Effects of Different Natural Drying Methods on Drying Characteristics and Quality of Diaogan apricots

Abstract

Drying is one of the best methods to preserve the quality of fresh fruits and prolong their shelf life. This study focuses on Prunus armeniaca L. cv. ‘Diaogan’ (commonly known as Diaogan apricot) sourced from Xinjiang, China to explore the impact of two natural drying methods (shade drying and open-air drying in the rocky desert) on the drying kinetics, color, textural characteristics, microstructure, chemical properties, and antioxidant capacity of Diaogan apricots. The experimental results indicate that throughout the natural drying process, the time required for open-air drying in the rocky desert was reduced by 26.47% compared to shade drying. The L*, a*, and b* values of the shade- and ventilation-dried Diaogan apricots were higher than those sun-dried in the rocky desert, exhibiting a lower color difference (ΔE) than apricots dried through rocky desert sun drying. Specifically, the ΔE for shade-dried Diaogan apricots was 19.66 ± 0.24. The Diaogan apricots dried in the rocky desert exhibited greater hardness, lower elasticity, stronger adhesiveness, and higher chewiness compared to those dried in the shade, with the hardness, adhesiveness, and chewiness being, respectively, 14.71%, 18.89%, and 35.79% higher. Scanning electron microscopy (SEM) observations revealed that the high temperatures experienced during open-air drying in the rocky desert caused rapid dehydration of the Diaogan apricot’s skin, leading to clogging and crust formation in the flesh pores, along with deformation or tearing of the tissue structure, ultimately resulting in poor rehydration ability. After drying, there was a significant increase in the soluble solids in the Diaogan apricots, whereas titratable acidity, total phenols, ascorbic acid, and antioxidant capacity were significantly decreased (p < 0.05). In summary, the quality of dried Diaogan apricots post-drying is dependent on the natural drying method employed, with shade drying resulting in superior quality of Diaogan apricots compared to open-air drying in the rocky desert. This study offers fundamental data and serves as a theoretical reference for the industrialized production of apricots.