Structural characteristics and gel properties of pectin from citrus physiological premature fruit drop

Tingting Qi; Jingnan Ren; Xiao Li; Qi An; Nawei Zhang; Xiao Jia; Siyi Pan; Gang Fan; Zhifeng Zhang; Kangning Wu

doi:10.1016/j.carbpol.2023.120682

Structural characteristics and gel properties of pectin from citrus physiological premature fruit drop

Carbohydr Polym. 2023 Jun 1:309:120682. doi: 10.1016/j.carbpol.2023.120682. Epub 2023 Feb 10.

Authors

Tingting Qi¹, Jingnan Ren¹, Xiao Li¹, Qi An¹, Nawei Zhang¹, Xiao Jia¹, Siyi Pan¹, Gang Fan², Zhifeng Zhang³, Kangning Wu³

Affiliations

¹ Key Laboratory of Environment Correlative Dietology, Ministry of Education; Hubei Province Key Laboratory of Fruit & Vegetable Processing & Quality Control, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
² Key Laboratory of Environment Correlative Dietology, Ministry of Education; Hubei Province Key Laboratory of Fruit & Vegetable Processing & Quality Control, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: fangang@mail.hzau.edu.cn.
³ Ningxia Huaxinda Health Technology Co., Ltd., Lingwu 751400, China.

PMID: 36906363
DOI: 10.1016/j.carbpol.2023.120682

Abstract

This study is the first to extract and characterize pectin from citrus physiological premature fruit drop. The extraction yield of pectin reached 4.4 % by acid hydrolysis method. The degree of methoxy-esterification (DM) of citrus physiological premature fruit drop pectin (CPDP) was 15.27 %, indicating it was low-methoxylated pectin (LMP). The monosaccharide composition and molar mass test results showed CPDP was a highly branched macromolecular polysaccharide (β: 0.02, Mw: 2.006 × 10⁵ g/mol) with rich rhamnogalacturonan I domain (50.40 %) and long arabinose and galactose side chain (32.02 %). Based on the fact that CPDP is LMP, Ca²⁺ was used to induce CPDP to form gels. Textural and rheological tests showed that the gel strength and storage modulus of CPDP were higher than commercial citrus pectin (CP) used in this paper due to the lower DM and rich neutral sugar side chains of CPDP. Scanning electron microscope (SEM) results showed CPDP had stable gel network structure.

Keywords: Citrus; Gel strength; Low-methoxylated pectin; Rhamnogalacturonan I; Rheology; SEM.

MeSH terms

Citrus* / chemistry
Fruit / chemistry
Gels / analysis
Pectins / chemistry

Substances

bis(cyclopentenecarboxylato)-1,2-diaminocyclohexane-platinum(II)
Pectins
Gels