Effects of Four Different Drying Methods on the Quality Characteristics of Peeled Litchis (<i>Litchi chinensis</i>Sonn.)
Chun Fang Song, Zhengwei Cui, Guang Yuan Jin, Arun S. Mujumdar, Jian Yu
Drying Technology
Abstract
Four different drying methods, namely, air drying (AD), microwave-assisted vacuum drying (MWVD), coupled microwave–hot air drying (MWAD), and freeze drying (FD), were studied, in terms of drying time, color, reducing sugar content, shrinkage, microstructure, and sensory evaluation. The drying rate of MWVD and MWAD were notably faster than that of AD and FD. The highest reducing sugar content was observed in MWAD, followed by MWVD. No significant differences were observed in reducing sugar between air-dried and freeze-dried products. FD had the best color and shrinkage among the other drying methods. The color and shrinkage of MWVD drying is close to the fresh litchis and much better than hot air and MWAD. Scanning electron microscopy (SEM) images showed that the MWVD and FD litchis have a porous structure, whereas AD and MWAD litchis have a compact structure. The sensory evaluation suggests that peeled litchis dried by the four studied drying methods are of a quality that is accepted by consumers.
Extracted Claims
11 claims extracted from this paper into the knowledge graph
freeze drying (FD) has best color and shrinkage among the drying methods
“FD had the best color and shrinkage among the other drying methods.”
AD and MWAD litchis have compact structure
“Scanning electron microscopy (SEM) images showed that the MWVD and FD litchis have a porous structure, whereas AD and MWAD litchis have a compact structure.”
coupled microwave–hot air drying (MWAD) has faster drying rate than air drying (AD) and freeze drying (FD)
“The drying rate of MWVD and MWAD were notably faster than that of AD and FD.”