Judul: Optimisasi Kombinasi Hot Water Treatment Dan Cacl2 Menggunakan Response Surface Methodologi Pada Mangga Gedong Gincu (Mangifera Indica L.)
Abstrak: Kendala utama dalam pascapanen produk hortikultura adalah bagaimana mempertahankan kualitas, sehingga dapat dipasarkan dengan jangkauan yang lebih luas. Penyebab utama kerusakan buah mangga adalah adanya hama dan investasi penyakit serta kondisi lingkungan yang dapat memicu percepatan metabolisme buah. Penelitian ini bertujuan untuk mendapatkan kombinasi perlakuan yang optimal dari tiga jenis perlakuan yaitu suhu HWT (Hot Water Threatment), lama ekspos buah pada suhu HWT dan perendaman buah setelah HWT ke dalam larutan CaCL2. Parameter kualitas yang diuji meliputi susut bobot, kekerasan, total padatan terlarut, keasaman (pH) dan croma. Untuk mendapatkan kombinasi optimum data dianalisis menggunakan metode RSM (Respon Surface Methode). Hasil analisis RSM pada penyimpanan 13 °C menunjukkan bahwa penurunan bobot buah dipengaruhi oleh suhu, lama perendaman pada HWT, dan lama perendaman pada larutan CaCl2. Hasil penelitian menunjukkan bahwa minimisasi penurunan bobot sebesar 2.18% diperoleh pada kombinasi perlakuan suhu ekpos 45.5 °C, lama ekpose 32 menit dan lama perendaman 38 menit. Pada kondisi ini diperoleh nilai kekerasan 1.02 Newton, Total Padatan Terlarut 16.8 oBrix, pH sebesar 5, Total Asam 0.003322 mg/100 gram, Croma 42.32. Sedangkan penyimpanan buah pada suhu 8 °C tidak dianjurkan karena hasil penelitian menunjukkan selama penyimpanan, buah mengalami gejala chilling injury dengan indikasi yang paling terlihat yaitu buah gagal matang dan warna buah tidak berubah semestinya dengan indikator buah berubah menjadi kecoklatan.
Keyword: RSM, HWT, mangga, pascapanen, susut bobot

Judul: Kajian Kombinasi Hot Water Treatment (HWT) dan CaCl2 terhadap Mutu dan Umur Simpan Mangga Varietas Gedong Gincu (Mangifera indica, L.)
Abstrak: Mango cv. gedong gincu is one of tropical fruit that has been a long time cultivated and have the commercial potention in Indonesia, but the export volume of this fruit is lower than the production volume. This is because of the quality, certification and limited of product supply. To increase the amount and competitivness of mango cv. gedong gincu’s export, there are some postharvest treatment, one of them is combination of hot water treatment (HWT) and CaCl2. General purpose of this research was to maintain tropical fruit quality starts from postharvest handling in the suply chain that already exist using the combination treatment. The research was divided into 4 main groups: preparation, treatment, observation and analysis the data. Through the research, treatment of HWT was significantly influencing the respiration rate, hardness, total soluble solids, weight losses and total acid; CaCl2’s soaking was not too influencing the changes of the fruit quality; and the combination treatment was significantly influencing the respiration rate, hardness, color changes and total acid of the fruit. From the visual, observation of quality changes and organoleptic test, sample of HWT 55oC 15’ (CaCl2 20’, 40’, 60’) have the most significant different value compared to another treatment. The longest storage period of the mango was sample with HWT 35oC; CaCl2 60’ and HWT 45oC 40; CaCl2 20’ that could be stored for 14 and 15 days based on respiration rate and total acid. The shortest storage period was sample with HWT 55oC 15’ (CaCl2 20’, 40’, 60’), 3 days.
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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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