title: Porosity changes and retention of ginsenosides in North American ginseng root using different dehydration processes.
abstract: Air drying (AD), freeze-drying (FD), and vacuum-microwave drying (VMD) were applied to fresh North American ginseng roots to evaluate the effect of different drying techniques on pore characteristics and the subsequent recovery of ginsenoside content. FD ginseng root produced the lowest reductions in both total moisture content and water activity (P < 0.05), with no differences noted between Ontario or British Columbia ginseng. Ginseng roots from Ontario and British Columbia sources were therefore pooled to conduct the root porosity and ginsenoside measurements. Among samples, FD ginseng obtained the highest total porosity followed by VMD and AD, respectively (P < 0.05). All dehydrated samples had a porous structure with sizes that ranged from 0.002 μm to 172 μm, dominated by macropores (>1.5 μm). Pore characteristics of dried ginseng root were shown to affect recovery of ginsenosides, with the general trend being an increase in total porosity resulting in an increase in total ginsenoside recovered. High performance liquid chromatography results obtained on specific ginsenosides showed that AD of ginseng root resulted in the lowest recovery of total ginsenosides, most notably, Rg1 and Rb1, followed by VMD and FD, respectively. There was no specific difference in total ginsenoside recovery from roots dried at increasing power of VMD.
authors.affiliation: Food Science, Food, Nutrition, and Health Program, Faculty of Land and Food System, Univ. of British Columbia, 2205 East Mall, UBC, Vancouver, Canada V6T-1Z4.
authors.forename: Monica
authors.initials: M
authors.lastname: Purnama
authors.forename: Parastoo
authors.initials: P
authors.lastname: Yaghmaee
authors.forename: Tim D
authors.initials: TD
authors.lastname: Durance
authors.forename: David D
authors.initials: DD
authors.lastname: Kitts
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005519:Food Preservation / Q000379:methods*; D005612:Freeze Drying; D036145:Ginsenosides / Q000032:analysis*; D008872:Microwaves / Q000009:adverse effects; D009656:North America; D005894:Panax / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D018517:Plant Roots / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D016062:Porosity; D013499:Surface Properties; D014618:Vacuum; D014867:Water / Q000032:analysis
chemical_list: D036145:Ginsenosides; D014867:Water; C442759:ginsenoside Rb1; C035054:ginsenoside Rg1