Abstract: This study examined the effects of five pretreatment methods namely ultrasound (US), one freeze-thaw cycle (FT-1), ultrasound combined with one freeze-thaw cycle (US + FT-1), two freeze-thaw cycles (FT-2), and ultrasound combined with two freeze-thaw cycles (US + FT-2) on the vacuum freeze drying (VFD) efficiency and quality attributes of Cantharellus cibarius. The results demonstrated that all pretreatments reduced the drying time (6.25%–37.50%) while increasing the total flavonoid (TFC) and total phenolic contents (TPC) and enhancing the antioxidant capacity. US + FT-1 reduced the drying time by 37.50% and resulted in the highest TFC ((2.79 ± 0.02) mg/g) and TPC ((7.94 ± 0.07) mg/g) and strong antioxidant activity. Additionally, this treatment reduced the bitter amino acid content while preserving high total amino acid levels. These findings indicate that all tested pretreatments improve the drying efficiency and quality of VFD-dried C. cibarius, with US + FT-1 being particularly effective for producing high-quality dried C. cibarius.

Key words: Cantharellus cibarius; ultrasound; freeze-thaw; vacuum freeze-drying efficiency; quality characteristics