Improving the color stability and antioxidation activity of blueberry anthocyanins by enzymatic acylation with p-coumaric acid and caffeic acid

• Published in: Food science & technology 2020-08, Vol.130, p.109673, Article 109673
• Main Authors: Liu, Jingna, Zhuang, Yuanhong, Hu, Yonghua, Xue, Shan, Li, Hui, Chen, Lian, Fei, Peng
• Format: Article
• Language: English
• Subjects: Anthocyanin; Antioxidation activity; Colour stability; Enzymatic acylation
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2020.109673

In this work, p-coumaric acid and caffeic acid were grafted on blueberry anthocyanins through enzyme catalysis method to improve their colour stability and antioxidant activity. The acylation degrees of p-coumaric acylated anthocyanins (Co-An) and caffeic acid anthocyanins (Ca-An) reached 5.38% and 5.68%, respectively. The results from Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy and hydrogen nuclear magnetic resonance implied that p-coumaric acid and caffeic acid grafted on the 6-OH of glucoside and galactoside and the 5-OH of arabinose through esterification reaction. As revealed in the in vitro experiment on antioxidation activity and the experiment on colour stability, Co-An and Ca-An showed stronger antioxidant activity in DPPH assay and β-carotene bleaching assay and higher colour stability during storage at 25 °C, 40 °C and 60 °C than native blueberry anthocyanins. [Display omitted] •p-Coumaric acid and caffeic acid were grafted on blueberry anthocyanins through enzymatic method.•The color stability and antioxidation activity of blueberry anthocyanins were definitely improved.•The graft sites were on the 6-OH of glucoside and galactoside and the 5-OH of arabinose.