RESUMO
INTRODUCTION: The hibiscus flower has received increasing interest because it contains high levels of bioactive compounds with remarkable functional properties. To the best of our knowledge, for the first time a detailed description of the carotenoid composition of hibiscus calyces is reported. OBJECTIVES: Identification and quantification of carotenoids, phenolic compounds and antioxidant activity from hibiscus calyces. MATERIAL AND METHODS: The composition of the carotenoids and phenolic compounds from hibiscus calyces was determined by high-performance liquid chromatography coupled to a diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS). Antioxidant activity was assessed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and hydroxyl radicals scavenging assays. RESULTS: Twenty-one carotenoids were found and from these compounds 15 were identified or tentatively identified. The major carotenoids were all-trans-lutein (316.43 ± 19.92 µg/100 g) and all-trans-ß-carotene (147.76 ± 5.59 µg/100 g). Twenty phenolic compounds were found, from which 14 compounds were identified or tentatively identified. The major phenolic compounds were delphinidin 3-sambubioside (218.17 ± 12.69 mg/100 g) and 3-caffeoylquinic acid (79.22 ± 7.01 mg/100 g), representing almost 60% (w/w) of the total phenolic compounds from hibiscus calyces. The hibiscus presented low vitamin A activity, measure as retinol activity equivalent (13.52 µg/100 g). The scavenging activity of ABTS and hydroxyl radicals were 7.8 µmol Trolox equivalent/g and 81%, respectively. CONCLUSION: In this study we have shown that the hibiscus calyces can be considered as a food rich in lutein, chlorogenic acids and anthocyanins (delphinidin 3-sambubioside).
