Judul: Pengaruh Perlakuan Panas sebelum Penggorengan terhadap Kerenyahan
Abstrak: Cassava is one of the local commodities of Indonesia that can be found easily at many places. Cassava chip is one of the popular snacks in Indonesia and crispness becomes one of the important factors to measure cassava chips quality. Some efforts have been tried to enhance the crispness of cassava chip. Heating processes before frying, such as steaming and boiling, are explored whether they can help to enhance cassava chip crispness or not. Steaming and boiling can cause the cassava starch gelatinization. As a result, the starch granule swells because of water hydration. When cassava slices is fried, the water comes out and small pores formed. The pores can cause the crispness of chips. The crispness was analyzed by sensory evaluation using rating and triangle test as subjective test and physical test using texture analyzer as objective test. Proximate analysis was also done to see if there are any effects of nutrients change because of heating processes to crispness. The result showed that steaming and boiling cassava slices before frying enhanced the crispness of cassava chips. Nutrients changed because of these heating processes.
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Judul: Pengaruh Metode Pengeringan terhadap Mutu dan Sifat Fisiko-kimia Tepung Kasava Terfermentasi
Abstrak: Cassava is one important food crops in Indonesia. Carbohydrate is major components in cassava tubers, and made it suitable used for food and energy sources. Nowadays cassava is mainly utilized as direct food, cassava flour and cassava starch (tapioca). But high moisture and prussic acid (HCN) contents in cassava tuber made limitation for human consumption. Fermentation and drying of cassava plays important roles in cassava flour production, since they can influence to the flour characteristics. This research investigated the effect of drying methods of fermented cassava slurry to the flour’s chemical composition and its physico-chemical properties. Fermentation of cassava tuber was conducted using standard operation procedure for MOCAF (modified cassava flour) prepared by Dr. Achmad Subagio (Jember University). There were three drying methods used in research; direct sundrying (16 hours), green house effect drying (hours), and oven drying (12 hours). It is also investigated the duration of drying process; especially for sundrying and green house effect drying, as 3, 5, and 7 hours and then furthered with oven drying for 9, 7 and 5 hours. Solar energy, especially ultra violet irradiation has been proven improved the flour quality. Drying on the green house effect chamber (40,1oC) provided higher average drying temperature compared to direct sundrying (33,5oC), but lower than oven drying (52,6oC). Differences in drying methods gave significant effects on moisture, ash, crude fiber, fat, protein, starch and HCN contents; whiteness degree of flours, total of microbes, microscopic appearance of starch granules, water and oil absorptions, solubility and swelling power at 90oC, and visco-amylography characteristics. All drying methods significantly reduced the HCN contents of flours, but direct sundrying and green house effect drying accelerate the liberation of starch, and caused high final viscosity of flours. Full green house effect drying (16 hours) was recommended for fermented cassava flour since it produced the flour with higher maximum and final viscosity compared to others.
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Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik