The Influence of Wheat Malt Quality on Final Attenuation Limit of Wort

This paper aimed to investigate the influence of certain wheat and wheat malt quality indicators on limit of attenuation of wort (LAT). The experiment was conducted using wheats that have been proven to display the best malting properties with heightened total and soluble N and very good viscosity. Standard micromalting and brewing processes and analysis were applied. The obtained results showed that the quality of analyzed malts was satisfying. Statistical analysis determined no significant correlation between the limit of attenuation of wort and any of the other analyzed quality indicators. The lack of close correlations between indicators is probably due to the extremely complex intertwine of factors influencing the LAT, pointing to the fact that this particular indicator should be observed as separate and mainly variety-dependent

Domestic hulless barley and malt as an easily available source of β-glucan

β-Glucans are described as non-starch polysaccharides, characterized by (1→3), (1→4) β-D-glucose linkage. In human nutrition, they are regarded as extremely wanted because of their bioactive and medicinal properties. Since β-glucans comprise soluble fibres that have the ability to lower cholesterol, regulate blood sugar, reduce the risk of heart disease and colon cancer. Especially desirable are (1,3)-β-D-glucans because they act as immunomodulatory agents. The aim of this paper was to determine the mass fraction of β-glucans and the ratio of total and soluble β-glucans in barley and malt in domestic hulless barley varieties. Hulless barley is an accesible and cheap source of β-glucans. Four different domestic varieties of hulless barley obtained from the Agricultural Institute Osijek were examined. The results indicate that all tested varieties have higher β-glucans content than standard winter and spring varietes. Variety Matko showed close relation to the EFSA (European Food Safety Authority) recommendations of 750 mg of soluble β-glucans per serving

Toxicity of Fusarium Toxins

Plijesni roda Fusarium jedni su od najčešćih kontaminanata žitarica u poljoprivrednoj proizvodnji u agroekološkim uvjetima Republike Hrvatske. Fusarium sp. metaboliziraju sekundarne toksične metabolite-mikotoksine koji mogu uzrokovati akutna i kronično toksična djelovanja na ljude i životinje. Kontaminacija usjeva Fusarium vrstama može nastati prije žetve (na polju), ali i poslije žetve (u skladištima i silosima). Posljedično tome evidentna je i kontaminacija žitarica i uskladištenih proizvoda Fusarium toksinimaFusarium fungi are among the most common contaminant of cereals in agricultural production in agroecological conditions of the Republic of Croatia. Fusarium sp. metabolize toxic secondary metabolites-mycotoxins that can cause acute and chronic toxic effects on humans and animals. Fusarium contamination of crop species can occur before harvest (the fi eld), and after harvest (in warehouses and silos). Consequently, contamination of crops and stored products with Fusarium toxins is evident

The Effect of Barley and Wheat Microflora on Malt and Beer Quality

Mikroorganizmi (plijesni, kvasci i bakterije) koji se u velikom broju pojavljuju na ječmu i pšenici, sirovinama za proizvodnju slada, imaju značajan utjecaj na pokazatelje kakvoće konačnog proizvoda, slada. Posljedično, utječu i na kakvoću sladovine, odnosno piva. Iako su bakterije i kvasci dominantne vrste na ječmu i pšenici prije i nakon žetve, pravi problem predstavljaju plijesni zbog štetnih metabolita, koji utječu kako na zdravstvenu ispravnost sirovine, tako i na kakvoću samog slada. Plijesni od posebnog značaju pripadaju rodu Fusarium i nanose ekonomsku štetu cjelokupnoj industriji žitarica, te predstavljaju zdravstvenu prijetnju zdravlju ljudi i životinja zbog mikotoksina koje proizvode. Zbog svega navedenog, nužno je praćenje mikrofl ore tijekom cijelog proizvodnog lanca „ječam-pivo“ i suzbijanje proliferacije nepoželjnih mikroorganizama prije i tijekom slađenja.Microorganisms (fungi, yeasts and bacteria) largely present on barley and wheat, raw materials used for malt production, have great effect on the final product, malt. Consequently, microorganisms also affect the quality of wort and beer. Although bacteria and yeasts are dominant species on barley and wheat before and after the harvest, the real problem are fungi, due to their harmful metabolites that affect health safety of raw material and the quality of malt itself. Particularly problematic fungi are those from genus Fusarium that infl ict economical damage to the whole cereal industry, and due to the possibility of the mycotoxins production, they present health threat to humans and animals. It is therefore necessary to monitor microfl ora throughout the productive chain „barley-beer“ and to suppress the proliferation of unwanted microorganisms, before and during malting

