Effect of Grain Composition on Water Uptake by Malting Barley: A Genetic and Environmental Study

Sulphuric acid dehusked barley had a higher germinative energy and lower microbial infection than normal huskless (naked) barley, suggesting that the pericarp layer harboured microbial infection which may have limited the germination rate. Dehusking the normal huskless barley using sulphuric acid resulted in lower microbial infection, and increased germinative energy. The normal huskless barley sample had a higher b-glucan content than the acid-dehusked barley and had slower b-glucan breakdown during malting. This resulted in the release of seven times more b-glucan during mashing, and the production of wort of higher viscosity. The normal huskless barley sample had a higher total nitrogen content than the acid-dehusked barley but both samples produced similar levels of amylolytic (a-and b-amylase) activity over the same malting period. No direct correlation was found between barley total nitrogen level and the amylolytic activity of the malt. When barley loses its husk at harvest, the embryo is exposed and may be damaged. This may result in uneven germination which can reduce malting performance and hence malt quality.

Section: B +Pyger Fvieohs[r Erh I\xvegx Vigsziv]supporting

confidence: 81%

Malting Performance of Normal Huskless and Acid-Dehusked Barley Samples

Agu¹,

Devenny

Tillett³

et al. 2002

“…However the use of different cultivars (Alexis vs. Scarlett) might influence the characteristics analysed in a different way, as shown in studies of Spanish vs. Scottish barleys 2,[8][9][10]17,18 . In these, the cultivar effect was always significant, albeit of smaller size than the effect of environment.…”

Section: Epx I\xvegx Hizipstqirx Mr 7gerhmrezmer Zw -Fivmer Fevpi]wmentioning

confidence: 99%

“…The environmentally induced differences in barley and malt composition observed between samples from such contrasting regions of Northern and Southern Europe as NE Spain and E Scotland, have been analysed for different characteristics and barley genotypes 2,[8][9][10]17,18 . These studies addressed different aspects, but had a common disadvantage in attempting to analyse genotypic differences when the environmental effects were considerably greater 2,9,16 .…”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…These studies addressed different aspects, but had a common disadvantage in attempting to analyse genotypic differences when the environmental effects were considerably greater 2,9,16 . In an early study by Molina-Cano and coworkers a pair of near-isogenic barley lines were used, and the data for both genotypes showed a positive effect of the B/C hordein ratio and the water-soluble fraction of b-glucans on water uptake during steeping 9 . Additionally, the capacity of the Spanish barleys to give equivalent extracts to their Scottish counterparts, despite higher levels of protein and b-glucans, was attributed to their different hordein composition and their greater ability to produce bglucanases during germination 2 .…”

mentioning

confidence: 99%

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A Reappraisal of the Differences Between Scandinavian and Spanish Barleys: Effect of β-Glucan Content and Degradation on Malt Extract Yield in the cv.Scarlett

