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: Storage of minimally processed crystal guava coated by glucomannan in modified atmosphere packaging
Abstrak: There had been many studies on minimally processed fruits in Indonesia, but none had been conducted on crystal guava. Research had also been done for edible coated minimally processed mango (Wuryani et al., 1999), and snake fruits (Rusmono et al., 1998) using soybean protein isolate as the major ingredient for the edible coating. The objective of this research was to observe the respiration rates, the quality changes, and the shelf life of edible coated minimally processed crystal guava using glucomannan as the major ingredient for edible coating. Preliminary experiment resulted in the selection of 1% glucomannan for the edible coating selection due to the lowest respiration of the edible coated minimally processed crystal guava stored at 5 oC. Storage temperature at three levels 5 oC, 10 oC, and temperature room, and atmosphere composition at also three levels 16-18% O2 and 3-5% CO2, 14-16% O2 and 3-5% CO2, 16-18% O2 and 5-7% CO2 were applied to the edible coated minimally processed crystal guava. The results indicated that storage temperature of 10 oC, and atmosphere composition of 14-16% O2 and 3-5% CO2 were favored compared to the room condition. The packaging films appropriate for the selected condition were stretch film and polypropylene film. Validation experiment used a packaging made of LDPE no.4 for the bottom container accommodating 166-277 g edible coated minimally processed crystal guava which were then covered by stretch film and polypropylene film. It was concluded that edible coated minimally processed crystal guava was best to be stored at 10 oC in a modified atmosphere packaging using stretch film with the ratio of weight to area 200 g/ 240 cm2 since it would be still accepted on the sixth day storage with an organoleptic score of 3.5 in the range of 1-5.
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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