Determination of Anthocyanins and Antioxidants in ‘Titanbicus’ Edible Flowers In Vitro and In Vivo

Titanbicus (TB), a hybrid of Hibiscus moscheutos × H. coccineus (Medic.) Walt., has potential to be used as an edible flower. In this study, proximate nutritional content, anthocyanin content, total polyphenol content (TPC), and antioxidant activities in vitro and in vivo were investigated. Three cultivars of TB, namely Artemis (AR), Rhea (R), and Adonis (AD), were used as materials. Protein and carbohydrates were the primary macronutrients, while crude fat and ash were detected in trace amounts. Cyanidin 3-glucoside (Cy3-G) and cyanidin 3-sambubioside (Cy3-Sam), were identified in all TBs. The highest anthocyanin content was observed in AD (47.09 ± 1.45 mg/g extract), followed by R and AR (6.04 ± 0.20 and 2.72 ± 0.11 mg/g extract, respectively). The TPC of AD (225.01 ± 1.97 mg/g extract) was greater than that of AR and R (185.41 ± 3.24 and 144.10 ± 1.71 mg/g extract, respectively). AD exhibited the strongest in vitro antioxidant activity in hydrophilic oxygen radical absorbance capacity, compared to the other two TBs. In addition, AD extract suppressed the generation of reactive oxygen species in caudal fin of wounded zebrafish. Antioxidant activities of AD appeared to be related to its total anthocyanin content, Cy3-G, Cy3-Sam, and TPC. Our findings indicate that TB, particularly the AD cultivar, would be an attractive source of bioactive compounds with antioxidant activities, and can improve both nutritional value and appearance of food.