Abstract
•Five drying techniques were used for drying garlic slices.•Different drying techniques significantly affected the quality of garlic.•Freeze dried garlic showed attractive color, low shrinkage and low hardness.•Infrared hot air dried garlic had better bioactive compound and antioxidant quality.•Relative humidity dried garlic showed the highest rehydration capacity.
Various drying techniques play an important role in foodstuff preservation. However, the role of different drying techniques on garlic quality is limited. The purpose of this study was to investigate the effect of vacuum freeze-drying (VFD), hot air drying (HAD), infrared hot air drying (IRHAD), relative humidity drying (RHD) and pulsed vacuum drying (PVD) on the physical, rehydration, flavor, bioactive compounds and antioxidant characteristics of garlic slices. Results showed that garlic slices treated with VFD had an attractive color, low shrinkage, low hardness, and the lowest rehydration capacity. The volume shrinkage ratio, thermal stability and storage stability of garlic slices after HAD were the highest. Different dried garlic samples had different specific flavor fingerprints. IRHAD and RHD dried samples showed the highest rehydration capacity, content of bioactive compounds and antioxidant activity. The findings could provide a scientific basis to help in future large-scale production of good quality dried garlic products.