymatic hydrolysis in a media without toluene addition on pH 5, whereas its EPA content was 12,43% and its DHA content was 0,86%. Omega-3 content in the result of enzymatic hydrolysis in a media with toluene addition consist of EPA content of 3,01% and DHA content undetected. Toluene addition into hydrolysis media could not increase the catalytic activity of Aspergillus niger lipase. So, it is better to hydrolyze fish oil with Aspergillus niger lipase in a no-toluene-added-media to reach higher degree of
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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