Judul: Produksi Tepung Sukun (Artocarpus altilis) Pragelatinisasi
Abstrak: The fruit of breadfruit tree is one alternative carbohydrate source in Indonesia. Breadfruits is an important energy food contain starch and sugar, and usually consume as fresh fruit. However, breadfruit is seasonal crop and sometimes the crops are so plentiful that it can not be eaten fresh. To prevent waste, it was preserved in different way including drying. Flour from breadfruit can be used as important food for all seasons. Breadfruit flour has many limitations since it is difficult to be solubilized and swollen in cold water. The flour is modified physically by pregelatinization to improve its properties. Pragelatinized breadfruit flour can be used as instant food, porridge, and baby food. This research is aimed to investigate the effect of slurry concentration and contact time of the slurry on the drum. The process is conducted using double drum dryer with temperature of plate is 80±5C. Twenty and 30% of slurry were poured into drum with different rotation speed (4, 6 and 8 rpm). Each flour is characterized its chemical composition and physico-chemical properties. Generally pregelatinization did not influence to the chemical composition. Pregelatinization of the flour improved the water solubility and swelling power on room (30C) and hot (70C) solutions, reduced the freeze-thaw stability, caused partial gelatinization which is monitored by losing the birefringence of starch granule, and darkened the flour. The pregelatinized flour also reduced gelatinized temperature and had low final viscosity. Low concentration of slurry and low rotation speed of drum increased the gelatinized part of the flour, which is influenced to the cold and hot water solubility.
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Judul: Produksi tepung sukun (Artocarpus Altilis) pragelatinisasi
Abstrak: Sukun (Artocarpus altilis) dapat merupakan alternatif sumber karbohidrat, dan mempunyai nilai ekonomis cukup tinggi karena dapat dijual dalam bentuk segar maupun olahan sebagai alternatif pangan pengganti beras. Saat ini pemanfaatan buah sukun sebagai bahan makanan masih terbatas secara tradisional yaitu direbus, digoreng, dibuat keripik, dibuat kolak, dan difermentasi jadi tape. Terbatasnya pemanfaatan buah sukun disebabkan kurangnya informasi tentang komoditas sukun, sehingga upaya untuk meningkatkan daya guna sukun dan nilai ekonominya diperlukan usaha penganekaragaman jenis produk olahan sukun. Penelitian ini bertujuan untuk mengkaji proses produksi tepung sukun termodifikasi dengan mengamati pengaruh perbandingan konsentrasi tepung dan kecepatan putar drum dryer terhadap karakteristik sifat fisiko kimia dan fungsional dari tepung sukun pragelatinisasi yang dihasilkan. Tepung sukun termodifikasi dapat dimanfaatkan sebagai makanan instan, bubur dan makanan bayi. Modifikasi tepung menjadi tepung sukun pragelatinisasi memiliki tahapan proses yang harus dilakukan dengan seksama. Tahapan proses pengolahan tepung sukun pragelatinisasi ada tiga tahap, yaitu persiapan bahan, proses utama (pemanasan dan pengeringan), dan proses penggilingan. Persiapan bahan dilakukan terlebih dahulu dengan mencampurkan tepung sukun alami dengan air dengan perbandingan 20% dan 30% tepung dalam suspensi. Pada penelitian ini digunakan double drum drier dengan kecepatan putaran 4, 6 dan 8 rpm. Proses utama pengolahan tepung sukun pragelatinisasi terdiri atas pemanasan dan dilanjutkan dengan pengeringan pada suhu di atas suhu gelatinisasi yaitu 80±5°C pada double drum drier yang memiliki panjang dan diameter berturut-turut adalah 12 dan 8 inci…
Keyword: Pragelatinisasi, Tepung, Sukun, Bogor Agricultural University, Institut Pertanian Bogor, IPB

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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