Effects of air-impingement jet drying on drying kinetics, color, polyphenol compounds, and antioxidant activities of Boletus aereus slices.

The aim of the study is to interpret the effects of air-impingement jet drying (AIJD) on drying kinetics, color, polyphenols, and antioxidation ability of Boletus aereus slices. Page model was most suitable for expressing and predicting AIJD curves of B. aereus slices. The moisture-effective diffusion coefficient of AIJD ranged from 7.8876 × 10-10 to 2.1426 × 10-9 m2 /s, and AIJD also showed high efficiency due to its low activation energy (45.37 kJ/mol). AIJD is better for B. aereus slices than hot air drying (HAD) in accelerating the drying rate (DR) and shortening drying time, and maintaining color. p-hydroxybenzoic acid, protocatechuic acid, and rutin were identified in B. aereus slices by ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS). Total polyphenols, flavanone, phenolic acids, and antioxidant activities were significantly lower in dried B. aereus slices than those in fresh B. aereus slices. In AIJD, drying temperature had the greatest effect on the quality of B. aereus slices, and AIJD at 50 °C is the optimum drying condition for B. aereus slices. PRACTICAL APPLICATION: Boletus aereus occurs in many countries all over the world. In this paper, the effect of AIJD on color, polyphenols, and antioxidation ability in B. aereus slices and its drying kinetics were studied. AIJD is an efficient drying method for B. aereus by decreasing its drying time, increasing DR, and protecting the color of B. aereus. These findings have provided important reference basis for people to have a better understanding of AIJD method, which was used to dry B. aereus. This study also provides a new technique for drying B. aereus, which could improve dry efficiency and reduce drying cost.