Effects of sunflower pectin on thermal stability of purple sweet potato anthocyanins at different pH

Yutong Liu; YingJia Tong; Qunyi Tong; Wentian Xu; Zeqing Wang

doi:10.1016/j.ijbiomac.2023.126663

Effects of sunflower pectin on thermal stability of purple sweet potato anthocyanins at different pH

Int J Biol Macromol. 2023 Dec 31;253(Pt 2):126663. doi: 10.1016/j.ijbiomac.2023.126663. Epub 2023 Sep 1.

Authors

Yutong Liu¹, YingJia Tong², Qunyi Tong³, Wentian Xu⁴, Zeqing Wang⁵

Affiliations

¹ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center, Jiangnan University, Wuxi 214122, Jiangsu, China.
² State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
³ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China. Electronic address: tqyjn@163.com.
⁴ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
⁵ School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center, Jiangnan University, Wuxi 214122, Jiangsu, China.

PMID: 37660844
DOI: 10.1016/j.ijbiomac.2023.126663

Abstract

The present study aimed to examine the impact of sunflower pectin (SFP) on the thermal stability and antioxidant activity of purple sweet potato anthocyanins (PSPA) at varying pH levels. It was observed that the pH value significantly influenced the ability of pectin to protect anthocyanins from thermal degradation, which was found to be associated with the rate of binding between PSPA and SFP. The binding rate of PSPA-SFP was observed to be highest at pH 4.0, primarily due to the influence of electrostatic interaction and hydrogen bonding. Monoacylated anthocyanins exhibited a binding rate approximately 2-4 % higher than that of diacylated anthocyanins. The PSPA-SFP demonstrated its highest thermal stability at pH 4.0, with a corresponding half-life of 14.80 h at 100 °C. Molecular dynamics simulations indicated that pectin had a greater affinity for the flavylium cation and hemiketal form of anthocyanins. The antioxidant activity of anthocyanins in PSPA and PSPA-SFP increased with increasing pH, suggesting that anthocyanins at high pH had higher antioxidant activity than anthocyanins at low pH.

Keywords: Anthocyanins; Antioxidant activity; Sunflower pectin; Thermal stability; pH.

MeSH terms

Anthocyanins / chemistry
Antioxidants / pharmacology
Asteraceae*
Helianthus*
Hydrogen-Ion Concentration
Ipomoea batatas* / chemistry
Pectins

Substances

Pectins
Antioxidants
Anthocyanins