Effects of phenolic compounds on the browning of cooked barley.
Barley grain products undergo browning when cooked. To evaluate effects of phenolic compounds on browning, various amounts of (+)-catechin, proanthocyanidins, or related phenolic compounds were added to aqueous barley extracts or barley pastes, which were heated at 90 degrees C for 1 or 2 h, respectively. In barley extract, (+)-catechin, procyanidin B3 (PCB3), prodelphinidin B3 (PDB3), and a trimer of gallocatechin-gallocatechin-catechin (PDT1) dose-dependently elevated absorbance at 420 nm after heating. PDB3 caused browning faster than PCB3 and (+)-catechin. In barley paste, PDB3 and PDT1 decreased the L* value and increased the a* and b* values of the paste dose-dependently after heating and PCB3 and (+)-catechin did so to a lesser extent. Caffeic acid promoted the browning in both of the extract and paste, while protocatechuic acid, eriodictyol, and (+)-taxifolin promoted it in the extract and myricetin and quercetin promoted it in the paste. Compounds promoting browning have catechol or pyrogallol structures in common.
Kohyama
Noriko
N
National Institute of Crop Science, NARO, Tsukuba, Ibaraki 305-8518, Japan. norikok@affrc.go.jp
Fujita
Masaya
M
Ono
Hiroshi
H
Ohnishi-Kameyama
Mayumi
M
Matsunaka
Hitoshi
H
Takayama
Toshiyuki
T
Murata
Masatsune
M
D002392:Catechin / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D001467:Hordeum / Q000737:chemistry*; D006358:Hot Temperature; D015416:Maillard Reaction / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry; D044945:Proanthocyanidins / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D044945:Proanthocyanidins; D002392:Catechin