Multi-dimensional Analysis of the Effect and Mechanism of Blanching Pretreatments on the Texture Formation of Dried Apricot Fruits

In this study, the effects and mechanisms of hot water blanching and steam blanching pretreatments on the texture formation of dried apricot fruits were compared and analyzed from the aspects of macroscopic texture, water distribution, microstructure and cell wall component characteristics. The results showed that the strong thermal penetration effect of steam blanching significantly weakened intercellular adhesion, reduced the hardness of dried fruits and enhanced the ductility. The hardness of the dried fruit prepared by steam pretreatment at 95 ℃ was 502.64 g, and its ductility was significantly higher than that of other groups. Hot water blanching pretreatment remarkably facilitated the the dissolution of sugar molecules, resulting an increase in the hardness of dried fruits, with the highest value (1067.42 g) observed at 95 ℃. Furthermore, steam pretreatment at 75 ℃ significantly reduced the mobility of water molecules, which was accompanied by an increase in the proportion of immobilized water (S₂₂ increased to 97.33%). The surface of the dried fruit with steam pretreatment at 75 ℃ was flat, with enhanced reflectivity and reduced absorbance, which was consistent with improved color. Moreover, steam blanching affected the thermal stability of the cell wall by promoting the exposure of carboxylic acid groups and the cleavage of glycosidic bonds, thereby affecting the texture formation of dried apricot.