Isolation of an in vitro and ex vivo antiradical melanoidin from roasted barley.
The antiradical properties of water-soluble components of both natural and roasted barley were determined in vitro, by means of DPPH* assay and the linoleic acid-beta-carotene system, and ex vivo, in rat liver hepatocyte microsomes against lipid peroxidation induced by CCl4. The results show the occurrence in natural barley of weak antioxidant components. These are able to react against low reactive peroxyl radicals, but offer little protection against stable DPPH radicals deriving from peroxidation in microsomal lipids. Conversely, roasted barley yielded strong antioxidant components that are able to efficiently scavenge free radicals in any system used. The results show that the barley grain roasting process induces the formation of soluble Maillard reaction products with powerful antiradical activity. From roasted barley solution (barley coffee) was isolated a brown high molecular mass melanoidinic component, resistant to acidic hydrolysis, that is responsible for most of the barley coffee antioxidant activity in the biosystem.
Papetti
Adele
A
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Daglia
Maria
M
Aceti
Camilla
C
Quaglia
Milena
M
Gregotti
Cesarina
C
Gazzani
Gabriella
G
D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D001713:Biphenyl Compounds; D002251:Carbon Tetrachloride; D016166:Free Radical Scavengers / Q000032:analysis / Q000494:pharmacology; D001467:Hordeum / Q000737:chemistry*; D006358:Hot Temperature; D019787:Linoleic Acid; D015227:Lipid Peroxidation / Q000187:drug effects; D015416:Maillard Reaction; D008862:Microsomes, Liver / Q000187:drug effects; D010851:Picrates; D011108:Polymers / Q000302:isolation & purification* / Q000494:pharmacology; D051381:Rats; D019207:beta Carotene
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D011108:Polymers; C011908:melanoidin polymers; D019207:beta Carotene; D019787:Linoleic Acid; D002251:Carbon Tetrachloride; C004931:1,1-diphenyl-2-picrylhydrazyl