Malt and Grains Session
Glen Fox, The University of Queensland, Toowoomba, Queensland, Australia
Co-author(s): Loraine Watson, University of Queensland, Toowoomba,
Australia; Alison Kelly, DEEDI, Toowoomba, Australia; Cheng Dao Li,
DAFWA, Perth, Australia; Wendy Lawson, DEEDI, Warwick, Australia
ABSTRACT: Malting barley grain buyers purchase grain that
meets a number of physical and chemical specifications, such as grain
size and protein content, respectively. These traits are measured using
objective testing. However, there are grain traits that are measured
using subjective (visual) assessment. Black point (BP), also called
black tip or germ-end staining, is one of these subjective traits. BP is
a brown/black discoloration over the germ (embryo) of the grain. In
Australia, less then 5% of any malting barley load can have BP to reach
domestic malting specifications. For some export markets, 0% is the
standard. Historically, BP has been associated with fungal infection and
in some cases with unusual environmental conditions. Even a slight
level of BP is viewed as a defect in malting barley. In our study, we
have used near infrared spectroscopy (NIRS) to ascertain key wavelengths
to assess BP with a view to develop an objective single kernel
assessment system. Single kernels plus and minus BP, as well as
individual husks removed from BP plus and minus kernels, were scanned
using a Foss NIRSystems 6500 (400–2,498 nm) at 2 nm increment (WinISI
V1.5). The spectral data showed significant changes in wavelengths
around 1,868–1,888 nm that are associated with C=O and NH bonds. These
chemicals bonds are associated with fiber (cellulose and lignin) and
protein in the single kernels and single husk scans. There was an
increase in other chemical regions in the BP plus single kernels, for
example proteins, which would be associated with biological activity of
the germ producing a chemical response to the induced stress (fungal
attack or physiological stress). The results showed the potential to use
NIRS technology to assess for BP in single kernels. However, at this
stage there is one major issue to overcome and that is the orientation
of the kernel as it is seen by the NIR instrument. The instrument must
see the germ to be able to collect spectra associated with BP. While
this issue presents a challenge in engineering, the opportunity to
assess single kernels that could be segregated from a bulk sample would
improve the subjective assessment and provide samples to understand the
effect of BP on quality post-harvest, in storage, and on malting and
brewing quality.
Glen Fox joined the University of Queensland,
Queensland Alliance for Agriculture and Food Innovation, in 2010 after
25 years of conducting research projects with the Queensland government.
His areas of research are in cereal quality, specifically barley,
wheat, sorghum, and maize. He has a vast amount of knowledge in
value-added cereals, in particular barley, malt, and beer quality. He
has been a project leader in numerous national grains projects for
barley. His main research area has been near-infrared spectroscopy
(NIRS), with calibration development in cereals (wheat, barley,
triticale, sorghum, and maize), peanuts, soybeans, and animal feed.
Currently, Glen is researching use of NIRS on single kernels of grain,
as well as hyperspectral imaging of single kernels. He has more than 150
publications, including book chapters, journal articles, and conference
papers. He has also supervised many post-graduate students in Australia
and overseas. Glen is on a number of technical committees, including
the Institute of Brewing & Distilling Asia-Pacific Analytical
Methods sub-committee and has been on a number of specific
sub-committees for the American Society of Brewing Chemists. In 2011, he
was made an adjunct associate professor at Stellenbosch University in
South Africa for his contribution to the science of NIRS in cereal and
grains.
VIEW PRESENTATION 153
