Influence of the malting parameters on the haze formation of beer after filtration

European Food Research and Technology (Impact Factor: 1.56). 10/2011; 233(4):587-597. DOI: 10.1007/s00217-011-1547-0


Malting changes the chemical and enzymatical composition of barley. During malting, enzymes are synthesized, cell walls (pentosans,
proteins, etc.) degraded and starch becomes available for enzymatic attack. The progress of germination defines the final
beer quality and processability in several aspects: mouthfeel, foam and haze formation (different proteins), processability
(viscosity caused by certain substances, like β-glucan), fermentation progress (FAN, sugar content), etc. The objective of
this research was to study the influence of different modified malt on turbidity in beer after filtration. This was achieved
by analyzing selected malts at different germination stages and afterward studying their influence on the final beer composition,
focusing on protein content and composition. Protein fractions were analyzed using a Lab-on-a-Chip technique, which separates
the proteins—based on their molecular weight—by capillary electrophoresis. This analysis was supported by the use of two-dimensional
gel electrophoresis (2D-PAGE). Additionally, common malt and beer analyses and turbidity and filterability measurements were
performed. The protein composition could be followed from malt to beer with both the Lab-on-a-Chip technique and 2D-PAGE.
No differences in protein composition could be seen in the final protein composition of the beer. However, it could be observed,
with Lab-on-a-Chip technique, that high amounts of a protein fraction with a size of 25–28kDa caused increased turbidity
in the beer.

KeywordsMalt–Proteins–Haze–Lab-on-a-Chip technique–2D-PAGE

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    • "They are required for yeast nutrition; they contribute to foam and are involved in the flavor development that malt contributes to beer and whiskey. The protein content of teff (11 %) is in the range (9.5 to 11.5 %) that a good quality malting material should possess to yield the above-mentioned quality-attributes (Asano and Hashimoto 1980; Bamforth 1985; Bishop 1930; Chen et al. 2006; Kunze 2004; Steiner et al. 2011). Thus, its protein content is an indicator for production of good quality gluten-free malt from teff grains. "
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    ABSTRACT: The demand for gluten-free foods is certainly increasing. Interest in teff has increased noticeably due to its very attractive nutritional profile and gluten-free nature of the grain, making it a suitable substitute for wheat and other cereals in their food applications as well as foods for people with celiac disease. The main objective of this article is to review researches on teff, evaluate its suitability for different food applications, and give direction for further research on its applications for health food market. Teff is a tropical low risk cereal that grows in a wider ecology and can tolerate harsh environmental conditions where most other cereals are less viable. It has an excellent balance of amino acid composition (including all 8 essential amino acids for humans) making it an excellent material for malting and brewing. Because of its small size, teff is made into whole-grain flour (bran and germ included), resulting in a very high fiber content and high nutrient content in general. Teff is useful to improve the haemoglobin level in human body and helps to prevent malaria, incidence of anaemia and diabetes. The nutrient composition of teff grain indicates that it has a good potential to be used in foods and beverages worldwide. The high levels of simple sugars and α-amino acids as a result of breakdown of starch and protein, respectively, are essential for fermentation and beer making.
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    Electrophoresis 06/2013; 34(11). DOI:10.1002/elps.201200646 · 3.03 Impact Factor
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    ABSTRACT: Varieties of a cereal may have a considerable influence on malting qualities owing to variations in the physicochemical properties of the grains. This research was aimed at assessing the influence of five teff varieties on malt quality attributes. The teff samples were malted using previously optimized malting conditions and mashed with the congress mashing procedure. In this research, the Kuncho teff variety was malted in a one year period after harvesting, whereas the other four varieties were malted after three years of storage. Alpha-and beta-amylase, and limit dextrinase activity, were in the ranges 14-68, 10-440 and 375-1072 U/kg, respectively. Extracts ranged from 54% for Dessie to 74% for Ivory teff. Free amino nitrogen, protein content, soluble nitrogen, Kolbach index, viscosity and wort colour were in the ranges 160-364mg/L, 8.6-13.6%, 532-1048mg/100 g, 24-50%, 1.441-1.629mPa s and 5.9-9.0 EBC units, respectively. High-performance liquid chromatographic analysis for individual fermentable sugars revealed that the highest value in all varieties was recorded for glucose followed by maltose. The concentration of glucose ranged from 9.49 g/L in Brown teff, to 19.42 g/L in Ivory teff, whereas maltose ranged from 2.95 g/L in Dessie teff to 16.1 g/L in Kuncho teff. All of the malt quality attributes considered in this study weremarkedly influenced (p<0.05) by the type of teff cultivar. It was concluded that the use of different teff varieties yielded malts with significantly different malt quality attributes. Copyright (C) 2013 The Institute of Brewing & Distilling
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