Pulsed vacuum drying (PVD) of wolfberry: Drying kinetics and quality attributes

Xie, Long, Zheng, Zhi-An, Mujumdar, A. S., Fang, Xiao-Ming, Wang, Jun, Zhang, Qian, Ma, Qin, Xiao, Hong-Wei, Liu, Yan-Hong and Gao, Zhen-Jiang (2018) Pulsed vacuum drying (PVD) of wolfberry: Drying kinetics and quality attributes. Drying Technology, . doi:10.1080/07373937.2017.1414055

Author Xie, Long
Zheng, Zhi-An
Mujumdar, A. S.
Fang, Xiao-Ming
Wang, Jun
Zhang, Qian
Ma, Qin
Xiao, Hong-Wei
Liu, Yan-Hong
Gao, Zhen-Jiang
Title Pulsed vacuum drying (PVD) of wolfberry: Drying kinetics and quality attributes
Journal name Drying Technology   Check publisher's open access policy
ISSN 1532-2300
Publication date 2018-01-22
Sub-type Article (original research)
DOI 10.1080/07373937.2017.1414055
Open Access Status Not yet assessed
Total pages 14
Place of publication New York, NY United States
Publisher Taylor and Francis
Language eng
Subject 1500 Chemical Engineering
1606 Physical and Theoretical Chemistry
Abstract The effects of drying temperature (50, 53, 56, 59, 62, and 65°C) and pulsed vacuum ratio defined as the vacuum pressure duration versus atmosphere pressure duration (3:3, 6:6, 9:2, 12:5, 15:1, 18:4 min/min) on pulsed vacuum drying (PVD) characteristics and quality attributes of wolfberry in terms of polysaccharide content, color parameters (L, a, b, ΔE, and C), rehydration ratio and microstructure were investigated. Results revealed that appropriate PVD can reduce drying time by 73.2% compared to hot air drying at the same drying temperature. The moisture effective diffusivity (D) ranged from 5.23 × 10 to 9.73 × 10 m/s, calculated using the Weibull distribution model. The polysaccharide content, L (lightness), a (redness/greenness) of the PVD products were higher than those of the hot air-dried samples at the same drying temperature. The total color difference (ΔE) and color intensity (C) of PVD samples were close to those of the fresh ones. The retention rate of total polysaccharide content of PVD samples was about 49–77%, which was significantly higher than 30% of the hot air-dried samples. The surface of PVD wolfberry was highly porous, which may enhance moisture transfer during drying as well as rehydration processes. The results of current work indicate that PVD is a promising technology for wolfberry process, for the reason that PVD can reduce drying time significantly as well as enhance the quality attributes in terms of the total polysaccharide content, color parameters and rehydration ratio.
Keyword Color parameters
polysaccharide content
pulsed vacuum drying
Weibull model
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Agriculture and Food Sciences
Version Filter Type
Citation counts: Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Thu, 29 Mar 2018, 21:21:46 EST