Reduction of Malting Loss Using Lactobacilli
Peer-Reviewed Paper
MBAA TQ vol. 44, no. 2, 2007, pp.
84-92 |
VIEW ARTICLE Beatus D. Schehl (1,3), M. Almudena Soriano (2), Elke K. Arendt (1), and
Helge M. Ulmer (1). 1. Department of Food and Nutritional Sciences, National
University of Ireland, University College Cork, Cork, Ireland. 2. Department of
Analytical Chemistry and Food Technology, University of Castilla-La Mancha,
Ciudad Real, Spain. 3. Bio Transfer Unit, National University of Ireland,
University College Cork, Cork, Ireland.
Abstract
The malting and brewing industry is highly dependent on innovative solutions
to improve the quality of malt and beer. To increase the competitiveness of the
malting industry, it is essential to reduce the production costs of malt as much
as possible. A significant amount of the original barley weight is lost (approx.
4�10% due to removal of rootlets) during the malting process, termed malting
loss. The objective of this project was to use selected lactic acid bacteria as
starter cultures during the malting process to significantly reduce malting loss
and retain malt quality. During a pilot-plant screening, Lactobacillus
plantarum 15GR was selected, since a reduction in rootlet growth under
laboratory conditions was observed. This strain, which produces anti-rootlet
components, was compared with a number of lactic acid bacteria, a chemical
rootlet growth inhibitor (potassium bromate), a control containing lactic acid,
and an unacidified control. The quality of the malt was analyzed using a wide
range of EBC methods. The enzymatic activity of the malt was also determined.
The pilot-scale malting trials revealed that the malting loss of malt treated
with L. plantarum 15GR was reduced by 50% compared with the controls
while good malt quality was maintained. L. plantarum 15GR performed
significantly better than the chemical rootlet inhibitor (potassium bromate)
currently employed by the industry.
Keywords: barley, lactic acid bacteria, Lactobacillus plantarum, malt,
malting, malting loss, potassium bromate, rootlet, starter culture, wort quality
S�ntesis
Las malter�as y cervecer�as son altamente dependientes de soluciones
innovativas para mejorar la calidad de la malta y de la cerveza. Para mejorar la
competitividad de la industria maltera, es esencial reducir lo m�s posible los
costos de producci�n. Una cantidad significativa del peso original de la cebada
se pierde durante el proceso de malteo (4�10% debido a la remoci�n de las
raicillas). El objetivo de este proyecto consisti� en utilizar cultivos
particulares de bacterias de �cido l�ctico como cultivo iniciador durante el
malteo para reducir estas p�rdidas de malteo significativamente a la vez de
preservar la calidad de la malta. Durante una prueba inicial se utiliz�
Lactobacillus plantarum 15GR debido a que se observ� una reducci�n en el
crecimiento de las raicillas en pruebas de laboratorio. Esta raza (que produce
componentes antiraiz) fue comparada con otras razas de bacteria de �cido
l�ctico, un inhibidor qu�mico de crecimiento de raicillas (bromato de potasio),
un control con �cido l�ctico y un control no acidificado. Se midi� la actividad
enzim�tica de estas maltas adem�s de analizar la calidad de la malta utilizando
varios m�todos de la EBC. Las pruebas de malteo a nivel de planta piloto
demostr� que la p�rdida de malteo en la prueba con L. plantarum 15GR se
redujo por 50% comparado con los controles, manteni�ndose la buena calidad de la
malta. L. plantarum 15GR se desempe�� significativamente mejor que el
inhibidor qu�mico de crecimiento de raicillas (bromato de potasio) utilizado de
momento en las malter�as.
Palabras claves: bacteria de �cido l�ctico, bromato de potasio, calidad de
mosto, cebada, cultivo iniciador, Lactobacillus plantarum, malta, malteo,
p�rdidas de malteo, raicillas
