A galacturonic acid-rich polysaccharide from Diospyros kaki peel: Isolation, characterization, rheological properties and antioxidant activities in vitro

Yanlong Cui; Ruiling Wang; Siyue Cao; Mohamedelfatieh Ismael; Xin Wang; Xin Lü

doi:10.1016/j.foodchem.2023.135781

A galacturonic acid-rich polysaccharide from Diospyros kaki peel: Isolation, characterization, rheological properties and antioxidant activities in vitro

Food Chem. 2023 Aug 1:416:135781. doi: 10.1016/j.foodchem.2023.135781. Epub 2023 Feb 24.

Authors

Yanlong Cui¹, Ruiling Wang¹, Siyue Cao², Mohamedelfatieh Ismael¹, Xin Wang¹, Xin Lü³

Affiliations

¹ Lab of Bioresources, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi Province 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi Province 712100, China.
² Lab of Bioresources, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi Province 712100, China.
³ Lab of Bioresources, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi Province 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi Province 712100, China. Electronic address: xinlu@nwsuaf.edu.cn.

PMID: 36871504
DOI: 10.1016/j.foodchem.2023.135781

Abstract

This research elucidated the structural characteristics and antioxidant activity of a galacturonic acid-rich polysaccharide (PPP-2) isolated from Diospyros kaki peel. PPP-2 was extracted by subcritical water and subsequently purified by DEAE-Sepharose FF column. PPP-2 (12.28 kDa) mainly contained galacturonic acid, arabinose, and galactose with the molar ratios of 87.15: 5.86: 4.31. The structural characteristics of PPP-2 were revealed through FT-IR, UV, XRD, AFM, SEM, Congo red, methylation, GC/MS assay and NMR spectrum. PPP-2 owned the triple helical structure and degradation temperature of 251.09 ℃. The backbone of PPP-2 was formed by →4)-α-d-GalpA-6-OMe-(1→ and →4)-α-d-GalpA-(1→ with the side chains of →5)-α-l-Araf-(1→, →3)-α-l-Araf-(1→, →3,6)-β-d-Galp-(1→ and α-l-Araf-(1→. Moreover, the inhibitory concentration (IC₅₀) of PPP-2 to ABTS•+, DPPH•, superoxide radical and hydroxyl radical were 1.96, 0.91, 3.63, and 4.08 mg/mL, respectively. Our results suggested that PPP-2 might be a novel candidate of natural antioxidant in pharmaceuticals or functional food.

Keywords: Acidic polysaccharide; Diospyros kaki peel; Rheological properties; Structural characterization.

MeSH terms

Antioxidants* / chemistry
Diospyros*
Hexuronic Acids
Polysaccharides / chemistry
Spectroscopy, Fourier Transform Infrared

Substances

Antioxidants
Polysaccharides
galacturonic acid
Hexuronic Acids