Microbiological Contaminants in the Production of Malt and Beer

Pivo je pjenušavo osvježavajuće piće s malom koncentracijom alkohola i karakterističnom aromom po hmelju, dobiveno vrenjem pivske sladovine pomoću specijalnih sojeva pivskoga kvasca roda Saccharomyces. Slad se dobiva preradom ječma, neslađenih žitarica i hmelja. Pri proizvodnji slada susrećemo različitu mikrofloru koju čine bakterije, kvasci i filamentozne gljive. Sam sastav mikroflore određen je klimatskim uvjetima tijekom uzgoja žitarica, mjerama uzgoja, uvjetima skladištenja i transporta te procesnim uvjetima tijekom proizvodnje slada. Najveći problem u sladarstvu i pivarstvu predstavljaju plijesni koje mogu proizvoditi štetne metabolite koji utječu na zdravstvenu ispravnost i kakvoću slada. Pri tome su najznačajnije plijesni roda Fusarium koje proizvode mikotoksine skupina trihotecena (B nivalenol, deoksinivalenol i T-2 toksin) i zearalenona. Zbog nemogućnosti isključivanja zaraženih zrna žitarica tijekom proizvodnje potrebno je praćenje cijelog proizvodnog lanca „ječam-pivo“ kako bi se osigurala zdravstvena ispravnost i kvaliteta gotovog proizvoda.Beer is a foamy refreshing drink with a small concentration of alcohol and a characteristic aroma of hops. Beer is produced by fermentation of malted barley or malted wheat using different species of brewer's yeast – Saccharomyces sp. Malt is produced from barley, cereals and hops and during its production different bacteria, yeasts and moulds are present. The composition of the microbial population is determined by climate conditions during cereal growth, by cereal growth methods, by the conditions during storage and transportation, and conditions during malt production. Moulds that can produce mycotoxins represent the biggest concern because mycotoxins can negatively effect the safety and quality of malt. Various species of Fusarium are the most significant producers of mycotoxins during beer and malt production. They produce mycotoxins from the trichothecene (B nivalenol, deoxynivalenol and T-2 toxin) and zearalenone groups. Since infected cereal grains cannot be completely removed during production, complete monitoring of the production chain from barley to beer is needed to ensure the safety and quality of the final product