In thailand,same treatment set of HCl dipping on 8th July 2013 was also stored for 67 days at 5. Result shown that there were some flesh discoloration showing a reddish color which could be due to anthocyanin pigment that renders further confirmation. Positive findings of cyanidin-3-glucoside equivalents in total anthicyanin including has been demonstrated by using pH differential method by spectrophometer (AOAC,2005b). Further analysis of the HCl treated longan should be conducted for identifying the anyhocyanin type. The pigment substance, cyanidin-3-glucoside, has been detected at low level 0.021 mg/kg in the flesh and not detected in pericarp of longan. It is hypothesized that this is caused by the acid in pericarp or during dip reacted with this substance in aril to become red color during storage. Such similar observation was detected in pericarp in litchi more than aril. This cyanidin-3-glucoside is one of the flavonoid in the phenolic group that is generally detected in other berries and it acts as an antioxidant which is safe for human consumption The anthocyanins identification using High Performance Liquid Chromatography (HPLP) should be investigated in the future.