The impact of genotype and environmental conditions on malt quality parameters of winter barley (Hordeum vulgare L.)

Ječam namijenjen za slađenje mora udovoljiti posebnim zahtjevima koje postavlja industrija piva. Sladarsku kakvoću uvjetuje genotip, iako značajan utjecaj imaju i okolišni uvjeti kao što su tip tla te fluktuacije u temperaturi i padalinama tijekom uzgoja. Cilj je ovog istraživanja bio na temelju odabranih ozimih kultivara ječma uzgojenih na različitim agroekološkim područjima ispitati utjecaj genotipa i okolišnih uvjeta na sladarsku kakvoću. U istraživanju su korištena tri kultivara ozimog ječma, a pokus je postavljen na četiri lokacije (tla različite plodnosti) tijekom tri vegetacijske godine. U radu je određena kakvoća zrna ječma koji je mikroslađenjem preveden u slad. Laboratorijskim ispitivanjima određena je kakvoća slada koja je obuhvatila parametre koji opisuju citolitičku, amilolitičku i proteolitičku razgrađenost slada. Primjenom visokotlačne tekućinske kromatografije obrnutih faza (RP-HPLC) određena je hordeinska frakcija skladišnih bjelančevina u zrnu ječma i u dobivenom sladu u svrhu određivanja njihove razgrađenosti tijekom slađenja. Na temelju dobivenih rezultata za količinu ekstrakta, značajnog parametra u ocjeni slada, između ispitivanih kultivara nije utvrđena statistički opravdana razlika, ali je postojala značajna razlika između ispitivanih godina i lokacija. Statistička značajnost razlika u prosječnim vrijednostima količine bjelančevina u zrnu ječma ukazuje na klimatsku varijabilnost istraživanih vegetacijskih razdoblja te na veliki utjecaj genotipa i okolišnih uvjeta na formiranje udjela bjelančevina u zrnu. Količina β-glukana u sladu ukazuje na značajnost razlika između kultivara, kao i na utjecaj godine i lokacije na ispitivano svojstvo. Prema prosječnim vrijednostima, kultivar Vanessa pokazao je značajnije veću aktivnost u pogledu citolitičke, amilolitičke i proteolitičke razgrađenosti u odnosu na kultivare Zlatko i Barun, iako je u prosjeku imao veći udio bjelančevina u zrnu. Korelacijska analiza pokazala je da je većina parametara sladarske kakvoće visoko međusobno povezana bilo u pozitivnom i ili u negativnom smjeru. Ekstrakt slada značajno negativno korelira s količinom hordeina u zrnu ječma i količinom β-glukana. Promatrajući utjecaj pojedinih hordeinskih skupina, uočljiv je izrazito jak negativan utjecaj B skupine hordeina na ekstrakt slada. Procjena stupnja razgrađenosti hordeina tijekom slađenja u velikoj mjeri odražava promjene koje se događaju s bjelančevinama zrna ječma tijekom slađenja te jasno pokazuje razlike između kultivara vezano uz razgrađenost bjelančevina. Provedbom pokusa i proučavanjem značajnosti utjecaja okolišnih uvjeta na kakvoću zrna i slada dobiveni su vrijedni podaci o učinku genotipa u datim okolnostima koji će se moći koristiti pri procjeni stabilnosti parametara sladarske kakvoće u selekciji genotipova pogodnih za naše uzgojno područje.Barley aimed for malt production must meet a special requirements proposed by brewing industry. Malting quality is controlled by genotype, although environmental conditions like temperature and precipitation fluctuations have also significant influence on malt quality. The aim of this study was to explore the impact of genotype and environmental conditions, based on selection of winter cultivars grown at different agroecological environments, on malting quality. This study included three winter type barley cultivars and field trials were conducted at four different locations (different soil fertility) during three vegetation years. Prior to micromalting barley grain quality was determined. Quality of malt was determined by laboratory analysis of parameters of cytolytic, amilolytic and proteolytic degradation of malt. Reversed-phase high-performance liquid chromatography analysis was applied for determination of endosperm hordein fractions in barley grain and in malt, with aim to determine the hordein degradation during malting. Based on obtained results for malt extract content, which is important parameter in malt evaluation, there was no evidence that would point out the statistically significant difference between years and locations included in this study. Statistically significant difference among average values of barley grain protein content points to the climate variability of investigated vegetation periods and to the great impact of genotype and environmental conditions on a barley grain protein formation. The results of β-glucan content in malt showed significant difference between cultivars. Significant impact of year and location on this parameter was also noticed. According to average values, cultivar Vanessa showed significantly higher activity of enzymes in terms of cytolytic, amilolytic and proteolytic degradation of the endosperm when compared to cultivars Zlatko and Barun, in spite of higher average grain protein content. The results of the analysis of linear correlation carried out on the particular malt quality data obtained showed high coherence either in positive or negative direction. Malt extract content significantly negatively correlates with barley grain protein content and β-glucan content. Observing the impact of the individual hordein groups, the significantly negative impact of the B hordein on malt extract content was noticed. One of the important physical-chemical changes that occur during malting is degradation of the hordein proteins and conversion to soluble paptides and amino acids. Assessment of the rate of hordein degradation clearly indicates differences among cultivars in term of protein degradation. Implementation of the field trial and study on the impact of the environmental conditions on barley grain and malt quality gives valuable data on genotype effect in given circumstances that will be used for malt quality parameters stability estimation in selection of genotypes of favorable breeding value

