Judul: Pendugaan sisa umur simpan kerupuk ikan tenggiri (Cybium comersoni) di pasaran
Abstrak: Salah satu cara mengolah ikan tenggiri adalah dengan mengubah bentuk ikan tenggiri menjadi produk kerupuk. Pengolahan ikan tenggiri menjadi kerupuk merupakan salah satu usaha untuk mengatasi pendeknya umur simpan ikan tenggiri segar. Penelitian ini bertujuan untuk memperoleh data perubahan mutu kerupuk ikan tenggiri dengan kemasan Polyprophylene (PP) dan High Density Polyethylene (HDPE) pada suhu penyimpanan yang berbeda selama jangka waktu tertentu serta menentukan sisa umur simpan kerupuk ikan tenggiri pada kemasan dan suhu penyimpanan yang berbeda. Parameter mutu yang diuji untuk menentukan sisa umur simpan produk adalah kadar air, kerenyahan dan kadar asam lemak bebas. Titik kritis yang didapat dengan melakukan uji penerimaan oleh panelis adalah kadar air kritis (4,5%), kerenyahan kritis (1,1 N) dan kadar asam lemak bebas kritis (0,928%). Kadar air kerupuk ikan tenggiri selama penyimpanan mengalami peningkatan pada kedua jenis bahan kemasan. Laju peningkatan (k) kadar air kerupuk ikan tenggiri pada suhu ruangan (25oC) dalam kemasan PP adalah 0,0506% per hari dan untuk kemasan HDPE adalah 0,0578% per hari. Kerenyahan kerupuk ikan tenggiri berkaitan dengan nilai kadar air. Kerupuk ikan tenggiri selama penyimpanan mengalami peningkatan nilai kekerasan pada kedua jenis bahan kemasan. Semakin besar nilai kekerasan maka semakin berkurang kerenyahan kerupuk ikan tenggiri tersebut. Laju penurunan (k) kerenyahan kerupuk ikan tenggiri pada suhu ruangan (25oC) dalam kemasan PP adalah 0,0113 N per hari dan untuk kemasan HDPE adalah 0,0176 N per hari. Kadar asam lemak bebas kerupuk ikan tenggiri selama penyimpanan mengalami peningkatan pada kedua jenis bahan kemasan. Laju peningkatan (k) kadar asam lemak bebas kerupuk ikan tenggiri pada suhu ruangan (25oC) dalam kemasan PP adalah 0,0045% per hari dan untuk kemasan HDPE adalah 0,0050% per hari
Keyword: Kerupuk ikan Tenggiri, PP, HDPE, Sisa Umur Simpan, Bogor Agricultural University, Institut Pertanian Bogor, IPB

Judul: Pendugaan Sisa Umur Simpan Kerupuk Ikan Tenggiri (Cybium commersoni) di Pasaran.
Abstrak: One of the ways to process mackerel is transform mackerel into cracker product. Processing mackerel into cracker product is one of effort to handle the short shelf life of mackerel. This research intent for getting data of mackerel cracker change quality with Polyprophylene (PP) packaging material and High Density Polyethylene (HDPE) on different storage temperature during certain time period and determine shelf life remainder on different pack and storage temperature. Quality parameter that has been tested in this reserch to determine the shelf life remainder of a product were moisture content, crispnes, abd free fatty acid content. Critical point was conducted in hedonic test on panelist, the points as follows : critical moisture content (4,5%), critical crispness (1,1 N), and the critical of free fatty acid content (0,928%). The moisture content of mackerel cracker during storage was increased on two kind of packaging. Increased rate (k) of moisture content for mackerel cracker (temperature of 25oC) in PP packaging material is 0,0506% per day and for HDPE packaging material is 0,0578% per day. The crispness of mackerel cracker related to moisture content value. The value of hardness was increasing during storage. The value of crispness was decreasing in order to the increasing value of hardness. The decreased rate (k) of crispness for meckerel cracker (temperature of 25oC) in PP packaging material is 0,0113 N per day and for HDPE packaging material is 0,0176 N per day. The free fatty acid content of mackerel cracker during storage was increased on two kind of packaging. Increased rate (k) of free fatty acid content for mackerel cracker (temperature of 25oC) in PP packaging material is 0,0045% per day and for HDPE packaging material is 0,0050% per day. The critical parameter from the mackerel crisps shelf life remainder estimation was crispness. The shelf life remainder based on that critical parameter was 58 days for mackerel cracker in PP pack and 37 days for mackerel cracker in HDPE pack. From the data could be known that mackerel cracker has shorter shelf life remainder than shelf life that atthaced by producer, which is 3 months.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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