3.3. Active principle contents
The active principle contents were determined in terms of the total phenolic content. The TPC of the sticky rice husks (RD6) extracted for 60 and 120 min were higher than Khao Dawk Mali (KDML) 105 rice grown in northeastern Thailand, which had the highest content of GAE (220 ± 0.3 mg GAE/g extract) (Butsat and Siriamornpun, 2010). In addition, the TFC was determined due to the importance in cosmetics for wrinkle treatment (Churienthong et al., 2010). The active principle contents were consistent with antioxidant activity and extract yield. The longest time of extraction resulted in the highest active principle content (Table 1). Furthermore, refluxing for 120 min significantly extracted more active contents than those of shorter times (p < 0.05)