Processing of Coconut Sap into Sugar Syrup using Rotary Evaporation, Microwave and Open-Heat Evaporation Techniques.

BACKGROUND: Coconut sugar has caramel colour with taste like brown sugar is commonly used as natural sweetener. However, coconut sugar was generally produced from coconut sap using a traditional method which is by heating the sap at high temperature (>100 degrees C) in an open pan for long hours (3-5 h). This conventional method had resulted in an over-cooked sugar, which leads to quality deterioration; both on physical and chemical properties of coconut sugar. This current study was aimed to investigate the processing of coconut sugar sap into syrup by using alternative processing methods such as rotary vacuum evaporation (RE) and microwave evaporation (ME) by comparing with open-heat evaporation (OHE) techniques. RESULTS: Coconut sugar syrup produced by Rotary evaporation at 60 degrees C and 250mbar vacuum (RE-60) had the least production time (12.2 min) and the lowest processing temperature (54.8 degrees C) as compared with ME (13 min and 103.2 degrees C) and OHE (46.8 min and 101.6 degrees C). It also had light brownish colour with higher L* value (35.17) as compared to ME (29.84) and OHE (23.84) methods. It was found to contain higher amounts of monosaccharides (fructose and glucose) and lower amounts of disaccharides (sucrose). Furthermore, the amount of energy required for RE-60 (0.35 kWh) was much less than OHE (0.83 kWh). CONCLUSION: This study provided an alternative processing method for sugar processing industry to produce coconut sugar using rotary evaporation method at 60 degrees C under 250 mbar vacuum with better physicochemical quality, shorter processing time and minimum input energy. This article is protected by copyright. All rights reserved.