High-Throughput Analysis of Flavokawains in Kava (Piper methysticum Forst. f.) Roots, Chips and Powders and Correlations with Their Acetonic Extracts Absorbance Vincent Lebot 1 & Juliane Kaoh 2 & Laurent Legendre 3,4,5,6 Received: 17 November 2019 /Accepted: 18 May 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Kava is a non-alcoholic beverage prepared by cold water extraction of the ground roots and stumps of Piper methysticum Forst. f. Kava contains flavokawains (FKs) which have been suspected of being potentially cytotoxic. Current HPLC protocols are not adapted to high-throughput quantification before export. The objectives of the present study were (i) to analyse with HPTLC the individual FKs in roots, stump, stems and peelings of four varieties grown in a controlled environment; (ii) to quantify FKs in 1053 commercial samples exported from Vanuatu in 2017-18-19 (370 roots, 381 chips and 302 powders) and (iii) to assess the efficiency of a colorimetric test for routine control. HPTLC plate scanning at 355 nm offered good linearity for three FKs with R 2 > 0.99 and RSD < 3.0%. High total FKs (> 14 mg/g DW) were found in poor-quality varieties and in peelings unsuitable for consumption. Plant parts known for their good quality, such as roots and peeled stumps of noble varieties, presented low total FKs (< 7 mg/g). Great variation was observed in exported roots (2.53–24.56 mg/g), chips (2.73–18.03 mg/g) and powders (2.92– 16.41 mg/g). HPTLC proved reproducible for the high-throughput quantification of FKs in kava. A positive relationship was confirmed between the absorbance of the acetonic extract and the total FKs (R 2 = 0.5211) (n= 1053). Multivariate analyses revealed that in roots, chips and powders, the three FKs are significantly correlated with high absorbance values. The absorbance of the acetonic extract gives a fair assessment of the FK content in kava products. Keywords Chalcones . Cytoxicity . Flavokawains . Kavalactones . HPTLC . Plant partitioning Introduction Kava, the non-alcoholic traditional beverage of the Pacific, is prepared by cold water extraction of the ground fresh or dried roots and stumps of the plant species Piper methysticum Forst. f. The effect of kava can be refreshing when it is diluted and relaxant when it is more concentrated. Clinical trials examin- ing the efficacy of aqueous extracts of kava have not identified adverse health effects. The consumption of kava is considered safe and this beverage does not produce addiction or side effects when drank in moderation (FAO/WHO 2016). Dry kava is rich in starch (approx. 50% dry matter) and fibres (20%) with low minerals (3%), proteins (3%) and sugars (3%) and a residual humidity around 11%. For consumers, the most interesting compound is kavain, a kavalactone pro- ducing a fast relaxing effect (Chua et al. 2016). There are five other major kavalactones (KLs: methysticin, dihydromethysticin, dihydrokavain, yangonin and desmethoxy yangonin) and their composition and content are highly variable, depending on the age of the plant, the variety, the part of the plant and the environmental conditions (Wang et al. 2013). During the last decade, the international trade of kava has expanded rapidly and it is estimated that approximately 6000 tonnes of dried roots, chips and powders are traded annually and the market is still growing (PHAMA 2015). The major producing countries are located in the Pacific (Fiji, Samoa, Tonga and Vanuatu) but kava is increasingly imported in the USA where it is sold on the Internet and in urban kava bars (Martin et al. 2014). The Codex Alimentarius of the FAO/ * Vincent Lebot lebot@vanuatu.com.vu 1 CIRAD, UMR-AGAP, PO Box 946, Port Vila, Vanuatu 2 VARTC, PO Box 231, Luganville, Santo, Vanuatu 3 Université de Lyon, F-69622 Lyon, France 4 Université Lyon 1, Villeurbanne, France 5 CNRS, UMR 5557, Ecologie Microbienne, Villeurbanne, France 6 INRA, UMR 1418, Villeurbanne, France Food Analytical Methods https://doi.org/10.1007/s12161-020-01781-9