KARL J. SIEBERT (1), Aleksander Egi (2), Robert McCaig (2)
(1) Cornell University, Geneva, NY; (2) Canadian Malting Barley Technical Centre, Winnipeg, MB, Canada
Barley samples were pilot malted at the Canadian Malting Barley
Technical Centre, where analyses of the barleys and malts were
performed. The barley data contained 8 observations each for approx. 360
samples; 14 cultivars and 9 crop years were well represented. Principal
components analysis (PCA) applied to this data found three significant
PCs, indicating that the 8 measurements actually contained information
on three fundamental properties. The first PC was heavily influenced by
assortment and 1,000-kernel weight. The second PC was influenced
positively by germination and negatively by moisture content. The third
PC was mainly related to protein content. Pattern recognition procedures
were partially successful in classifying barley samples by cultivar or
crop year. When 14 measurements for 538 malt samples were analyzed with
PCA, it appeared there were five fundamental properties. The first PC
was heavily influenced negatively by friability and positively by
β-glucans, viscosity, and fine/coarse difference; essentially, this
represents modification. The second component was mainly influenced by
α-amylase and diastatic power and the third by both fine and coarse
extract. The fourth PC was influenced positively by soluble protein and
wort color and negatively by wort pH. The fifth PC was heavily
influenced by Kolbach index and free amino nitrogen. Relationships
between the barley and malt samples were sought using partial least
squares regression.
Karl Siebert received a Ph.D. degree in biochemistry from Penn State
in 1970. He then joined the Stroh Brewery Company in Detroit, MI, where
he spent 18 years and held positions ranging from research associate to
director of research. In 1990, Karl joined Cornell University as a
professor of biochemistry in the Department of Food Science and
Technology. He served five years as department chair and now has a
predominantly research commitment. Karl is active as a consultant in
beverage technology and chemometrics. He twice received MBAA
Presidential Awards for papers he presented, and he and his colleague,
Penny Lynn, received the ASBC Eric Kneen Memorial Award (for the best
paper in the ASBC Journal in the prior year) three times. Karl
was made an Honorary Professor of the Moscow (Russia) State Academy of
Food Processing in 1996, and in 1999 he received the ASBC Award of
Distinction. He is currently a member of the ASBC Journal Editorial
Board and the ASBC Foundation Board. Karl’s research interests involve
foam and haze in beverages, perception of astringency and other flavors,
the application of chemometric methods in food science, and assessment
of microbiological risk.
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