Evaluation of single bed and multi bed dried copra on the quality of extracted coconut oil

Abstract

Single bed and multi bed drying of copra was evaluated using a hybrid dryer with three compartments. A high percentage (> 75%) of white copra resulted in single bed drying at low temperatures (< 60 °C), while a comparatively lower percentage (< 22%) of white copra resulted from multi bed drying. The percentages of white and light brown copra in the bottom, middle and top beds of the multi bed dryer were 85.0%, 93.8% and 91.3%, respectively. A high production rate per unit cross sectional area of 2.06 kg/h could be achieved with multi bed drying as compared to single bed drying (0.90 kg/h at 55 °C and 0.97 kg/h at 60 °C). The specific moisture extraction in multi bed drying was 0.112 kg/kWh as compared to 0.064 kg/kWh at 55 °C and 0.065 kg/kWh at 60 °C in single bed drying. The oil extracted from both white and light brown copra was comparable with the Sri Lanka Standards for virgin coconut oil except the notably higher content of free fatty acids (FFA).