Structure, spectral properties and antioxidant activity of melanoidins extracted from high temperature sterilized lotus rhizome juice

Xuefeng Ding; Yanbei Zhang; Jie Li; Shoulei Yan

doi:10.1016/j.ijbiomac.2024.132171

Structure, spectral properties and antioxidant activity of melanoidins extracted from high temperature sterilized lotus rhizome juice

Int J Biol Macromol. 2024 May 8;270(Pt 2):132171. doi: 10.1016/j.ijbiomac.2024.132171. Online ahead of print.

Authors

Xuefeng Ding¹, Yanbei Zhang¹, Jie Li², Shoulei Yan³

Affiliations

¹ College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
² College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Aquatic Vegetable Preservation and Processing Technology Engineering Centre of Hubei Province, Wuhan 430070, Hubei, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China. Electronic address: lijie1976@mail.hzau.edu.cn.
³ College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China; Aquatic Vegetable Preservation and Processing Technology Engineering Centre of Hubei Province, Wuhan 430070, Hubei, China; Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China.

PMID: 38729478
DOI: 10.1016/j.ijbiomac.2024.132171

Abstract

Melanoidins are complex macromolecular compounds closely associated with the browning phenomenon in high-temperature sterilized lotus rhizome juice (HTSL). This study aimed to preliminarily investigate the structural properties of melanoidins extracted from HTSL. Results showed that the average molecular weight of HTSL melanoidins ranged from 1.48 to 41.40 kDa. Medium and high molecular weight melanoidins were the main contributors to the brown color of HTSL. Sugars, proteins, and phenolics were present in HTSL, among which sugar was the most abundant, with glucose being the predominant monosaccharide in acid degradation products of melanoidins. Through fluorescence and ultraviolet spectral analysis, we found that the melanoidins contained carboxyl and carbonyl compounds, as well as furan and pyran heterocyclic compounds. The infrared spectra and nuclear magnetic resonance spectra revealed a prominent sugar absorption peak, indicating that sugar was the main component of the melanoidins of HTSL. Furthermore, in vitro antioxidant experiments showed that the antioxidant activity of melanoidins was significantly positively correlated with phenolic compounds. Our results indicated that there were differences in the structural properties of melanoidins fractions with different molecular weights. MW-H fraction significantly impacted the color and antioxidant activity of HTSL.

Keywords: Antioxidant activity; Composition; Lotus rhizome juice; Melanoidins; Molecular weight; Spectral characteristics.