Survey of β-glucans in domestic barley's varieties

β-glucans in cereals are desirable, but malting and brewing industries appreciate lower levels of these compounds because high level of β-glucans in barley varieties can cause unsatisfactory degradation of cell walls during malting. Low to moderate β-glucan content in barley is preferable for malt production. The aim of this study was to investigate the share of β-glucans in 16 Croatian barley varieties at three representative locations in eastern Croatia: Osijek, Slavonski Brod and Tovarnik over three consecutive seasons (2012-2014). Total β-glucan content in barley samples was determined using enzymatic method. Overall, total β-glucan contents ranged between 2.21 and 4.50 g/100 g dry weight, where barley feed variety had the highest and malting barley variety had the lowest content. Most of the investigated barley varieties had total β-glucan content lower or significantly lower than 4 %. Barley varieties used for livestock (feed and hulless varieties) appear to have the highest (feed > 4.4, hulless 4.6 > g/100 g), and brewing varieties have the lowest β-glucan (< 3.6 g/100 g)

Development of enzyme potential in different purpose barley varieties during malting

Razvoj enzimske aktivnosti zrna ječma tijekom procesa slađenja je jedno od ključnih zbivanja kojom se osigurava zadovoljavajuća tehnološka kvaliteta slada. Brojna istraživanja su provedena na ovu temu kojima je ustanovljeno da se najbolji rezultati vezani za razvoj enzimskog potencijala zrna osiguravaju slađenjem namjenskih, jarih, dvoredih pivarskih sorti uz odgovarajući režim slađenja kojim se osiguravaju procesni uvjeti koji pogoduju aktiviranju već u zrnu prisutnih i/ili de novo sintezi enzima. Cilj ovog istraživanja bilo je ustanoviti kako s obzirom na gore postavljene zahtjeve reagiraju različite namjenske, dvorede, jare i ozime sorte ječma koje se uobičajeno koriste za proizvodnju slada u Hrvatskoj. Temeljem dobivenih rezultata ustanovljeno je aktivnost α-amilaze u svim ispitivanim sortama bila je unutar, dok je aktivnost β-amilaze u sve tri sorte bila je viša od standardnih vrjednosti za svijetli slad. Oba enzima su pokazala najvišu aktivnost zadnjeg, četvrtog dana klijanja. Proces sušenja slada značajno više smanjuje aktivnost β-amilaze (25-30%) nego α-amilaze (oko 10%). Utvrđivani su i ostali pokazatelji kvalitete polaznih ječmova, procesa mikroslađenja i gotovih sladova. Ustanovljeno je da sve tri sorte daju svijetli pivarski slad vrlo dobre kvalitete. Neki pokazatelji kvalitete slada poput topljivog dušika u sladovini i viskoznosti su imali izvrsne vrijednosti, najproblematičniji pokazatelj je bila fiabilnost. Međutim, kako je friabilnost kumulativni pokazetelj na koji utječu brojni pojedinačni faktori ovo zahtijeva dodatna istraživanja.The development of enzymatic activity of barley grains during the malting process is one of the key developments which ensures satisfactory technological quality of malt. Numerous studies have been conducted on this topic, which found that the best results related to the development of enzymatic potential of grain are a result of malting purpose, spring, two-row brewing varieties. The application of appropriate malting regime that ensures process conditions favaurable for te activation of already present in the grain and/or de novo synthesis enzymes are also an important factor. The aim of this research was to establish how different purpose, two - row, spring and winter varieties of barley, which are commonly used for malt production in Croatia, react to the above requirements. Based on the obtained results, the α-amylase activity in all examined cultivars was found to be within the standard values, while the β-amylase activity in all three cultivars was higher than the standard values for light malt. Both enzymes showed the highest activity on the last, fourth day of germination. The malt drying process significantly reduced β-amylase activity (25- 30%), in comparison to the activity of α-amylase (about 10%). Other indicators of the quality of starting barley, micromalting process and finished malts were also determined. It was found that all three varieties give light malt approprite for malting, reulting with malt of very good quality. Some malt quality indicators such as soluble nitrogen in wort and viscosity had excellent values, and the most problematic indicator was fiability. However, as friability is a cumulative indicator affected by a number of individual factors this requires further research

Essential oils – inhibitors of fungal growth and mycotoxin synthesis

Prirodne antimikrobne tvari u očima potrošača postaju sve poželjnije jer su manje toksične, stoga je trenutno vrlo popularno istraživanje eteričnih ulja kao zamjene za kemijske fungicide. Eterična ulja ili pojedini njihovi sastojci posjeduju, između ostalih, antifungalna i antimikotoksikogena svojstva. Ova osobina je posebice izražena kod eteričnih ulja fenolne strukture, a stanična membrana je glavno mjesto njihovog djelovanja. Njihova djelotvornost ovisiti će o abiotskim i biotskim interakcijama u okolišu.Naturally occurring antimicrobals are becoming more and more desirable mainly because they are less toxic for humans. Therefore, researches that are trying to substitute fungicides with essential oils are very popular. Essential oils or their components show antifungal and antimycotoxinogenic properties. Antifungal activity was especially observed in essential oils rich in phenolic compounds while the cell membrane is the main site of their action. The effectiveness of essential oils depends on abiotic and biotic environmental conditions

Craft brewing – is it really about the sensory revolution?

