Khin Su Su Hlaing, Mouhamed Fall, Victor Christian Kaharso, Jiang Qixing, Wenshui Xia, Dawei Yu
This study investigated the effects of three extraction methods, ultrasound-assisted extraction (UAE), shaking-assisted extraction (SLE-1), and stirring-assisted extraction (SLE-2), on the physicochemical and structural characteristics, phenolic composition, and biological activities of Roselle leaf extract (RLE). Among the techniques, UAE outperformed the other methods, yielding extracts with enhanced physicochemical and biological properties. The results revealed that UAE-derived RLE exhibited significantly higher levels of total phenolics (747.34 mg gallic acid equivalents/g DW), total flavonoid contents 134.02 ± 1.48 (mg rutin/g), and condensed tannin contents (6.35 ± 0.10 mg catechin/g). Moreover, the RL extracted using the different methods showed antibacterial efficacy against Staphylococcus aureus and Escherichia coli. The UAE showed greater inhibitory effects on α-amylase (78.08%) and α-glucosidase (71.58%). Additionally, all RLE samples of main phenolic compounds in all RLE samples were identified using UPLC-Q-TOF-MS. These findings indicate that RLE could offer enhanced bioactivity, improved solubility, and potential applications as a functional ingredient in the food, pharmaceutical, and nutraceutical industries. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangsu, Wuxi, 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Jiangsu, Wuxi, 214122, China; Department of Food Technology, Widya Mandala Surabaya Catholic University, East Java, Surabaya, 60265, Indonesia; SoHao Fd-Tech Co., Ltd., Shandong, Qingdao, 266700, China