title: Optimization of microwave vacuum drying of lotus (Nelumbo nucifera Gaertn.) seeds by response surface methodology.
abstract: Drying is the main process used to treat lotus seeds for storage. In this study, response surface methodology was used to optimize processing methods for microwave vacuum (MWV) drying of lotus seeds and to create a desirable product. A central composite design with three important factors: microwave output power (2.0-4.0 kW), vacuum degree (-0.070 to -0.090 MPa) and on/off ratio (68/52 s to 99/21 s) was used to study the response variables of drying time, shrinkage ratio, rehydration ratio and whiteness index. The optimum conditions for MWV drying of lotus seeds were determined to obtain a minimal drying time, minimal shrinkage ratio, maximum rehydration ratio and maximum whiteness index. The optimum drying conditions were found to be: microwave output power 3.2 kW, vacuum degree -0.083 MPa and on/off ratio 94/26 s. Under these optimal conditions, drying time, shrinkage ratio, rehydration ratio and whiteness index were found to be 10 min, 37.66%, 157.1% and 68.83, respectively.
authors.affiliation: College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, PR China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Tian
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shaoxiao
authors.initials: S
authors.lastname: Zeng
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Zheng
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Zhebin
authors.initials: Z
authors.lastname: Guo
authors.forename: Yufei
authors.initials: Y
authors.lastname: Lin
authors.forename: Baodong
authors.initials: B
authors.lastname: Zheng
mesh_terms: D055598:Chemical Phenomena; D002681:China; D003116:Color; D005519:Food Preservation / Q000295:instrumentation / Q000379:methods*; D061353:Food Storage; D006358:Hot Temperature; D008516:Medicine, Chinese Traditional; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D031653:Nelumbo / Q000737:chemistry* / Q000648:ultrastructure; D012639:Seeds / Q000737:chemistry* / Q000648:ultrastructure; D013223:Statistics as Topic; D013499:Surface Properties; D013997:Time Factors; D014618:Vacuum; D014867:Water / Q000032:analysis
chemical_list: D014867:Water