Judul: Pengemasan dan Penyimpanan Minuman Sari Jagung.
Abstrak: Corn especially sweet corn (Zea mays L. var. Saccharata Sturtev.) is one of basic foodstuffs which have an important position after rice for Indonesian society. This is because sweet corn can grow almost everywhere in Indonesia due to soil and climatic conditions appropriate, easily grown and maintained, rapid harvest, and good to eat. In some developed countries, sweet corn has been cultivated in various processed forms such as canned, frozen, and made cream, even the results of the extraction process into the so-called sweet corn juice or corn maize milk (corn milk). Sweet corn juice is a source of carbohydrates, calcium and has much lower fat content than soybeans. So eat sweet corn juice is very good as a source of energy, strengthens bones and for those who want to avoid high fat consumption. The purpose of this study was to assess changes in quality of sweet corn juice drinks that are packed with plastic cups of polypropylene and HDPE plastic bags, and stored at cold temperatures (3,5 + 1,5 oC and 12,0 + 2,0 oC) and at room temperature (27,5 + 2,5 oC). In addition, this study also aimed to determine the shelf life of sweet corn juice. First phase of the reaserch are the creation of the corn juice and the determination of its characteristics. Based on results from phase one research, the characteristics of corn juice is having ash content of 0.1405 %, 2.12 % protein, 2.53 % fat content, pH 6.86, TPC of 5.8 x 104 colonies / g products, and total solids 13 oBrix. The test results showed that the quality of the corn juice decreased during storage. The lowest pH changes are owned by the corn juice is packed with HDPE plastic bags and stored at 3,5 + 1,5 oC on the seventh day, i.e 3.25. The highest total acid value owned by the packaging of products that are packed with plastic cups of polypropylene at 27,5 + 2,5 oC on the third day, i.e 9.45 ml of NaOH 0.1 N/100 g. The highest value of total dissolved solids are owned by the corn juice that are packed with plastic cups of polypropylene and stored at 3,5 + 1,5 oC on the seventh day, ie 19.1 oBrix. Corn juice fastest caking is stored at temperature 27,5 + 2,5 oC, both packed with plastic cups of polypropylene or HDPE plastic bags, i.e on the third day. Based on the parameters of acceptance flavor, the best corn juice is to be packaged with a plastic cup of polypropylene at the temperature from 12,0 + 2,0 oC.
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Judul: Optimizing the Quality of Sweet Premix Corn Dog Flour Through Storage and Packaging Design Considering Water Activity
Abstrak: PT LeGitt Boga Mandiri sebagai perusahaan makanan berbasis tepung terigu telah menciptakan varian produk terbaru dari tepung premix yaitu tepung sweet premix corn dog. Menjaga kestabilan mutu pada produk perlu dilakukan dengan berfokus pada kondisi lingkungan penyimpanan produk dan kemasan yang digunakan. Pengujian isotermi sorpsi air dilakukan untuk mengetahui kenaikan kadar air pada bahan yang digambarkan menggunakan kurva isotermi sorpsi air (ISA). Dari kurva ISA tersebut dilakukan pembagian fraksi daerah air terikat dengan masing-masing batas atas pada daerah primer, sekunder dan tersier dengan nilai aktivitas air 0,09, 0,69 dan 1. Berdasarkan SNI 01-4476-1998, batas kadar air pada tepung sweet premix corn dog sebesar 12% dilampaui pada lingkungan penyimpanan dengan kelembaban relatif (RH) > 0,69% pada suhu 28oC. Uji cemaran mikroba juga dilakukan dengan diketahui adanya nilai angka lempeng total (ALT), kapang dan khamir dengan taraf aman. Untuk melindungi produk dari kenaikan kadar air yang dipengaruhi oleh lingkungan penyimpanan, maka digunakan jenis material kemasan Polyethylene (PE) dan papersack sebagai material kemasan terbaik yang tersedia di pasaran. Berdasarkan penentuan material kemasan maka dirancang 3 desain mock up kemasan. Hasil penilaian oleh 32 panelis menunjukkan bahwa desain mock up kemasan kedua (#2) memiliki nilai kepuasan tertinggi., PT LeGitt Boga Mandiri, a flour-based food company, created a new product variant called sweet premix corn dog flour. The company ensured product quality stability by focusing on product storage conditions and the packaging used. Water sorption isotherm testing was conducted to determine the increase in water content in the material, described using the water sorption isotherm (WSI) curve. From the WSI curve, the fractions of bound water in the primary, secondary, and tertiary regions were determined with respective upper limits at 0.09, 0.69, and 1 water activity values. According to the SNI 01-4476-1998 standard, the water content limit for sweet premix corn dog flour is 12%, which was exceeded when stored in an environment with relative humidity (RH) > 0.69% at 28°C. Microbial contamination tests were also conducted by determining the total plate count (TPC), mold, and yeast with a safe threshold. To protect the product from water content increases influenced by storage conditions, Polyethylene (PE) and papersack packaging materials were used as the best available options in the market. Based on the determination of packaging materials, three mock-up packaging designs were created. The evaluation results by 32 panelists showed that the second mock-up packaging design (#2) had the highest satisfaction score.
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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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