Journal Overview
Publication Notice
Table of Contents
Search Abstracts
Sample Issue
Subscribe
Masthead
Editorial Policy
Author Instructions
VIEW ARTICLE DOI: 10.1094/ASBCJ-56-0032
Synthesis of Limit Dextrinase in Germinated Barley Kernels and Aleurone Tissues (1). S. W. Schroeder and A. W. MacGregor, Canadian Grain Commission, Grain Research Laboratory, 1404-303 Main Street, Winnipeg, Manitoba, R3C 3G8, Canada. (1) Contribution No. 764 of the Canadian Grain Commission, Grain Research Laboratory, 1404-303 Main Street, Winnipeg, Manitoba, R3C 3G8, Canada. J. Am. Soc. Brew. Chem. 56(1):32-37, 1998. Accepted December 10, 1997. Copyright 1998 Department of Agriculture and Agri-Food, Government of Canada.
The development
and secretion
of alpha-amylase
and limit dextrinase
activities in
de-embryonated
half-kernels
of Harrington
barley, incubated
in the presence
and absence
of gibberellic
acid (GA(3)),
were studied.
Development
of the enzymes
in germinated
barley was also
investigated.
Enzyme levels
in the aleurone
and starchy
endosperm tissues
of half-kernels
and germinated
barley were
measured, and
proportions
of limit dextrinase
in aleurone
and starchy
endosperm tissues
of different
barley varieties
were determined.
Aleurones of
de-embryonated
barley half-kernels
produced low
levels of both
alpha-amylase
and limit dextrinase
in the absence
of GA(3), although
secretion of
the enzymes
from the aleurones
under these
conditions did
not appear to
be significant.
Added GA(3)
enhanced the
development
of both enzymes
in half-kernels
as well as in
germinated seeds.
Secretion of
alpha-amylase
from aleurones
of germinated
seeds and de-embryonated
half-kernels
in the presence
of GA(3) was
very rapid,
but GA(3) did
not appear to
have an effect
on the secretion
of limit dextrinase
from aleurones,
which was very
slow in both
de-embryonated
half-kernels
and germinated
barley. The
total limit
dextrinase activity,
and the proportions
of limit dextrinase
found in the
aleurone and
starchy endosperm
tissues, varied
in different
varieties of
barley. Keywords:
Aleurones, alpha-Amylase,
Germination,
Gibberellic
acid, Limit
dextrinase,
Starchy endosperms.
Se estudió
el desarrollo
y secreción
de alpha-amilasa
y dextrina límite
activadas en
mitades de granos
sin embrión
de cebada Harrington,
incubados en
presencia y
ausencia de
ácido
giberélico
(GA(3)), también
fue investigado
el desarrollo
de la enzima.
Fueron medidos
los niveles
de enzima en
la aleurona
y en tejidos
de endospermo
de las mitades
de grano y cebada
germinada, y
fueron determinadas
las proporciones
de dextrinasa
límite
en aleurona
y endospermo
de diferentes
variedades de
cebada. Las
aleuronas de
las mitades
de granos sin
embrión
fueron capaces
de producir
bajos niveles
de ambas, alpha-amilasa
y destrinasa
límite
en ausencia
de GA(3), aunque
la secreción
de la enzima
de las aleuronas
bajo estas condiciones
no parece ser
significante.
La adición
de GA(3) incrementa
el desarrollo
de ambas enzimas
en las mitades
de granos, así
como en las
semillas germinadas.
La secreción
de alpha-amilasa
de aleuronas
de semillas
germinadas y
mitades de granos
sin embrión
en presencia
de GA(3) fue
muy rápida,
pero el GA(3)
parece no tener
un efecto en
la secreción
de dextrinasa
límite
de aleuronas,
la cual fue
muy lenta en
ambas mitades
de granos sin
embrión
y cebada germinada.
La actividad
total de dextrinasa
límite
y la proporción
de dextrinasa
límite
encontradas
en aleuronas
y tejidos de
endospermo,
varía
en las diferentes
variedades de
cebada.
| Buy this article. |
|
A subscription to the Journal of the American Society of Brewing Chemists is complimentary with membership to the ASBC. The ASBC Journal publishes scientific papers, review articles, and technical reports dealing with the chemistry and microbiology of brewing ingredients and relevant technology, as well as the analytical techniques used in the malting and brewing industry. |