Pengaruh Metode Pengeringan terhadap Mutu dan Sifat Fisiko-kimia Tepung Kasava Terfermentasi

Abstract

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.