Judul: Pengemasan atmosfer termodifikasi pada jamur merang (Volvariella volvacea) blansir
Abstrak: Straw mushroom has a shelf life of 12 hours if left at room condition. This condition can be fixed by modified atmosphere packaging (MAP) application. The aim of this research was to obtain the best package design for modified atmosphere packaging of blanching straw mushroom. Before packaging, mushrooms treated blanching using hot water that serves to reduce the possibility of oxidation reactions. The addition of preservative aims to slow and inhibit the browning process of destructive microorganism, slow down, cover up or withhold the process of fermentation, putrefaction, acidification or other decomposition of destructive microorganism. Design of the package consisted of package size, number of perforation, and diameter of perforation. This research was also aimed to determine the best storage temperature. The parameters that observed during storage time were weight decrease, hardness, whiteness level, and the level of distortion. Each treatment had different perforation number and storage temperature. Perforation number that observered were 2, 4 and 8. Perforation diameter that used was 5 mm. While storage temperature that used were 5°C, 15°C, and 25°C. Each treatment made to twice repetition and stored for 14 days. The analysis done every 2 days. Every broken sample was not physically analyzed. During storage time weight, hardness, color, and quality decrease of straw mushroom is had happened thoroughly. Each package treatment had different effect on measured parameter. The result showed that package design of polypropylene plastic bag with 4 perforations and 5 mm perforation diameter that storaged in 15°C temperature was the best design to pack fresh straw mushroom. This package design was able to maintain mushroom quality for 10 days long, whereas other treatments were only able to maintain mushroom quality less than 10 days long. That package design was able to create optimum atmosphere compotition to pack mushroom so metabolism rate could be suppressed. Else, low storaging temperature could also suppressed metabolism rate as well as inhibited the growth of destructive microorganism. The result of mushroom measuring in that package at 10th day were weight decrease of 19:22%, hardness of 12.53 mm, whiteness level of 68.9, the level of damage by 38.49%. The damage indication that suffered by straw mushroom so it unable to consume were mushroom changed in color to brown, flabby and had decomposed smell.
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Judul: The Storage of Oyster Mushroom (Pleurotus ostreatus) with Modified Atmosphere Packaging in Various Types of Packaging
Abstrak: Jamur tiram putih merupakan salah satu produk pertanian yang mudah rusak sehingga dibutuhkan penaganan pascapanen yang baik. Tujuan penelitian ini adalah merancang pengemasan secara atmosfir termofifikasi (modified atmosphere packaging, MAP) dan mengkaji pengaruh pengemasan MAP terhadap mutu jamur tiram putih selama penyimpanan jamur. Penelitian meliputi pengukuran laju respirasi, perancangan pengemasan MAP dan pengamatan mutu jamur pada kemasan MAP selama penyimpanan. Pengukuran respirasi dilakukan menggunakan metode closed system. Jamur tiram seberat 250 g dimasukkan ke dalam stoples volume 3300 ml, ditutup rapat dan disimpan pada suhu 5, 10, dan 28 ℃ kemudian diamati perubahan gas O2 dan CO2 pada jam ke 2 dan 4. Laju respirasi dihitung berdasarkan perubahan konsentrasi gas, perubahan waktu, volume bebas dan berat sampel. Perancangan kemasan MAP dilakukan dengan simulasi berdasarkan data laju respirasi, permeabilitas kemasan, ukuran kemasan dan berat sampel untuk mendapatkan komposisi gas di dalam kemasan yang sesuai dengan yang direkomendasikan. Jenis kemasan MAP yang digunakan adalah polypropylene (PP), low density polyethelene (LDPE) dan stretch film. Pengamatan mutu jamur selama penyimpanan meliputi kadar air, susut bobot, kekerasan, warna dan total padatan terlarut. Hasil penelitian menunjukkan laju respirasi jamur dipengaruhi oleh suhu penyimpanan dimana laju respirasi meningkat dengan meningkatnya suhu penyimpanan. Hasil simulasi dalam perancangan kemasan MAP diperoleh berat jamur 60 gram pada kemasan jenis PP dengan ketebalan plastik 0.009 mm, luas permukaan 0.0144 m2, sedangakan kemasan LDPE diperoleh berat produk 150 gram, luas kemasan 0.0216 m2 dan ketebalan 0.02 mm, dan untuk kemasan stretch film diperoleh berat produk 200 gram, luas kemasan 0.0216 m2 dan ketebalan 0.01 mm. Kondisi gas pada semua kemasan dibuat dengan konsentrasi gas O2 dan CO2 sebesar 5-10%. Pengemasan MAP berpengaruh terhadap mutu jamur berdasarkan parameter pengamatan mutu susut bobot, kadar air, total padatan terlarut, kekerasan dan warna. Pengemasan MAP pada jamur tiram putih menggunakan plastik jenis stretch film memberikan hasil terbaik dan mampu mempertahankan masa simpan hingga 14 hari.
Keyword: MAP, oyster mushroom, packaging

Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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