Judul: Populasi Aspergillus flavus dan Kandungan Aflatoksin B1 pada Biji Kacang Tanah Mentah dan Produk Olahannya di Kecamatan Bogor Tengah, Kotamadya Bogor
Abstrak: This study was a survey to get information on the population of A. flavus and aflatoxin B1 content of raw peanut kernels collected randomly from retailers in two traditional markets (Pasar Anyar and Pasar Bogor) and five processed peanut products collected from retailers in Kecamatan Bogor Tengah, Municipality of Bogor. Physical quality of peanut kernels was only determined in raw peanut kernel samples. A total of 155 samples were collected. They consisted of 26 samples of raw peanut kernels and 129 samples of processed peanut products. As much as 14 and 12 samples of raw peanut kernels were collected from Pasar Anyar and Pasar Bogor, respectively. Processed peanut product samples consisted of roasted peanuts with skin pod (33 samples), flour-coated peanuts (33), siomay sauce (18), pecel/gado-gado sauce (33), and sate sauce (12). The highest percentage of intact kernels (70.6%) and the lowest percentage of damaged kernels (17.1%) were found in raw peanut kernels collected from Pasar Anyar. The highest percentage of shriveled kernels (12.7%) was found in raw peanut kernels collected from Pasar Bogor. Population of A. flavus in raw peanut kernels was much higher than that of in processed peanut products. Population of A. flavus in raw peanut kernels, roasted peanuts with skin pod, flour-coated peanuts, siomay sauce, pecel/gado-gado sauce, and sate sauce were 4 865.8, 0.3, 0.1, 0.3, 13.2, and 0.4 cfu/g (w. b.), respectively. The aflatoxin B1 content of raw peanut kernels was 43.2 ppb. The highest aflatoxin B1 content of processed peanut products (43.2 ppb) was found in roasted peanuts with skin pod, followed by flour-coated peanuts (34.3), sate sauce (23.2), pecel/gado-gado sauce (17.1), and siomay sauce (4.4).
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Judul: Serangan aspergillus flavus dan kontaminasi aflatoksin pada kacang tanah di grosir dan pengecer di pasar tradisional di kabupaten dan kota Cianjur, Jawa Barat
Abstrak: Penelitian ini merupakan survei yang bertujuan untuk memperoleh informasi mengenai penanganan pascapanen kacang tanah, serangan A. flavus dan kontaminasi aflatoksin B, pada 50 sampel kacang tanah yang diperoleh dari 2 grosir (5 sampel) dan 45 pengecer (45 sampel) di pasar tradisional di Kabupaten dan Kota Cianjur, Jawa Barat pada musim hujan bulan Februari 2004. Selain itu juga untuk mengetahui persentase biji yang terserang cendawan antagonisnya yaitu A. niger, kadar air dan kualitas fisik biji kacang tanah. Informasi mengenai penanganan pascapanen kacang tanah di grosir dan pengecer diperoleh dengan melakukan wawancara secara langsung menggunakan kuesioner. Hasil survei memberikan informasi bahwa kacang tanah di grosir diperoleh dari pengumpul, disimpan selama 1-2 bulan. Alas tumpukan karung kacang tanah tidak menggunakan palet. Kacang tanah di pengecer disimpan selama 1-7 hari, untuk wadah penjualan pada umumnya digunakan bak plastik persegi. Selain itu juga digunakan tampah, kotak kayu, bak plastik bundar, karung plastik plipropilena dan karung goni. Pengecer membeli kacang tanah dari grosir kecil, petani atau pengumpul. Rata-rata kadar air kacang tanah yang diperoleh dari grosir dan pengecer berturut-turut 7.5 dan 8.5%. Rata-rata persentase biji utuh, keriput dan rusak yang diperoleh dari grosir masing-masing adalah 63.6, 29.0 dan 7.4%, sedangkan dari pengecer masing-masing adalah 56.3, 29.0 dan 14.7%. Seluruh sampel kacang tanah yang diperoleh baik dari grosir maupun pengecer terserang oleh A. flavus, sedangkan sampel yang terserang A. niger pada kedua mata rantai distribusi lebih rendah yaitu masing-masing 60 dan 75.6%. Kisaran kandungan aflatoksin B, pada sampel yang diperoleh dari grosir (71.1-6 065.9 ppb) lebih sempit daripada yang diperoleh dari pengecer (<3.6-6 073.0 ppb). Seluruh sampel kacang tanah (100%) yang diperoleh dari grosir terkontaminasi aflatoksin B, lebih dari 15 ppb, sedangkan di pengecer 75.6%. Pada tahun 1999 Codex Alimentarius Commission menetapkan kandungan aflatoksin total pada kacang tanah yang akan diproses adalah 15 ppb.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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