Malting quality indicators of Croatian dual-purpose barley varieties

Malting barley varieties usually demand higher expences than feed varieties, at least as far as management practice is concerned. For this reason, many growers in Croatia search for a quality replacement of malting varieties. Croatian market allows dual-purpose varieties, but strict quality parameters have to be met in order for a variety to be recognized as a malting/feed variety. The aim of this research was to preliminary assess the malting quality of several malting, feed and multipurpose (dual or combined) malting/feed barley varieties. 11 barley varieties were grown in Osijek area during 2011: seven malting/feed (M/F), two malting (M) and two feed barley varieties (F). The suitability for the beer production was assessed according to the malting quality indicators, determined by using standard methods of analytica EBC (European Brewing Convention). As expected, both malting varieties (Vanessa and Tiffany) demonstrated the best malting quality parameters. Most of the combined malting/feed varieties were within recommended values, except Maxim, Lukas and Gazda, which showed the lowest results in friability. Considering that the results were collected and evaluated over a period of one year, this study was taken as a good pointer to future, longer lasting investigations

POVEZANOST RAČUNALNE ANALIZE SLIKE S JAČINOM GLUTENA PŠENICE

The objective of this study was to determine bread slice medium part properties in relation to quality parameters with a focus on gluten strength. Since sensory evaluation of bread is time consuming, expensive and subjective in nature, computerized image analysis was applied as objective method of bread crumb quality evaluation. Gluten Index method was applied as fast and reliable tool for defining gluten strength of wheat. Significant (P90) Ana, Demetra, Klara, Srpanjka and Divana have shown trend to give unequal and bigger crumb grains while cultivars Golubica, Barbara, Žitarka, Kata and Sana with optimal gluten strength (GI= 60-90) have shown finer and uniform crumb grain.Cilj istraživanja bio je utvrditi povezanost parametara izgleda sredine kruha i kakvoće pšenice, s naglaskom na jačinu glutena. Budući da je senzorska procjena kruha vremenski zahtjevna, skupa i relativno subjektivna, u procjeni izgleda sredine kruha korištena je računalna analiza slike kao objektivna metoda. Jačina glutena pšenice određena je brzom i pouzdanom gluten indeks metodom. Statistički značajna (p90), Anu, Demetru, Klaru, Srpanjku i Divanu, karakterizira neujednačena poroznost sredine kruha s velikim šupljinama, za razliku od kultivara Golubice, Barbare, Žitarke, Kate i Sane s optimalnom vrijednošću gluten indeksa (GI= 60-90), čija je poroznost, s obzirom na manje šupljine, bila ujednačenija

The Relation between Dough Rheology and Bread Crumb Properties in Winter Wheat

The present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. The rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. The image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and efficient measurement of bread characteristics. The highest significant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka’ and ‘Golubica’ have shown finer and uniform bread crumbs with regard to optimal dough physicochemical characteristics

The Relation between Dough Rheology and Bread Crumb Properties in Winter Wheat

The present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. The rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. The image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and efficient measurement of bread characteristics. The highest significant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka’ and ‘Golubica’ have shown finer and uniform bread crumbs with regard to optimal dough physicochemical characteristics

Quality of wheat cultivars created at the Agricultural Institute Osijek in relation to high molecular weight glutenin subunits (HMW – GS) composition

Abstract Background and Purpose: The objective of this study was to estimate the effect of high molecularweight glutenin subunits(HMW-GS) composition of the Glu-1 loci on the quality of winter wheat cultivars created at the Agricultural Institute Osijek. Materials and Methods: Ten winter wheat cultivars were grown in 4 different locations during two years in a randomized complete block (RCB) experimental design with three repetitions at each location. Samples were collected and subjected to quality analysis and determination of HMW-GS composition by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results: Considering theHMW-GS composition, the most frequent subunit at the Glu-A1 locus was N, at the Glu-B1 locus 7+9 and at the Glu-D1 locus 2+12. The analyzed cultivar Demetra, with subunits 5+10 at the Glu-D1 locus, has shown the best bread-making quality. Among cultivars with subunits 2+12 at the Glu-D1 locus, the cultivars with subunits 7+8 at the Glu-B1 locus have shown on average better characteristics of gluten strength with regard to higher values of Gluten Index and resistance to exstensibility ratio (R/Ext). The results of the linear correlation between quality parameters and HMW-GS composition, expressed as the Glu-1 score, have shown the most significant (P<0.05) influence ofHMW- -GS on Gluten Index r=0.42), dough energy (r=0.48) and dough maximum resistance (r=0.47). Conclusions: These results indicated that the presence of HMW-GS 5+10 and 7+8 contributes to higher bread-making quality of analyzed cultivars. TheHMW-GS composition has predictive value in quality analysis, therefore, the composition ofHMW-GS at the Glu-1 loci has to be taken into consideration when parents for a bread wheat breeding programme are chosen

