Effects of Lycium barbarum Fruit Characteristics and Pretreatment on the Fruit Drying

【Objective】Drying is an important step of the processing of Chinese medicine wolfberry. The effects of different varieties (lines) of Lycium barbarum fruit traits and pretreatment on drying were studied to provide a valuable theoretical basis for the drying process of L. barbarum.【Method】In this study, different varieties (lines) of L. barbarum with obvious differences in dryness were used as experimental materials. The paraffin sectioning and scanning electron microscopy techniques were used to investigate the fruit processing characteristics, peel and cuticle structure, and peel waxy micromorphology, as well as effects of different pretreatment times on the drying of L. barbarum fruits, by which the influence of the L. barbarum fruit traits on the drying of the fruits was clarified.【Result】1) There were significant differences in the longitudinal diameter, fresh weight of 100 grains, and single fruit volume among different varieties (lines). L. barbarum ‘16-23-7-8’ had the largest transverse diameter, longitudinal diameter, fresh weight of 100 grains, and single fruit volume, while those parameters of L. barbarum ‘Ningqi No.1’ were the lowest. 2) With the development of the fruit, the thickness of the pericarp and cuticle increased gradually and there were significant differences in those traits among different varieties (lines). The pericarp thickness of L. barbarum ‘Ningqi No.5’ was the largest with 768.273 μm, and that of L. barbarum ‘Ningqi No.1’ was the lowest with 445.100 μm. L. barbarum ‘14-402’ had the thickest cuticle with 9.420 μm, and the L. barbarum ‘16-23-7-8’ cuticle was the lowest, being 7.528 μm. 3) The epidermis of L. barbarum fruit at mature stage was covered by fascicular waxy layer, and the waxy crystals were irregular flakes, and the flake waxy layer was thicker and arranged closely. 4) There were differences in the drying time of different varieties (lines) of L. barbarum fruits, and the order from easy to difficult was ‘Ningqi No.1’, ‘Z44’, ‘16-23-7-8’, ‘14-402’, and ‘Ningqi No 5’. Compared with the control, the average drying time was shortened by 4.10 h after alkali treatment, and the average drying time was shortened by 16.94 h after chloroform treatment.【Conclusion】The structure of L. barbarum peel affects the drying process of the wolfberry fruits by affecting the water transport pathway. Pretreatment can destroy the waxy layer of wolfberry epidermis and shorten the drying time. In this study, ‘Ningqi No.5’ is hard to dry, while ‘Ningqi No.1’ is the easiest to dry. Therefore, when drying wolfberry, the pretreatment method applied must take into account the differences in tissue and morphological anatomical characteristics among varieties. © 2024 Chinese Society of Forestry. All rights reserved.