Molina-Cano

Romera

Aikasalo

et al. 2002

Forty one samples of the malting barley cultivar Scarlett were collected from both Scandinavia (15 from Finland and 10 from Denmark) and the Iberian Peninsula (15 from Spain and 1 from Portugal), during the harvest years of 1998 and 1999. These samples were subjected to grain analyses, comprising protein content, hordein fractions by high performance liquid chromatography (HPLC) and b-glucan content. The samples were micro-malted and the malts were analysed to determine different patterns in the influence of grain composition on malt extract development linked to the two contrasting environments. The most obvious difference found between the Scandinavian and Iberian barleys was the effect of the total and insoluble barley bglucans. They were an effective barrier of malt extract in the North, but appeared to increase extract in the South. A conclusion was that the positive effect of b-glucans in the Iberian barleys was a consequence of their greater capacity to synthesise and release b-glucan hydrolases during germination.Key words: Barley, b-glucans, malting quality. -2863(9'8-32The environmentally induced differences in barley and malt composition observed between samples from such contrasting regions of Northern and Southern Europe as NE Spain and E Scotland, have been analysed for different characteristics and barley genotypes 2,[8][9][10]17,18 . These studies addressed different aspects, but had a common disadvantage in attempting to analyse genotypic differences when the environmental effects were considerably greater 2,9,16 . In an early study by Molina-Cano and coworkers a pair of near-isogenic barley lines were used, and the data for both genotypes showed a positive effect of the B/C hordein ratio and the water-soluble fraction of b-glucans on water uptake during steeping 9 . Additionally, the capacity of the Spanish barleys to give equivalent extracts to their Scottish counterparts, despite higher levels of protein and b-glucans, was attributed to their different hordein composition and their greater ability to produce bglucanases during germination 2 .Subsequent studies focused on comparing environments, using barleys from the North and South of Europe 8 . However, when samples of the variety Alexis grown both in Scandinavia and the Iberian Peninsula were analysed, B-hordeins showed a strong negative effect along with barley protein content on the extract development of the Nordic (Scandinavian) samples 8 . In an attempt to clarify these apparently inconsistent results, we have studied the malting behaviour of the barley variety Scarlett, presently widely accepted by the brewing industry and successfully grown in many European regions. 1%8)6-%07 %2( 1)8,3(7 &EVPI] QEXIVMEPForty one samples of the malting barley variety Scarlett were collected in Scandinavia (25 samples) and the Iberian Peninsula (16 samples) in 1998 and 1999 (Table I). The Scandinavian samples were from Denmark (10 samples) and Finland (15 samples) and those of the Iberian Peninsula were from Spain (14 samples) and Portugal (1 sample)....

Mechanisms of Malt Extract Development in Barleys from Different European Regions: I. Effect of Environment and Grain Protein Content on Malt Extract Yield

Molina-Cano¹,

Rubio²,

Igartua³

et al. 2000

Malt extract yield (EXT) and barley protein content (BPROT) data from 346 EBC trials located across all the EBC countries, and composed of many different varieties, from the years 1980,1982 to 1990, inclusive, and 1993 to 1995, thus covering 13 seasons, were used to detect regional trends affecting the negative correlation between these two variables. Quadratic curves were fitted to data from each European region (North, Central, West and South), all ofwhich showed very high coefficients of determination (r2). A common trend in all regions, and also in the overall European analysis, was of EXT decreasing when BPROT increased, although the extent of decrease varied among the regions. Two different geographical pattents of variation in EXT with changes in BPROT have been observed, on the one hand those of the Iberian Peninsula and West region, and on the other, those of the North and Central regions. In the first case, the rate of decrease in EXT was almost constant across the full range of variation of BPROT, whereas, in the second case, the decrease in EXT grew progressively with increases in BPROT. Tlierefore, although "Bishop's law" on EXT decrease with BPROT increase holds true as a general statement, it would be necessary to take climatic differences into account when estimating EXT values from BPROT data.Key Words: Barlei/, malting quality, protein content. INTRODUCTION subsequent general acceptance of his findingsFollowing the classical work of Bishop in the 1930s'" worldwide. From this general acceptance, it has been barley protein content has been considered to be a always inferred that barleys from southern Europe were detrimental trait for malting quality, as it is negatively of inferior malting quality to those from humid regions, correlated with malt extract yield. It was stated, due to their generally higher protein content. There are, however, that the inverse relationship between extract however, doubts about the general validity of this negative and protein had a varietal, i.e. genetic, component, so correlation in predicting extract values from the protein a different correlation existed for each variety. It is now contents of barleys grown under very contrasting known that this negative correlation is mainly due environmental conditions. The reason is the unknown size to the hordein fraction of the proteins, not only because oi the environmental (E) and genotype x environmental of its negative correlation with starch19, the main (GE) induced variation, source of extract, but also due to its physical role as the major component of the endosperm protein matrix into Genotype x environment interaction is one of the causes which the starch granules are embedded, restricting of the unpredictable variation found in quantitative access by amylolytic enzymes during germination12.characters of cultivated plants (see review in reference 16) such as malting quality traits (see reviews in 7,9).Bishop worked out his equations from data obtained studies on GE of malting quality parameters conducted on barl...