PHYSICAL AND CHEMICAL CHARACTERISTICS OF OYSTER MUSHROOMS FLOUR (Pleurotus ostreatus) USING ROTARY VACUUM DRYER TYPE BATCH
Siti Djamila (a*), Amal Bahariawan (a), Iswahyono (a)
a) Departement of Agricultural Engineering
Politeknik Negeri Jember
jalan Mastrip 164
a*) umi.djamilasy[at]gmail.com
Abstract
Harvested oyster mushrooms with high moisture content are easily damaged by enzyme and microorganism. Drying the mushroom into flour using sun drying or artificial dryer can extend the storage time. Rotary vacuum dryer, an artificial dryer, works on vacuum conditions with automatic material reversal technology. The vacuum conditions can reduce boiling point and minimize the nutrition damage. The purpose of this study is to compare the physical and chemical characteristics of oyster mushroom flour produced by rotary vacuum dryer and sun drying. Rotary vacuum dryer works at 60 o C for 8 hours while sun drying requires 6 hours for 4 days. Next, 80 mesh hammer mill is used to grind the dried oyster mushroom. The process includes physical and chemical test analysis with the statistical results followed by t test to understand the two treatments average differences. The results show that all chemical characteristics: moisture content, protein, ash, dietary fiber, produced by rotary vacuum dryer is not significantly different from sun drying. The physical characteristic: color (lightness) and the water activity are not significantly different but the water holding capacity and bulk density are significantly different.
Keywords: oyster mushroom , rotary vaccum dryer , physical and chemical characteristics
Topic: Agriculture Engineering and Biotechnology