Agronomic and Quality Traits of Winter Barley Varieties (Hordeum vulgare L.) under Growing Conditions in Croatia

This paper presents an investigation of the agronomic and quality traits of the barley varieties, their stability and adaptability and specific reactions towards growing conditions in the Republic of Croatia. During four year trials on localities in Tovarnik, Nova Gradiska, Pozega and Osijek we researched 14 winter barley varieties. Interaction effect variety*environment has been explored together with estimation of significant parameters of stability towards grain yield, hectoliter weight, protein and starch content. With usage of cluster analysis it was possible to group varieties considering genotype x environment interaction (GEI). Impact of year, location and variety on grain yield, hectoliter grain weight, protein and starch content has been estimated by analysis of variance. There was no significant difference between two different sowing rates (300 and 450 grains/ m2) for grain yield, hectoliter weight and protein content. There also was no significant interaction of variety*sowing rate for all researched parameters. Parameters of stability and achieved grain yield show that under favorable growing conditions one can expect better results of varieties ‘Trenk’ and ‘Princ’ with lower stability and variety Barun with higher stability of grain yield. Stability parameters point out varieties ‘Vanessa’, ‘Plaisant’, ‘Favorit’ and ‘Zlatko’ to have auspicious reaction to grain yield under extensive cultivation conditions but with significantly different levels of grain yield achieved. Cluster analysis for grain yield of the highest clustering similarity level displays five variety groups and variety Princ that does not show tendency to group with none of the other varieties. The first group is made by varieties ‘Barun’, ‘Zlatko’ and ‘Rex’. The second one consists of varieties ‘Prometej’ and ‘Gvozd’ with ‘Bingo’ and ‘Sladoran’. ‘Tiffany’ and ‘Vanessa’ make special, somewhat detached group of varieties that tend to group together with varieties ‘Favorit’, ‘Trenk’, ‘Plaisant’ and ‘Lord’ but on the lower grouping level

UTJECAJ GENOTIPA NA OMJER VLAŽNOG GLUTENA I UKUPNIH BJELANČEVINA ZRNA PŠENICE

Gluten proteins are primarily responsible for the end-use wheat quality and quite a number of methods for gluten quality evaluation was suggested and applied. The aim of the work presented here was to examine the genotype effect on the ratio of wet gluten to total protein content (WG/P), as measure of wet gluten production per protein unit. Ten winter wheat cultivars of Agricultural Institute Osijek were included in this study. Signifi cant (P<0.05) difference in WG/P ratio was noticed among analyzed cultivars. The ratio of the wet gluten to protein content varied within a broad range depending on genotype. The data showed that, with regard to Gluten Index (GI) value, cultivars with WG/P ratio range from 2.7 to 3.0 had optimal baking characteristics of gluten (GI varied between 75 and 90), while cultivars with strong gluten characteristics (GI>90), known as improvers, had WG/P ratio between 2.3 and 2.4. Signifi cant (P<0.05) negative correlation (r=-0.622) was determined between GI and WG/P ratio.Bjelančevine glutena imaju ključan utjecaj na kakvoću pšenice i preradbenu vrijednost brašna. Cilj rada bio je ispitati u kojoj mjeri je omjer vlažnog glutena i ukupnih bjelančevina (WG/P), kao mjera dobivene količine glutena po jedinici ukupnih bjelančevina, karakteristika genotipa. U radu je analizirano 10 kultivara ozime pšenice Poljoprivrednog instituta Osijek. Kultivari se značajno razlikuju (p<0,05) po vrijednostima omjera WG/P. Kultivari S. Žitarka, Barbara, Žitarka i Golubica s omjerom WG/P između 2,7 i 3,0 pokazali su optimalna tehnološka svojstva. Gluten indeks ovih kultivara kreatao se od 75 do 90, dok su kultivari Srpanjka, Ana i Demetra, inače poznati kao poboljšivači obzirom na vrijednost GI>90, imali omjer WG/P između 2,3 i 2,4. Statistički značajna (p<0,05) negativna korelacija (r=-0,622) utvrđena je između GI i omjera WG/P

