ศศิ ภวมัย. Effects of Surface Temperature and Rotational Speed of Roaster on Characteristics of Cassava Pearl. Master's Degree(Food Engineering). King Mongkut's University of Technology Thonburi. : King Mongkut's University of Technology Thonburi, 2006.
Effects of Surface Temperature and Rotational Speed of Roaster on Characteristics of Cassava Pearl
Abstract:
The objective of this work is to study the effects of surface temperature and rotational speed of roaster on the characteristics of cassava pearl. Roaster with a diameter of 0.34 m and length
of 0.3 m was constructed from stainless steel. The heating jacket was installed on the drum outer surface. The temperature and speed controller were set up. The effect of the rotational speed
on the mixing index of cassava pearl was investigated. Three rotational speeds (2.5, 3.5 and 7 rpm) with initially filling degrees of 2% and 4 % were used. The experimental results showed that
mixing index was higher than 0.95 within 80 seconds in all treatments. Then, the effects of the surface temperature (120, 140 and 160?C) and rotational speed of the roaster (2.5, 3.5 and 7 rpm)
on the characteristics of cassava pearl were investigated. The final percentage of moisture content of all samples was 6.21-18.76 percent while the degree of gelatinization was within the range
of 75.48 to 97.6 percent. The degree of gelatinization showed a linear relationship with the hardness of cassava pearl while the hardness of cooked cassava pearls was lower than the hardness of
cassava pearl before cooking. The lightness of cassava pearl decreased as the drum surface temperature increased. The drum surface temperature and rotational speed of roaster did not significantly
affect the a*-values. In contrast, b*-values increased as the drum surface temperature increased. The lightness of cooked cassava pearl was lower than the lightness of cassava pearl before cooking.