Judul: Pengembangan Proses Pembuatan Gelatin dari Tulang Ikan Mackerel (Scomber scombrus)
Abstrak: Gelatin is collagen protein which exist in connective tissue, reversible, and mainly used in food industry as stabilizers or emulsifier. Gelatin in Indonesia is regularly imported from other countries, extracted and denatured from beef or pork bone. The main goal from the experiment is to find the extraction method of gelatin from mackerel fish bone and get the gelatin halal which meet the standard. Preliminary research are proximate analyse the mackerel fish bone and soaked the fish bone in chloride acid with different concentration and various time to adjust the best formula to lower the ash. The main research is to produce gelatin and proximate analyze the gelatin powder. Proximate analyze results that the best gelatin was produced by soaking the fish bone through chloride acid with 5% concentration during 2 hours having moisture 7.74%, ash 1.05%, fat 3.41%, protein 84.88%, and yield 2.42%. Gelatin yield is considered low because the fish type is low in collagen.
Keyword: Bogor Agricultural University (IPB), mackerel, gelatin, fish bone, chloride acid

Judul: Extraction and Characterization Gelatin of Seabass Skin (Lates calcalifer)
Abstrak: Gelatin merupakan jenis protein hasil konversi dari hidrolisis parsial kolagen. Industri gelatin umumnya banyak menggunakan tulang dan kulit sapi serta kulit babi yang diketahui tidak sesuai dengan keyakinan agama dan etnis tertentu. Oleh karena itu diperlukan alternatif sumber kolagen yang dapat diterima oleh semua agama dan etnis. Alternatif sumber kolagen tersebut salahsatunya adalah kulit ikan kakap putih namun informasi mengenai ektraksi dan karakteristik gelatin yang dihasilkan belum banyak diketahui sehingga diperlukan penelitian. Tujuan penelitian ini adalah untuk menentukan konsentrasi NaOH dan lama waktu perendaman terpilih, konsentrasi CH3COOH terpilih dan menentukan karakteristik gelatin yang dihasilkan dari perlakuan terpilih. Perlakuan terpilih yaitu perendaman dengan NaOH 0,05 M selama 8 jam dan CH3COOH 0,1 M selama 2 jam. Karakteristik gelatin kulit ikan kakap putih meliputi rendemen, pH, viskositas dan kadar air berturut-turut 10,94%; 6,96; 2,36 cP; 9,55%. Analisis spektra fourier transform infrared (FTIR) menunjukkan wilayah penyerapan utama amida A, B, I, II, dan III masing-masing pada 3321,16; 2937,29; 1647,64; 1533,33; dan 1240,83 cm-1 .
Keyword: FTIR, Gelatin, Ikan kakap putih, Rendemen, Viskositas, Hydrolyzed collagen, Gelatin industry, Naoh, CH3 COOH, Seabass skin, FTIR

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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