Characterization of 9-fatty acid hydroperoxide lyase-like activity in germinating barley seeds that transforms 9(S)-hydroperoxy-10(E),12(Z)-octadecadienoic acid into 2(E)-nonenal.
Previously, we reported that 2(E)-nonenal, having a low flavor threshold (0.1 ppb) and known as the major contributor to a cardboard flavor (stale flavor) in stored beer, is produced by lipoxygenase-1 and a newly found factor named 9-fatty acid hydroperoxide lyase-like (9-HPL-like) activity in malt. To assess the involvement of 9-HPL-like activity in beer staling, we compared the values of the wort nonenal potential, an index for predicting the staleness of beer, with the lipoxygenase and 9-HPL-like activity of 20 commercial malts. There was a significant correlation between the malt 9-HPL-like activity and the values of wort nonenal potential (r=0.53, P<0.05), while the correlation between malt lipoxygenase activity and the wort nonenal potential was statistically insignificant. Analysis of the partially purified 9-HPL-like activity from embryos of germinating barley seeds indicated that 9-HPL-like activity consisted of fatty acid hydroperoxide lyase and 3Z:2E isomerase.
Kuroda
Hisao
H
Frontier Laboratories of Value Creation, SAPPORO BREWERIES LTD, Shizuoka 425-0013, Japan. Hisao.Kuroda@sapporobeer.co.jp
Kojima
Hidetoshi
H
Kaneda
Hirotaka
H
Takashio
Masachika
M
D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism; D000447:Aldehydes / Q000737:chemistry* / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D018525:Germination; D001467:Hordeum / Q000201:enzymology*; D007535:Isomerases / Q000737:chemistry / Q000378:metabolism; D008041:Linoleic Acids / Q000737:chemistry* / Q000378:metabolism; D008054:Lipid Peroxides / Q000737:chemistry* / Q000378:metabolism; D012639:Seeds / Q000201:enzymology*
C506899:9-hydroperoxy-10,12-octadecadienoic acid; D000447:Aldehydes; D008041:Linoleic Acids; D008054:Lipid Peroxides; C013166:2-nonenal; C049606:9-hydroperoxy-11,12-octadecadienoic acid; D003577:Cytochrome P-450 Enzyme System; D000446:Aldehyde-Lyases; C054540:hydroperoxide lyase; D007535:Isomerases