title: Effects of high hydrostatic pressure on structure and colour of red ginseng (Panax ginseng).
abstract: BACKGROUND
  The conventional method of processing ginseng (Panax ginseng) roots into red ginseng involves mainly heating and drying processes. In the present study, this method was modified by using high hydrostatic pressure (HHP) to improve the physicochemical characteristics of red ginseng.
  
  
  RESULTS
  The HHP process (600 MPa for 1 min) significantly improved the histological properties of red ginseng by increasing cellular disruption and release of cell contents. The total reducing sugar content was significantly (P < 0.05) higher (increased from 10.67 to 15.25 mg g(-1)) in red ginseng processed at 600 MPa for 1 min. Similarly, the total free amino acid content also increased significantly (from 2.81 to 7.77 mg g(-1)). The HHP process resulted in superior and more even colouration and gave an attractive visual appearance to red ginseng. The optical density at 420 nm and Hunter's colour a value (redness) of extracts prepared from red ginseng increased significantly (P < 0.05) with the application of HHP.
  
  
  CONCLUSIONS
  HHP-processed red ginseng has significantly higher reducing sugar and free amino acid contents together with a more compact cell structure and superior visual quality (brighter red colour). Hence the application of HHP in red ginseng processing can result in ginseng products of improved quality compared with those obtained by the conventional method.
authors.affiliation: Department of Food Science and Nutrition, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Kashif
authors.initials: K
authors.lastname: Ghafoor
authors.forename: Sun-Ok
authors.initials: SO
authors.lastname: Kim
authors.forename: Dong-Un
authors.initials: DU
authors.lastname: Lee
authors.forename: Kijun
authors.initials: K
authors.lastname: Seong
authors.forename: Jiyong
authors.initials: J
authors.lastname: Park
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D003116:Color; D003890:Desiccation; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D006874:Hydrostatic Pressure; D015416:Maillard Reaction; D008855:Microscopy, Electron, Scanning; D005894:Panax; D018517:Plant Roots / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D000596:Amino Acids; D002241:Carbohydrates