Research on Processing Bergamot by Microwave Combined with Vacuum Freeze-Drying

[Objective] To explore the effects of combined drying methods on processing of bergamot slices.[Method] Taking vacuum freeze-drying time and rehydration rate as main indexes,processing bergamot slices by drying method of microwave combined with vacuum freeze-drying and optimum of parameters through L9(33) orthogonal experiments was studied;meanwhile,taking VC content and essential oil content of bergamot product as indexes,the effect of quality by different drying methods was explored in this paper.[Results] Compared with vacuum freeze-drying,combined drying method can shorten freeze-drying time and improve rehydration rate significantly,under conditions of microwave 560 W,microwave processing time 2.5 min and material thickness 7 mm,the whole freeze-drying time is 9.8 h.[Conclusion] Combined drying method can improve products qualities better than microwave drying and vacuum freeze-drying.