Kavalactone Content and Profile of Kava Cultivated on Taveuni, Qamea, and Rabi Islands of Fiji

The kava beverage of the Pacific is known for its intoxicating, soothing and relaxing effects, attributed to a group of compounds (called kavalactones) produced by the kava plant. An unfavorable kavalactone profile, however, contributes to side effects, including hepatotoxicity. Therefore, the chemical quality of kava is of key importance for consumer safety. This work investigated the chemical quality of the kava cultivated on the Taveuni, Qamea, and Rabi Islands by quantifying the main kavalactones in the roots and rhizomes of eighty-eight kava plants using the HPLC method. It was concluded that the farmers in these regions almost exclusively grow classified noble kava cultivars with a favorable kavalactone profile; the total kavalactone concentration varies between 7.2–14.1 wt.% and 4.7–8.2 wt.% in the dried roots and rhizomes, respectively. Kavain is the major kavalactone component (27–34 wt.% of the total amount of kavalactones), followed by methysticin, yangonin, or dihydrokavain in the roots, and dihydrokavain or methysticin in the rhizomes, respectively. One unclassified non-noble cultivar, with elevated levels of non-desirable dihydrokavain, dihydromethysticin, and flavokavains, is also identified and characterized.