Chemical fingerprint analysis of fermented Morinda citrifolia L. (Noni) juice by UHPLC Q-TOF/MS combined with chemometric analysis

Morinda citrifolia L. (Noni) has been widely used in traditional medicine in tropical zones and has become increasingly popular globally owing to its health benefits. Most noni fruits are consumed as juice, which is traditionally produced by the natural fermentation of noni fruits. In this study, the metabolic profiles of noni fruit juice (NJ1) and fermented noni fruit juices (NJ2 and NJ3) was compared. A total of 74, 83, and 91 compounds including anthraquinones, coumarins, flavonoids, phenolic acids, phenolics, terpenoids, and miscellaneous (acids, carbohydrates, vitamins, fatty acids, etc.) were tentatively identified from NJ1, NJ2, and NJ3 in both positive and negative electrospray ionization modes. The phenolic compound composition differed significantly between noni juice and fermented noni juice. The results of the unsupervised principal component analysis and hierarchical clustering analysis showed that the non-fermented juice group clustered with the fermented juice groups. Asperulosidic acid, isoasperulosidic acid, and rutin levels were higher in the NJ1 group than those in the NJ2 group. Deacetylasperulosidic acid and monotropein contents in NJ2 were higher than those in NJ1. Similarly, NJ1 had higher asperulosidic acid and isoasperulosidic acid than those in NJ3. The findings from this study have the potential to enhance the quality of fermented noni juice.