Effect of initial moisture content on physical properties of Orthosiphon stamineus ground powder during storage

Abstract

Initial moisture content of ground powder is very important factor in maintaining the physical quality of the product during storage. This research was conducted to investigate the effect of initial moisture content of Orthosiphon stamineus ground powder on physical properties such as moisture content, water activity and colour properties during short term storage period. In this research, the experimental treatments were arranged in a completed randomized design (CRD) that consisted of two main factors which were initial moisture content (8, 13 and 20 %) and storage period (0, 2, 4, 6, 8 and 10 weeks). The changes of moisture content, water activity and colour properties were analyzed using moisture analyzer, water activity meter and chroma meter, respectively. From the results, it was revealed that the best initial moisture content to maintain the quality of O. stamineus ground powder was 13 %. At early of storage period, moisture content and water activity were slightly reduced and they started to stable at week 8 to 10. The consistency of moisture content and water activity is expected to last for the next 6 months under same storage condition. However, it could be observed that the colour of O. staminus ground powder was slightly affected during short term storage.