[Show abstract][Hide abstract] ABSTRACT: Lactobacillus plantarum VTT E-78076 (E76) and Pediococcus pentosaceus VTT E-90390 (E390) starter cultures were added to the steeping water of normal malting barley in order to balance the microbial community and to enhance malt processability. In this study, we also investigated the effects of lactic acid-acidified MRS-spent medium (MRS-LA) on malting performance. Malting trials with five different two-row barley varieties were carried out in 25 kg pilot scale. The starter cultures promoted yeast growth during malting and restricted the growth of harmful bacteria and Fusarium fungi. Furthermore, they had positive effects on malt characteristics. Reduction in wort viscosity and beta-glucan content and enhanced xylanase and microbial beta-glucanase activities were observed. Starter cultures notably improved lautering performance. Some of the beneficial effects were due to the lactic acid and low pH, as similar effects were obtained with MRS-LA. Starter cultures offer a tool for tailoring of malt properties.
Full-text · Article · Jun 2006 · Journal of Agricultural and Food Chemistry
[Show abstract][Hide abstract] ABSTRACT: The objective of this work was to compare the chemical and physical quality of husks of barleys with high and low levels of husk damage and to develop analytical methods for breeders and maltsters to evaluate the potential for husk damage. For good husk adherence, the chemical and microscopic analyses indicated that the physical structure of the husk is more important than its chemical composition. The cementing layer was stained red with Oil Red O, indicating that it is a cutineous substance. Microscopic evaluation showed that the husk usually did not separate along the cementing layer between the pericarp and the husk. Instead, the husk layers with large thin-walled cells were broken. A thin dorsal vein and a thin layer of parenchyma in the lemma appeared to indicate less easily damaged husk than did a strong dorsal vein and thick layer of large thin-walled parenchyma cells. Analytical methods were developed for visual and mechanical evaluation of the husk damage. The most critical steps of husk damage during malting operations were identified by using a visual method. The results can be used for the development of the best practices in the entire production chain. Evaluation of barleys grown in various locations and crop years confirmed that husk quality is a varietal characteristic, but growing conditions also have a marked effect on it.
No preview · Article · Jan 2005 · Journal of the American Society of Brewing Chemists