Effects of ripening stage on physicochemical properties, drying kinetics, pectin polysaccharides contents and nanostructure of apricots

Li-Zhen Deng; Zhongli Pan; Qian Zhang; Zi-Liang Liu; Yang Zhang; Jian-Sheng Meng; Zhen-Jiang Gao; Hong-Wei Xiao

doi:10.1016/j.carbpol.2019.114980

Effects of ripening stage on physicochemical properties, drying kinetics, pectin polysaccharides contents and nanostructure of apricots

Carbohydr Polym. 2019 Oct 15:222:114980. doi: 10.1016/j.carbpol.2019.114980. Epub 2019 Jun 7.

Authors

Li-Zhen Deng¹, Zhongli Pan², Qian Zhang³, Zi-Liang Liu¹, Yang Zhang¹, Jian-Sheng Meng⁴, Zhen-Jiang Gao¹, Hong-Wei Xiao⁵

Affiliations

¹ College of Engineering, China Agricultural University, P.O. Box 194, 17 Qinghua Donglu, Beijing, 100083, China; Engineering Research Center for Modern Agricultural Equipment & Facilities, Ministry of Education, Beijing 100083, China.
² Department of Biological and Agricultural Engineering, University of California, One Shields Avenue, Davis, CA 95616, USA.
³ College of Mechanical and Electrical Engineering, Shihezi University, Shihezi 832001, China.
⁴ College of Engineering, China Agricultural University, P.O. Box 194, 17 Qinghua Donglu, Beijing, 100083, China; ShangQiu Food and Drug Administration, ShangQiu, Henan Province 476000, China.
⁵ College of Engineering, China Agricultural University, P.O. Box 194, 17 Qinghua Donglu, Beijing, 100083, China; Engineering Research Center for Modern Agricultural Equipment & Facilities, Ministry of Education, Beijing 100083, China. Electronic address: [email protected].

PMID: 31320051
DOI: 10.1016/j.carbpol.2019.114980

Abstract

Effects of ripeness (four stages from the lowest to highest degree-I, II, III, and IV) on the physicochemical properties, pectin contents and nanostructure, and drying kinetics of apricots were investigated. The color values (L^*, a^*, and b^*) and total soluble solid content increased during ripening, while the titratable acidity content and hardness decreased. The water-soluble pectin content increased as ripening progressed, but the chelate- and sodium carbonate-soluble pectin contents gradually declined. Atomic force microscopy imaging indicated that the pectin depolymerization occurred during ripening. Fruits at stage III obtained the highest drying rate, and the drying time was reduced by 27.27%, 17.24%, and 7.69% compared to those of stage I, II and IV, respectively. Results showed that the ripeness had significant influence on the drying kinetics, which is related to the modification of physicochemical and pectic properties. The ripeness classification is an essential operation for achieving effective drying process.

Keywords: Atomic force microscopy; Citric acid (PubChem CID: 311); Distilled water (PubChem CID: 962); Drying; Ethanol (PubChem CID: 702); Galacturonic acid (PubChem CID: 439215); Glucose (PubChem CID: 5793); Nanostructure; Pectin (PubChem CID: 441476); Pectin fraction; Potassium acetate (PubChem CID: 517044); Ripening stage; Sodium carbonate (PubChem CID: 10340); Sodium hydroxide (PubChem CID: 14798); Texture; m-Hydroxybiphenyl (PubChem CID: 11381).