Judul: Pengaruh Pelapisan Lilin dan Suhu Penyimpanan terhadap Masa Simpan Buah Naga Super Red (Hylocereus costaricensis)
Abstrak: Hylocereus costaricensis or super red dragon fruit has a short shelf life due to its withered scales that affects consumers‟ preference. Coating application and low temperature storage were expected to extend the shelf life. The aim of this research is to study the application of coating and the impact of its interaction with storage temperature on super red dragon fruit shelf life. Coating using cera alba wax with and without stearin as the substitution were applied in dragon fruits that then were stored at room temperature, 12oC, and 5oC. The analysis of scale freshness percentage, weight loss, firmness, and ion leakage were done every 2 days for room temperature and 7 days for low temperature. The result showed that dragon fruits could be stored for 4 days at room temperature, 14 days at 12oC, or 21-28 days at 5oC. Coating treatment gave no effect unless combined with low temperature. Storage of 5oC without coating treatment was able to maintain fruit quality, particularly on its weight loss. The stearin could be used as cera alba substitution that it gave no negative effect.
Keyword: storage temperature, shelf life, dragon fruit, coating

Judul: Pengaruh Pelapisan Edibel Terhadap Umur Simpan dan Mutu Buah Naga Terolah Minimal yang Disimpan dalam Kemasan Atmosfer Termodifikasi
Abstrak: Minimally processed dragon fruit has a limited shelf life which can be extended if the fruits are subjected to edible coating and modified atmosphere packaging combined with low temperature storage. The objective of this study was to determine the influence of edible coating used for minimally processed dragon fruit on its quality and shelf life. Objective and organoleptic tests were conducted every two days observing the critical quality parameters of edible coated minimally processed fruits. The results indicated that selected glucomannan concentration for edible coating solution was 0.55%. The study recommended that edible coated minimally processed dragon fruits stored in a packaging made out of LDP no.4 as the bottom container with a ratio of 229 g fruits/180 cm2 areal, and stored at 5°C using stretch film for the modified atmosphere packaging. At the validated packaging design, edible coated minimally processed dragon fruits had four day shelf life with an organoleptic score of 3.5 in the range of 1-5.
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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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