Judul: Optimasi Suhu dan Waktu Penggorengan Hampa (Vacuum Frying) dalam Produksi Keripik Ubi Jalar Mentawai
Abstrak: In Mentawai, sweet potato are traded in fresh tuber. Postharvest processing is required to get value added of sweet potato one of them is vacuum frying. The aim of this research were to analyze effect of temperature and time of vacuum frying for characteristics of sweet potato chips, to determine the optimum temperature and time of vacuum frying and to determine production cost of sweet potato chips. The temperatures used in this research are 900C,1000C,1100C and frying times are 15,20,25 minutes. Quality parameters measured were yield, moisture content, colour, hardness, starch content, fat content, and organoleptic test performed. Vacuum frying temperatute and time significantly affect of the colours (L and b), starch content, and fat content. Based on the weighting test and analysis of variance so the best temperature and time of sweet potato chips is 1000C for 25 minute. Production cost of sweet potato chips for capacity 1 kg/process is Rp 110 875/kg and for capacity 8 kg/process is Rp 102 316/kg.
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Judul: Optimasi Proses Penggorengan Hampa (Vacuum Frying) Keripik Ikan Tongkol (Euthynnus Affinis).
Abstrak: Tongkol is a fish that belongs to the groups of high protein and low fat. Tongkol production in Mentawai Islands are very high, and the post-harvest handling has not done well, so it reduces the shelf life of fresh tongkol fish. The post-harvest handling of tongkol, such as vacuum frying are required to diversify tongkol fish, increase the shelf life, and to give more added value of tongkol fish. Vacuum frying has several advantages compared with frying in general, some of its benefits are vacuum frying does not change the color of the product, the product are more crispy, has a natural smell, and the most important is the products has a high shelf life. The aim of this research were to determine the effect of temperature and frying time to physico-chemical characteristic of fish chips, to determine the best temperature and frying time, and to determine the production cost of tongkol chips. Three oil temperatures for vacuum frying (80, 90, 100ºC) and three frying time (80, 90, 100 minutes) were considered. The temperature and time of frying significantly influenced yield, moisture content, fat content and protein content. The best fish chips were produced by vacuum frying at 100ºC for 90 minutes. The production cost of fish chips for every 100 grams is 14.000 Rupiahs.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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