title: Removal of off-flavours from radish (Raphanus sativus L.) anthocyanin-rich pigments using chitosan and its mechanism(s).
abstract: In this paper, we examined the role of chitosan in the removal of off-flavours from radish anthocyanin-rich pigments and studied the mechanisms of the process. Four radish glucosinolates (glucoraphenin, dehydroerucin, glucobrassicin, and glucoerucin) were identified by LC-MSn from root extracts and dehydroerucin was found to be the major glucosinolate in red radish roots. Application of chitosan with 76%, 83% or 89% deacetylation in radish extracts attributed to 26%, 35% or 43% adsorption rate for glucosinolates, and 28%, 26% or 22% for anthocyanins, respectively. HS-SPME/GC-MS analysis demonstrated that the concentration of volatile compounds decreased by 70%, resulting in the loss of odorous compounds. The changes in chitosan spectra before/after adsorption and after desorption at 1590 and 3360cm(-1) and at broad bands from 2600 to 2000cm(-1) suggest that the dominant adsorption mechanisms of glucosinolates on chitosan may be electrostatic attractions, including hydrogen bonds and charge neutralisation.
authors.affiliation: Department of Food Science and Engineering, School of Food and Biological Engineering, Jiangsu University, Jiangsu 212013, China.
authors.forename: Ruichang
authors.initials: R
authors.lastname: Gao
authors.forename: Pu
authors.initials: P
authors.lastname: Jing
authors.forename: Siyu
authors.initials: S
authors.lastname: Ruan
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zhao
authors.forename: Zhan
authors.initials: Z
authors.lastname: Cai
authors.forename: Bingjun
authors.initials: B
authors.lastname: Qian
mesh_terms: D000327:Adsorption; D000872:Anthocyanins / Q000032:analysis*; D048271:Chitosan / Q000737:chemistry*; D005511:Food Handling; D008401:Gas Chromatography-Mass Spectrometry; D005961:Glucosinolates / Q000737:chemistry* / Q000302:isolation & purification; D009812:Odorants / Q000032:analysis; D031224:Raphanus / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D000872:Anthocyanins; D005961:Glucosinolates; D048271:Chitosan
keywords: Adsorption mechanism; Anthocyanin; Chitosan; Glucosinolate; Radish