Acidic electrolyzed water treatment retards softening and retains cell wall polysaccharides in pulp of postharvest fresh longans and its possible mechanism

Junzheng Sun; Hongbin Chen; Huilin Xie; Meiling Li; Yihui Chen; Yen-Con Hung; Hetong Lin

doi:10.1016/j.fochx.2022.100265

Acidic electrolyzed water treatment retards softening and retains cell wall polysaccharides in pulp of postharvest fresh longans and its possible mechanism

Food Chem X. 2022 Feb 23:13:100265. doi: 10.1016/j.fochx.2022.100265. eCollection 2022 Mar 30.

Authors

Junzheng Sun^{1

2}, Hongbin Chen^{1

3}, Huilin Xie^{1

2}, Meiling Li^{1

2}, Yihui Chen^{1

2}, Yen-Con Hung⁴, Hetong Lin^{1

2}

Affiliations

¹ Institute of Postharvest Technology of Agricultural Products, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
² Key Laboratory of Postharvest Biology of Subtropical Special Agricultural Products, Fujian Province University, Fuzhou, Fujian 350002, China.
³ College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou, Fujian 362000, China.
⁴ Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223, United States.

Abstract

Effects of acidic electrolyzed water (AEW) treatment (pH = 2.5, ACC = 80 mg L^-1, 10 min) on pulp firmness, amounts of CWM and CWP, activities and expression of relevant genes of CWDEs in pulp of Fuyan longan during storage at 25 °C were evaluated. Compared to control samples, during storage, AEW-treated fruit retained a higher pulp firmness, prevented WSP formation, reduced the degradation of CSP, cellulose and hemicellulose, and lowered CWDEs activities and their corresponding gene expression. When stored for 5 d, pulp firmness (113.6 g mm^-1), CWM (13.9 g kg^-1), and CSP (1.4 g kg^-1) in AEW-treated fruit displayed the clearly higher contents than those in control samples. These data suggest that AEW treatment can slow down the pulp softening and retain higher pulp CWP levels in postharvest fresh longans, which was because AEW lowered activities of CWDEs and its gene expression levels, and maintained the cell wall structure's integrity.

Keywords: 1-MCP, 1-methylcyclopropene; AEW, acidic electrolyzed water; Acidic electrolyzed water; CEL, cellulase; CSP, covalent-soluble pectin; CWDEs, cell wall degrading enzymes; CWM, cell wall materials; CWP, cell wall polysaccharides; Cell wall degrading enzymes; Cell wall polysaccharides; Gene expression; ISP, ionic-soluble pectin; Longan fruit; NFT, near freezing temperature; PE, pectinesterase; PG, polygalacturonase; Pulp firmness; WSP, water-soluble pectin; XET, xyloglucan endotransglycosylase; β-Gal, β-galactosidase.