Ultrasound-assisted extraction of natural antioxidants from the flower of Limonium sinuatum: Optimization and comparison with conventional methods

• Published in: Food chemistry 2017-02, Vol.217, p.552-559
• Main Authors: Xu, Dong-Ping, Zheng, Jie, Zhou, Yue, Li, Ya, Li, Sha, Li, Hua-Bin
• Format: Article
• Language: English
• Subjects: Antioxidant; Antioxidants - analysis; Ethanol - chemistry; Flower; Flowers - chemistry; Limonium sinuatum; Plant Extracts - analysis; Plumbaginaceae - chemistry; Polyphenols - analysis; Reproducibility of Results; Solvents; Ultrasonics; Ultrasound-assisted extraction
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.09.013

•Ultrasound-assisted extraction of natural antioxidants from the flowers of Limonium sinuatum.•Ethanol concentration, solvent/material ratio, ultrasound irradiation time and temperature were investigated.•Response surface methodology used to optimize parameters and study combined effects.•Experimental values obtained were compared against conventional maceration and Soxhlet extraction methods.•The UAE method is more efficient for antioxidant extraction. Natural antioxidants are widely used as dietary supplements or food additives. An optimized method of ultrasound-assisted extraction (UAE) was proposed for the effective extraction of antioxidants from the flowers of Limonium sinuatum and evaluated by response surface methodology. In this study, ethanol concentration, ratio of solvent to solid, ultrasonication time and temperature were investigated and optimized using a central composite rotatable design. The optimum extraction conditions were as follows: ethanol concentration, 60%; ratio of solvent to solid, 56.9:1mL/g; ultrasonication time, 9.8min; and temperature, 40°C. Under the optimal UAE conditions, the experimental values (483.01±15.39μmolTrolox/gDW) matched with those predicted (494.13μmolTrolox/gDW) within a 95% confidence level. In addition, the antioxidant activities of UAE were compared with those of conventional maceration and Soxhlet extraction methods, and the ultrasound-assisted extraction could give higher yield of antioxidants and markedly reduce the extraction time.