Liquid chromatography/mass spectrometry based fingerprinting analysis and mass profiling of Euterpe oleracea (acai) dietary supplement raw materials

Chemical fingerprinting and mass profiling methods to identify biologically active compounds in botanical dietary supplements is gaining much attention in recent years. Euterpe oleracea (acai) has been reported to be rich in health-beneficial chemical constituents. We have developed LC/MS based fingerprinting and mass profiling methods to identify fatty acids, anthocyanins and non-anthocyanin polyphenols in three processed raw materials; non-organic acai powder (ADSR-1), raw-organic acai powder (ADSR-2) and freeze-dried acai powder (ADSR-3) that are used in the preparation of botanical dietary supplements. For LC/MS analysis of fatty acids and non-anthocyanin polyphenols, the acai samples were extracted sequentially with dichloromethane followed by methanol. To study fingerprinting analysis of anthocyanins, acai samples were extracted with acidic methanol-water. The LC separation of fatty acids, non-anthocyanin polyphenols and anthocyanins in acai raw materials was achieved using a C18 column with a gradient mobile phase consisting of solvents A (0.1% formic acid in water), and B (0.1% formic acid in methanol). MS experiments were carried out with negative and positive mode electrospray ionization. LC/MS analysis of dichloromethane extracts of (ADSR-1), (ADSR-2) and (ADSR-3) acai powders have shown to contain fatty acids, gamma-linolenic acid, linoleic acid, palmitic acid, and oleic acid. Whereas, the fingerprinting analysis of methanol extracts of ADSR-1, ADSR-2 and ADSR-3 led to the identification of phenolic acids, anthocyanin and non-anthocyanin polyphenols. The results from our study may be useful for the authentication and quality assessment of acai dietary supplement raw materials. (C) 2012 Elsevier Ltd. All rights reserved.