Enhancing the ultrasound-assisted hot air drying of cherry through different pretreatments: Effect on drying characteristics, physicochemical quality, microstructure, texture and sensory evaluation

This study aims to optimize the drying performance and quality attributes of cherries through the application of diverse pretreatment techniques. Five pretreatment methods were employed prior to ultrasound-assisted hot air drying (USA-HAD): sodium carbonate and ethyl oleate (SC + EO), ethanol (CA), water blanching (WB), freezing (FZ), and sodium hydroxide (SH). The impact of these pretreatments on drying kinetics, physicochemical properties, microstructural characteristics, and sensory attributes of cherries was thoroughly assessed. The results demonstrated that all pretreatments significantly reduced drying time (16.67∼38.89 %), enhanced drying rates, and notably diminished energy consumption (21.25∼47.17 %). Cherries pretreated with SC + EO and subjected to USA-HAD exhibited markedly elevated (P < 0.05) concentrations of anthocyanins, total phenolic content (TPC), antioxidant activities (DPPH and ABTS), as well as individual sugars, malic acid, and quinic acid. Microstructural analysis revealed that SC + EO pretreatment effectively compromised the waxy cuticle of the cherry skin, promoting the formation of microporous channels, thereby accelerating moisture migration. Sensory evaluation and principal component analysis further corroborated the superior performance of SC + EO-pretreated cherries in terms of color, flavor, texture, and overall acceptability. In conclusion, SC + EO pretreatment proved to be a highly efficacious method in enhancing both drying efficiency and product quality, with substantial potential for industrial application.