The experiment started with selected pH of 3.3 based on literatures of Tang et al. (2011), Lucia et al. (2012) and a series of preliminary tests. At each pH level, including a lower and higher pH of 2.0 and 4.5, the optimum extraction time based on experiment result which gave the highest yield was determined. Each treatment was conducted in duplicates and completely randomized design (CRD) was used in this study.