The sudden craft breweries expansion currently occurring in Europe, and by that also in Croatia, has been a true conundrum. The question is why craft breweries currently undergo such intense propagation. The answers to this is not simple and has to be monitored from a few different angles: what are today’s consumer’s preferences? Why this sudden need to drink posh beer? Health wise – is it healthier to drink craft beer than industrial? The fact is that craft breweries offer beer with a story. The popularity of health benefits of moderate beer consumption, different reports in popular papers and magazines on polyphenolic and other anti-oxidative compounds that aid catching free radicals and reduce the damage they cause, contribute to the shift from industrial plane lager beer craft beer. In the eye of the scientific storm-genetic manipulation with yeast strains, and barley cultivars, water treatments, automatization, people choose simple procedures and raw materials that give them a feeling of uniqueness. This paper contributes to the knowledge of why craft breweries are taking on more and more popularity and why are consumers attracted to such products

Uzroci, posljedice i prevencija prekomjerna pjenjenja piva

Prekomjerno pjenjenje piva (engl. beer gushing) definira se kao naglo i nekontrolirano pjenjenje piva odmah po otvaranju ambalaže, bez prethodnog izlaganja ambalaže trešnji ili visokoj temperaturi. Ta je pojava uzrok velikim gubitcima u sladarama i pivovarama širom svijeta te se smatra iznimno nepoželjnom. Razlikujemo primarno i sekundarno prekomjerno pjenjenje piva. Fungalne kontaminacije ječma, posebno kontaminacija plijesnima roda Fusarium, izravno se povezuju s pojavom primarnog prekomjernog pjenjenja piva. Ove plijesni sintetiziraju male proteine nazvane hidrofobini, koji se navode kao glavni uzročnici prekomjernog pjenjenja piva. Uzročnici sekundarnog prekomjernog pjenjenja piva su brojniji i uključuju različite kemikalije i postupke koji se upotrebljavaju tijekom proizvodnje piva. Sekundarno pjenjenje piva uglavnom se može izbjeći primjenom dobre proizvođačke prakse, dok je problem učinkovitog suzbijanja primarnog prekomjernog pjenjenja piva još uvijek predmet brojnih istraživanja

Upotreba prediktivnih modela za analizu rasta Bifidobacterium animalis subsp. lactis Bb-12 u kravljem, kozjem i sojinom mlijeku

The aim of this study was to use a predictive model to analyse the growth of a probiotic strain Bifidobacterium animalis subsp. lactis Bb-12 in cow’s, goat’s and soy milk. The Gompertz model was used, and the suitability of the model was estimated by the Schnute algorithm. Except for the analysis of Bifidobacterium animalis subsp. lactis Bb-12 growth, the Gompertz model was also used for the analysis of pH changes during the fermentation process. Experimental results, as well as the values of kinetic parameters obtained in this study, showed that the highest growth rate of Bifidobacterium animalis subsp. lactis Bb-12 was obtained in goat’s milk, and the lowest in soy milk. Contrary to the growth of Bifidobacterium animalis subsp. lactis Bb-12, pH decreased faster in soy milk than in cow’s milk. The highest rate of pH decrease was also observed in goat’s milk, which is in correspondence with results of various previous studies. The Gompertz model proved to be highly suitable for analysing the course and the fermentation kinetics in these three kinds of milk, and might be used to analyse the growth kinetics of other probiotic and starter cultures in milk.Cilj rada bio je upotrijebiti jedan od prediktivnih modela rasta bakterija za analizu rasta probiotičkog soja Bifidobacterium animalis subsp. lactis Bb-12 u kravljem, kozjem i sojinom mlijeku. Korišten je Gompertzov model, a prikladnost modela je procijenjena Schnuteovim algoritmom. Osim za analizu rasta Bifidobacterium animalis subsp. lactis Bb-12, Gompertzov model korišten je i za analizu kretanja pH vrijednosti tijekom fermentacije. Eksperimentalni rezultati, kao i vrijednosti kinetičkih parametara, dobiveni u ovom radu, pokazali su da je najveća brzina rasta Bifidobacterium animalis subsp. lactis Bb-12 bila u kozjem mlijeku, a najmanja u sojinom mlijeku. Suprotno u odnosu na rast Bifidobacterium animalis subsp. lactis Bb-12, pH vrijednost opadala je brže u sojinom mlijeku nego u kravljem. Najveći pad pH bio je također u kozjem mlijeku, što potvrđuju rezultati naših prethodnih studija kao i rezultati drugih autora. Gompertzov model pokazao se pogodnim za analizu tijeka i kinetike fermentacije u ove tri vrste mlijeka i može se koristiti za analizu kinetike rasta drugih probiotičkih i starter kultura u mlijeku