An application of classical and instrumental methods of analysis in quality control of beer

Abstract

In order to control the quality of beer and raw materials for production of beer in Belgrade Beer Industry (BIP), water is analyzed (city, technological and demineralized water). Measurements of pH values indicated the increased pH values in the sample of technological water, which had no impact on wort hopping, since the tested samples of wort, young beer and final product had a pH value within the expected range. After processing city water, a sample of technological water was found with increased carbonate hardness, which is caused by the increased content of sodium hydrogen carbonate. Analysing the titration alkalinity, titration acidity and buffering power, it was found that the alkalinity was decreasing which is in accordance with the determination of pH values of wort and beer samples (young beer and final product). Analyzing the content of anions and cations in the examined water samples, it has been shown that the concentration of these examinated anions (Cl-, NO3-, SO42- and PO43-) and cations (NH4+, Na+, K+, Ca2+, Mg2+) are within the limits prescribed by the Regulations on hygienic safety of drinking water, and thus by the Regulations of quality and other requirements for beer. The contents of anions in wort and beer samples (young beer and final product) were determined by ion chromatography method. The contents of sulphate and nitrate ions were within the recommended limits. The concentration of chloride ions was above 150 mg/dm3, which may have an impact on the sensory properties of beer, while changes in the content of phosphate ions were insignificant.

U cilju kontrole kvaliteta piva i sirovina za proizvodnju piva u Beogradskoj industriji piva (BIP) analizirana je voda (gradska, tehnološka i demineralizovana). Merenja pH vrednosti ukazala su na povećanu vrednost pH u uzorku tehnološke vode, ali to nije imalo uticaja na ukomljavanje slada pošto su ispitivani uzorci sladovine, kao i uzorci mladog piva i gotovog proizvoda imali vrednost pH u očekivanom opsegu. Obradom gradske vode dobio se uzorak tehnološke vode sa povećanom karbonatnom tvrdoćom, koja je prouzrokovana povećanim sadržajem natrijum-hidrogenkarbonata. Analizom titracionog alkaliteta, titracionog aciditeta, i moći puferovanja, utvrđeno je da se alkalitet smanjuje što je u saglasnosti i sa određivanjem pH vrednosti uzoraka sladovine i piva (mladog i gotovog proizvoda). Analiza sadržaja anjona i katjona u ispitivanim uzorcima vode, pokazala je da je koncentracija ispitivanih anjona (Cl-, NO3-, SO42- i PO43-) i katjona (NH4+, Na+, K+, Ca2+, Mg2+) u granicama propisanim Pravilnikom o higijenskoj ispravnosti vode za piće, a time i sa Pravilnikom o kvalitetu i drugim zahtevima za pivo. Sadržaj anjona u uzorcima sladovine i piva (mladog i gotovog proizvoda) određen je metodom jonske hromatografije. Sadržaj sulfat- i nitrat-jona je bio u preporučenim granicama. Koncentracija hlorid-jona je bila iznad 150 mg/dm3, što može imati uticaja na senzorne karakteristike piva, dok je promena sadržaja fosfat-jona bila neznatna.