Judul: Shelf life and quality of sapota cultivar sukatali st1 coated by wax
Abstrak: Waxing is one way that can be used to extend the shelf life of horticultural products with a relatively low cost. By doing waxing on sapota, it was expected to increase the shelf life of the fruit, so in marketing, sapota quality could be improved. The material used to coat the sapota was beeswax, Sapota cultivar Sukatali ST1 was obtained from the farmers at Sumedang, Jawa Barat. Several concentrations of wax were applied in the preliminary experiment, i.e, 0%, 2%, 4%, 6%, 8%, 10%, and 12% at room temperature. The results indicated that sapota coated with a wax concentration of 10% had longer shelf life of 5 days. In the next stage, the wax applied in the treatments were 9%, 10% , 11%, and without wax coating as control. In addition to room temperature, 15°C storage temperature was also applied as treatment. Observations were made on the respiration rate, weight losses, total soluble solids, hardness, and organoleptic for every 2 days. The results of this experiment saw that sapota coated with a wax concentration of 10% and 11% at room temperature achieved the longest shelf life for 5 days. At 15 ° C storage temperature, longer shelf life of sapota was performed by sapota coated with 9% wax with a shelf life of 11 days.
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Judul: Shelf life and quality of edible coated fresh cut sapota (Achras zapota, L) cultivar sukatali ST1 stored in modified atmosphere packaging
Abstrak: Minimally processed fruit is one of the options that provide practical and ready to eat food for the urban people that has instant life style. Edible coating and low temperature are required to keep the quality and the shelf life of the minimally processed fruits. The objective of this study was to determine the influence of edible coating used for fresh cut sapota cultivar Sukatali ST1 on its quality and shelf life. Preliminary experiment resulted in the selection of 0.5% glucomannan out of 0.5%, 0.55%, and 0.6% concentration for the edible coated fresh cut sapota due to its lowest respiration. Two treatments, storage temperature at three levels 5oC, 10oC, 15oC and atmosphere composition at also three levels 16-18% O2 & 2-4% CO2, 14-16% O2 & 2-4% CO2, and 14-16% O2 & 4-6% CO2 were applied to the edible coated fresh cut sapota cultivar Sukatali ST1. The results indicated that storage temperature of 10 oC, and atmosphere composition of 14-16% O2 and 2-4% CO2 were favored compared to the room condition. The packaging films appropriate for the selected condition were stretch film and polypropylene film. The validation experiment concluded that edible coated fresh cut sapota cultivar Sukatali ST1 was best to be stored at 10 oC in a modified atmosphere packaging using stretch film, which was still accepted by consumers on the sixth day storage with an organoleptic score of 3-5 in the range of
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Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix