Annual Progress Report on Malting Barley Research March, 2007

the lead institution for this project. The overall theme of the barley CAP is to integrate
and utilize state-of-the-art genomic tools and approaches in plant breeding programs,
thereby facilitating the development of superior barley cultivars and access to
agronomic and economically important genes.
(C) Determination of Factors Controlling Malt Extract (Dr Yin Li). Using a
chemometrics approach, we hope to define analytical and process components which
have the greatest influence on the development of malt extract. This is valuable, given
the greater demands for consistency and uniformity in malting, advances in malting
technology (process control), and the potential to improve our understanding of quality
through genomics. Common malt analytical procedures have origins in the late 1800’s
to 1940’s and have not significantly changed since adopted by ASBC. Extract is a
complex trait, and quantitative trait loci (QTL) for malt extract have been identified on
each of the 7 barley chromosomes. A statistical approach to factors contributing to
extract may also help to identify the type of genes that are of primary importance. The
overall objectives will be to statistically evaluate chemical and physical factors that
contribute to laboratory extract and its composition. Three separate studies have been
conducted to date.
• Part I was a study of how operational parameters of grind, grist:water ratio and
temperature profile impact the determination of laboratory extract and associated
wort quality parameters (Schwarz et al 2007).
• Part II was a study of factors influencing extract in a historical population of 16
six-rowed cultivars dating to 1910. Extract values in these samples range from 75
too 80%. A range of chemical and physical factors was evaluated across
modification levels. Research is approximately 80% complete.
• Part III was a study of factoring influencing extract in a single cultivar (Tradition).
Extract (CG) in the original unfractionated samples ranged from 77 to 80%.The
second study looked at a population of historical varieties dating back to 1910
(D) Bound Mycotoxins (Ms Zhou Bing). We have recently identified that barley can
contain significant amounts of bound DON that is not extractable under normal assay
conditions (room temperature extraction with acetonitrile:water). This “bound” DON can
represent a very small amount to almost 100% of the DON extracted under normal
conditions. The bound nature of the DON does not appear due to simple matrix effects,
and finer milling and heating during extraction have a negligible effect. Small but
significant amounts of bound DON can be released following treatment with amylolytic
enzymes. However, the largest amounts of bound DON are found following
hydrolysis/solvolysis of the sample in trichoro acetic acid.
The bound nature of the DON has a number of interesting implications. First, there is a
possibility that it might be released during digestion of grain based foods/feeds, or
during food processing. As an example the occasional increase in DON that is seen
during the malting of FHB contaminated grain, might be explained by release of bound
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