Judul: Quality of instant edible canna (Canna edulis Kerr.) powder and its porridge processed by drum dryer
Abstrak: Edible canna (Canna edulis Kerr.) is one of local tubers that has high content of starch so it can be used for food diversification. Processing technology that has been applied so far is to make transparent starch noodle (Roisah, 2009) and canna starch (Ciptadi et al. 1980). Edible canna has a lot of fiber so it can be easily digested. The aim of this research is to explore the process characteristics and quality of drum dried instant canna powder that would be rehydrated into edible canna porridge. Dried edible canna had been succesfully made from edible canna slurry developed from cooked mashed red edible canna corm from farmers in Bogor district and then dried using double drum dryer. Preliminary research was applied to determine the best cooking time and RPM of the double drum dryer. Fifty minutes and three RPM were determined as the best in instant canna powder brightness so it were used in the following research phases. Two treatments were applied, 1)feed slurry composition at three levels, 1:2, 1:3, and 1:4 (ratio cooked mash edible canna to water) and 2)steam pressure at also three levels, 300 kPa, 400 kPa, and 500 kPa. The results indicated that dried canna powder produced at 500 kPa steam pressure combined with 1:4 feed slurry composition had the best moisture content that was 5.07% and it had the best brightness, 83.25. The organoleptic test, however, suggested that taste, aroma, and color of edible canna porridge rehydrated from dried instant edible canna powder was favoured for the combination treatment of steam pressure 500 kPa and 1:2 feed slurry concentration. Treatment of steam pressure 500 kPa and 1:3 feed slurry concentration had the highest viscosity that was 10 200 cp. The treatment of steam pressure and feed slurry composition had significant effect on moisture content, percentage of one hundreds mesh particle of instan canna powder, and the organoleptic test. While viscosity and brightness were not affected significantly.
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Judul: Produksi Pati Ganyong (Canna edulis Kerr) Resisten Tipe IV melalui Modifikasi Asetilasi
Abstrak: Edible canna is a potential forest product that can be used as food diversification. The objective of this research was to obtain resistant starch which has been proven for its physiological effect. The production of resistant starch was done by chemically modified which used different concentration of acetic anhydride, namely 3, 4, and 5% in 300 g of edible canna. Two types of edible canna used in this research are red edible canna and white edible canna. The degree of substitution which gained through acetylation is 0.082, 0.168, 0.257 for red edible canna and 0.082, 0.168, 0.257 for white edible canna. Through proximate analysis, modification of edible canna starch resulted in increase of water content and decrease of ash content, while protein content, lipid and carbohydrate content showed no relatively difference. Total starch content, amylose, amylopectin, dietary fiber, resistant starch and digestibility of starch were measured for edible canna and the selected modified edible canna (4%). The results showed that modification through acetylation can increase resistant starch content. It increased 3.54% in red edible canna while for white edible canna is 3.80%. These results influenced the increasing of total dietary fiber with value 2.45% for red edible canna and 1.95% for white edible canna. The increasing of dietary fiber will result in the decreasing of digestibility of starch with value 1.58% for red edible canna and 1.98% for white edible canna.
Keyword: starch modification, resistant starch type IV, digestibility, Canna edulis

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