ZNAČAJ VISOKOMOLEKULARNIH PODJEDINICA GLUTENINA U PROCJENI KAKVOĆE PŠENICE

High-molecular-weight glutenin subunits (HMW-GS) composition was analyzed by sodium-dodecyl-sulfat-polyacrilamid-gel electrophoresis (SDS-PAGE), while the quantitative determination of total HMW-GS was obtained by reversed phase- high performance liquid chromatography (RP-HPLC). Considering HMW-GS composition, the most frequent subunits at Glu-A1 locus were N, at Glu-B1 locus 7+9 and at Glu-D1 locus 2+12. The cultivars with the GS 5+10 at Glu-D1 locus have shown better technological characteristics in contrast to cultivars with the GS 2+12. The cultivars Žitarka, Srpanjka, Barbara, Klara and Golubica in spite of presence HMW-GS 2+12 have shown very good and good technological properties because they had optimal proportions (>10%) of total HMW-GS. The results of the linear correlation analysis between quality parameters and HMW-GS composition have shown significant (P10%) ukupnih HMW-GS. Rezultati linearne korelacije između parametara kakvoće i sastava HMW-GS pokazali su značajan (p<0,05) pozitivan utjecaj HMW-GS (Glu-1 bodovi) na sedimentacijsku vrijednost (r=0,55), gluten indeks (r=0,72), energiju tijesta (r=0,61), maksimalni otpor (r=0,64), te omjera otpora i rastezljivosti tijesta (r=0,58). U odnosu na sastav HMW-GS, njihovi udjeli pokazuju značajniji utjecaj na udio proteina (r=0,82), vrijeme razvoja tijesta (r=0,70), stupanj omekšanja (r=-0,90), energiju tijesta (r=0,74) i na volumen kruha (r=0,65)

DETERMINATION OF WHEAT STORAGE PROTEINS BY RP-HPLC METHOD

Rezervne bjelančevine zrna pšenice u značajnoj mjeri utječu na funkcionalna svojstva brašna. Cilj istraživanja bio je kvalitativno i kvantitativno analizirati rezervne bjelančevine pšenice primjenom visokotlačne tekućinske kromatografije obrnutih faza (RP-HPLC). U radu je ispitano 13 kultivara ozimih pšenica uzgojenih na Poljoprivrednom institutu Osijek. Albumini i globulini su, s prosječnom vrijednošću od 19,03%, najmanje zastupljeni u ukupnim bjelančevinama zrna ispitivanih kultivara pšenice. Analizom kromatograma albumina i globulina, utvrđeno je da se profili ispitivanih kultivara razlikuju po broju podjedinica (19-22), s konstantnim vremenom zadržavanja od 7 do 15 min. Unutar glijadinske skupine bjelančevina, dominirali su hidrofobni - (8-10 podjedinica) i - glijadini (6-9 podjedinica), dok se broj podjedinica hidrofilnih 5- kretao od 1 do 3, a 1,2- od 3 do 6. Prema dobivenim rezultatima, - i - glijadini su dominantne komponente glijadinske skupine u odnosu na minorne 5- i 1,2- glijadine. Unutar gluteninske skupine bjelančevina, LMW podjedinice prisutne su s najvećim brojem podjedinica (16-19), dok se broj podjedinica HMW glutenina kretao od 4 do 6, što znači da su LMW podjedinice dominirale unutar gluteninske skupine. Prosječan udio glutena iznosio je 80,97 %. Glijadini su, s prosječnom vrijednošću od 44,20%, u ukupnim bjelančevinama zrna dominantnija skupina u glutena, u odnosu na glutenine čiji je prosječni udio iznosio 36,77 %.The wheat storage proteins have the most important role in defining functional properties of flour. The aim of this study was to analyse the wheat storage proteins profiles and relative amount by reversed phase-high performance liquid chromatography (RP-HPLC). 13 wheat cultivars grown at Agricultural Institute Osijek were investigated. As compared to the other wheat storage protein fractions the average proportion of albumins and globulins was the least (19.03%). The albumins and globulins chromatogram profiles were different regarding subunits number (19-22) with constant retention time from 7 to 15 minutes. Within gliadins group hidrophobic - (8-10 subunits) and - gliadins (6-9 subunits) were dominant, while the subunits number of hydrophilic gliadins varied from 1 to 3 for 5- and 3 to 6 for 1,2- gliadins. According to obtained results - and - gliadins were dominant components of gliadins group in relation to minor 5- and 1,2- gliadins. The LMW glutenins with 16 to 19 subunits were dominant proteins of glutenins group compared with the HMW glutenins whose subunits number varied from 4 to 6. The average proportion of gluten was 80.97%. Concerning gluten proteins, the gliadins were dominant group (44.20%) compared with the average glutenins proportion (36.77%)