A simple HPLC-method for the quality assurance of Noni (Morinda citrifolia L.) juice

In 2003 pasteurized Noni (Morinda citrifolia) juice was approved as novel food by the EU commission. In the meantime the juice became very popular as a remedy against a broad variety of physical disorders. In order to investigate the quality of Noni juice products on the market, we developed an easy HPLC method based on an extraction of 1ml juice samples with ethyl acetate. Two pharmacologically active marker compounds, scopoletin and 2(E)-4(Z)-7(Z)-decatrienoic acid (CPX), were used for the characterization of the juices. It was shown that both compounds are present in fresh Noni fruits independent of the ripeness. The location of harvest was also of minor effect on the concentration, however an increase of the scopoletin content was observed after fermentation of the Noni juice. Considerable differences in the concentration of the marker compounds were observed after investigation of a variety of about 17 commercial Noni juices. The content of original Noni juice in these brands varied between almost 100% to less than 1%, even if these juices were labelled as „prepared from 100% pure Noni juice“. Our investigations demonstrate the importance of a quality control for Noni juices and provide an easy and quick analytical method for this purpose.