title: Effect of different heating conditions on the extractability of barley hordeins.
abstract: The extractability of hordeins from barley grains was investigated after wet and dry heating conditions. It was found that the amount of hordeins extractable with 55% 2-propanol decreased in a time-dependent manner after barley grains were steamed (wet heating), whereas hordeins showed no effect from heating in an oven at 100 degress C for up to 120 min (dry heating). The result of SDS-PAGE analysis revealed that B-hordein decreased time-dependently in extractability with wet heating and had almost completely disappeared by 60 min, but C-hordein remained unchanged until 120 min. With the use of the hordein fraction prepared from the nonheated barley grains, it was confirmed that B-hordein suspended in boiling water lost solubility in 55% 2-propanol. The insolubilized B-hordein was redissolved by the addition of 2-mercaptoethanol to 1%, which suggested that the intermolecular disulfide bonds would play a significant role in the loss of solubility. On the other hand, C-hordein did not lose solubility from being heated under the same conditions.
authors.affiliation: Division of Life Science, Graduate School of Science and Technology, Kobe University, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Nakai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
authors.forename: Gen-ichi
authors.initials: G
authors.lastname: Danno
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005983:Glutens; D001467:Hordeum / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D010940:Plant Proteins / Q000302:isolation & purification*; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D012997:Solvents; D014867:Water; D005983:Glutens; D019840:2-Propanol