Combined hot air-microwave drying of coconut grating for the production of virgin coconut oil

• Main Author: Neo, Hoon Hou
• Other Authors: Khong Poh Wah
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Chemical engineering::Food processing and manufacture
• Online Access: http://hdl.handle.net/10356/40033
• Institution: Nanyang Technological University

In this report, the author was trying to dry 100g of the coconut gratings with initial moisture content of 55% to 10 % moisture content using 3 drying methods; hot air, microwave and combined hot air-microwave drying methods. Hot air drying was carried out using air temperature of 50°C and 70°C at the air speed of 1m/s and 2m/s. Microwave drying uses 6 different microwave output powers 136W, 320W, 384W, 528W, 680W and 800W. The combined hot air and microwave drying methods was carried out at the air temperature of 50°C and 70°C at a constant air flow of 2m/s with 3 microwave output powers 320W, 680W and 800W. The drying time ranges from 130 to 320 minutes, 4.8 to 80 minutes and 4.5 to 17 minutes for hot air, microwave and combined hot air-microwave drying. The energy consumption was 3.15 to 7.03, 0.064 to 0.11 and 0.169 to 0.5 kWh respectively. The author had found out the optimum drying methods, drying duration and energy consumption to reduce the coconut grating moisture content. Combined hot air-microwave drying was the best method as it required 4.5 minutes to dry the coconut grating and it only consumed 0.169kWh.