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ABSTRACT: Hordatine A β-D-glucopyranoside was isolated from ungerminated barley grains for the first time and identified by MS spectrometry and one- and two-dimensional NMR spectroscopy. This compound was observed after 20 days after flowering (DAF) and was most abundant at 35 DAF when the dry weight of grains reached a maximum. The contents of the compound markedly decreased when grains were pearled from 85% to 70% yield, suggesting that the compound is localized in the aleurone layer. The compound was commonly observed in ungerminated mature grains among 10 cultivars and its contents ranged from 103 to 254 nmol/g dry weight. Because hordatines have been reported to have antifungal activities, the compound may act as an antifungal component in the latter half of the maturing stages and in mature barley grains.
Journal of Agricultural and Food Chemistry 01/2013; · 2.82 Impact Factor
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ABSTRACT: 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.
Journal of Agricultural and Food Chemistry 08/2009; 57(14):6402-7. · 2.82 Impact Factor
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ABSTRACT: Purple waxy hull-less barley cv. Daishimochi accumulates purple pigments in the stem, awn, lemma, palea, and pericarp during seed maturation. Four major anthocyanin constituents from the grains of cv. Daishimochi were isolated and identified as cyanidin 3-O-(3,6-di-O-malonyl-beta-D-glucopyranoside) (55%), cyanidin 3-O-(6-O-malonyl-beta-D-glucopyranoside) (21%), cyanidin 3-O-(3-O-malonyl-beta-D-glucopyranoside) (12%), and cyanidin 3-O-beta- d-glucopyranoside (4%) by mass spectrometry and one- and two-dimensional NMR spectroscopy. These anthocyanins were observed after 28 days after flowering (DAF); they were most abundant at 35 DAF when the dry weight of grains was maximum. This accumulation time was later than that of proanthocyanidins, which are the most abundant polyphenol constituents in barley grains. These anthocyanins, especially cyanidin 3-O-(3,6-di-O-malonyl-beta- d-glucopyranoside), decreased at 42 DAF and during drying preparation after harvest. Most anthocyanins are localized in the outer parts of grains and distributed into bran by the pearling process. Whole grain flour and bran of cv. Daishimochi are good sources of malonylated cyanidin derivatives.
Journal of Agricultural and Food Chemistry 08/2008; 56(14):5770-4. · 2.82 Impact Factor
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ABSTRACT: The polyphenol content in pearl barley, which is highly correlated to a browning reaction after heat treatment, was investigated
using 1,347 cultivated barley varieties (H. vulgare) and two wild accessions (H. vulgare subsp. spontaneum) collected from different areas of the world. The polyphenol content in the cultivated barley shows a wide variation ranging
from 0.19 to 0.75 mg/g with a nearly normal frequency distribution. The polyphenol content in the hulless varieties from Japan
and Korea was low. On the other hand, the polyphenol content in wild barley was about two times higher than the average value
recorded in cultivated barley. Based on HPLC analysis, five lowest-polyphenol content local varieties do not represent proanthocyanidin-free
mutants.
Euphytica 01/2002; 124(1):55-58. · 1.55 Impact Factor
