Nutrition/Health Session
Moritz Krahl, Radeberger Gruppe, Frankfurt am Main, Germany
Co-author(s): Werner Back, TU München, Freising, Germany
ABSTRACT: Nowadays our nutrition is mainly based on only
three cereals: wheat, rice, and corn. They contribute over 75% to the
world’s starch production. At the same time diseases caused by wrong or
unbalanced diets are becoming a severe problem in Western countries. In
this regard the enrichment of soluble dietary fiber in the malting
process with the objective of providing their health-beneficial effects
to the consumer is a possible approach to better nutrition. Arabinoxylan
(AX) and fructan, two health-beneficial dietary fiber fractions have
been measured during the entire malting and brewing process. The total
AX in barley, wheat, rye, triticale, oats, and spelt wheat did not
change during the malting process. Water-extractable arabinoxylans
(WEAX) increased during malting, and the influence of the germination
parameters time, temperature, and moisture content was determined for
each of the cereals. The malting process is influenced by the quality of
the raw material and by several process parameters (e.g., moisture,
temperature, and time); in addition changes in dietary fiber content
depend on the same variables. To reduce the necessary number of trials
for the evaluation of optimal conditions we used software for the design
of experiments. This software supports several different statistical
approaches like various factorial designs or response surface methods
(RSM). With RSM the interactive effects of various process conditions
are modeled empirically. WEAX increased during germination in all malted
cereals. Kilning had no effect on the amount of WEAX in most cereals.
Only in rye did WEAX content increased by 30% during kilning. At the
same time the viscosity of Congress wort decreased. The probable
explanation for this phenomenon is a cleaving of diferulic acid-bridges
by the heat of the kilning process. These cross-linkages have been found
only in WEAX of rye. Using optimum malting parameters WEAX can increase
up to threefold the level found in unmalted kernels. Malting did not
affect the fructan content of most cereals, so no losses of this dietary
fiber fraction were observed. In spelt wheat the fructans increased
during standard malting, and the final level was 67% higher than in the
raw material. During the brewing process only mashing had an influence
on AX content. During lautering, wort boiling, fermentation, and storage
no changes were observed. Fructans were not influenced by mashing, wort
boiling, and lautering. During fermentation and storage more than 90%
of the fructans found in cooled wort were fermented by the yeast. The
experiments showed that malting is an effective way to enrich WEAX in
cereals and fructans in spelt wheat. In the brewing process the final
WEAX concentrations depend on the raw materials and not on the mashing
parameters.
Moritz Krahl was born in Schwetzingen, Germany.
After passing the German Abitur (A levels) in 2000, he began studying
brewing and beverage technology at Technische Universität München in
Weihenstephan, Germany. In 2004 he graduated with a B.S. degree and in
2005 with a Dipl.-Ing. (graduate engineer) degree. From 2005 to 2010
Moritz worked on his Ph.D. on “Functional Beverages Based on Malted
Cereals and Pseudocereals” at the Institute for Brewing and Beverage
Technology in Weihenstephan. From 2010 to 2011 he worked as head
engineer for plant and process optimization for MEG. In October 2011
Moritz joined the Radeberger Group with key responsibility in product
and process development for new beverages.
VIEW PRESENTATION 180
