Werner Mühlbauer

Drying characteristics of copra and quality of copra and coconut oil

Abstract The effects of drying air temperature up to 100°C and position of halved dehusked coconuts with respect to the direction of the air stream were investigated at constant air velocity of 0.5 m s−1 and tropical dew point temperature of 25°C so that good quality copra and coconut oil (CNO) were produced at the shortest drying time. The drying characteristics of copra as shown by the moisture reduction against the drying time, were significantly affected by the drying temperature, being fastest at highest temperature, but not by the position at which the halves were placed on the dryer. Drying time to reach the desired moisture content of 7% wet basis was significantly reduced when the temperature of the air-stream was increased from 40 to 90°C but not between 90 and 100°C. As the drying temperature was increased to 90°C, both copra and CNO quality were unaffected. Drying air temperature and position of the halves in relation to the sensory properties of copra showed that the highest temperature of 100°C caused excessive browning, but left the taste and smell unaffected. Neither drying temperature nor nut position affected significantly the various quality characteristics of CNO and this was also the case for fatty acid composition. The results suggest that drying temperature of 90°C is optimum for the production of high quality copra and CNO in the shortest drying time.

The Control of Postharvest Ripening Processes and its Implications for the Productivity of Mango Processing

The production of high-quality food depends not only on an appropriate processing technology but also on the selection of proper raw materials. This experience, well known among food manufacturers, can be exemplified in the case of mango processing.