TOTAL PHENOLIC, TOTAL FLAVONOID AND ROSMARINIC ACID CONTENTS IN ORTHOSIPHON STAMINEUS (MISAI KUCING) IN RELATION TO STORAGE CONDITIONS

Orthosiphon stamineus (Misai Kucing) is one of the important medicinal herbs in Malaysia. The effect of storage temperatures on total phenolics, total flavonoid and rosmarinic acid contents of O. stamineus in leaves were investigated. Fresh leaves of O. stamineus packed in perforated polyethylene bag then were stored at 5, 10°C and ambient (25°C) for 4 weeks. Results showed that total phenolic, total flavonoid and rosmarinic acid contents of fresh O. stamineus significantly reduced during storage at low temperature as well as at ambient. The losses of such phytochemicals were considerably much higher at ambient condition, at which total phenolics, total flavonoid and rosmarinic acid lost by 19.5, 24.9 and 27.5% from initial amount of 587.9 mg gallic acid equivalents (GAE)/100 g dry weight (DW), 697.8 catechin equivalents (CE)/100 g DW and 229.7 mg/100 g DW, respectively. Phytochemicals in O. stamineus seemed to be preserved well in storage at low temperature especially at 5°C, during first week of storage. The amount of total phenolic, total flavonoid and rosmarinic acid at one week of storage at low temperature (5 and 10°C) were ranged 623.4-640.4 mg GAE/100 g DW, 600.8-666.6 mg CE/100 g DW and 223.9-239.8 mg/100 g DW, respectively, which were almost identical to those after harvest. However, the losses of total phenolic, total flavonoid and rosmarinic acid in O. stamineus, were found increased with storage period, especially when stored at 10°C.