An innovative method for the study and control of microorganisms in beer has been developed by Bulgarian scientists from the Center for Food Biology (CBH) with the assistance of the Union of Brewers (SPB). The molecular biological method for the microbiological purity of beer has no analogue in Europe and is based on the popular real-time polymerase chain reaction - qPCR. The original procedure developed for the quantitative measurement of bacterial DNA in beer is more accurate, faster and more precise than the classical methods for testing the microorganisms in beer.
"The new method is the result of a series of studies that lasted two years in collaboration between the Center for Food Biology and the Brewers' Union. Our joint work helps to modernize the analytical capacity of the brewing industry with the development of molecular biological methods for the diagnosis of microorganisms in beer", recalls Ivana Radomirova, executive director of SPB. Previous DNA studies of the metagenome of Bulgarian beer by CBH identified 140 species of micro-organisms in beer, including lactic acid bacteria. They are usually sensitive to the antibacterial properties and effects of hops, and do not normally multiply at low temperatures.
Dr. Sergey Ivanov, head of the CBH and leader of the team that developed the new method, commented that it is becoming more and more fashionable, especially in craft beers, for beers with a more pronounced sour aroma-taste profile to appear. For this purpose, lactic acid bacteria are used, which form such a taste. Recently, more and more probiotic beers are being developed with the controlled addition of lactic acid starter to the beer, which are beneficial for the microflora of the stomach.
But even if this is the goal, microbiological control in brewing should be even stricter. In principle, lactic acid bacteria are undesirable and therefore their content in beer is constantly monitored, which requires time-consuming laboratory work. If production supervision is not accurate, the level of these microorganisms can quickly exceed 1 million/ml and spoil the harmonious taste of the beer. The new method of the Bulgarian scientists allows the quick and precise measurement of the amount of lactic acid bacteria in the beer by means of qPCR.
"Compliant and standardized with the traditional practices imposed in the industry, the procedure we developed is more accurate, as it also considers microorganisms that are not detected by classical methods. The new control procedure ensures their detection even at very low concentrations and tracking their change during the brewing process. The molecular biological method allows detection of even a few bacteria at early stages of their development, so that their concentration can be maintained at acceptably low levels with corrective measures," adds Dr. Ivanov.
The method developed by Bulgarian scientists is a good example of how molecular biology allows a number of procedures from research institutes to enter the brewing industry, including PCR technology. It is applicable for varietal identification of hops and barley, control of yeast strains, etc. The most capricious and difficult to control are the "living workers" in the composition of beer - the yeast.
It is well known that brewer's yeast has a number of useful properties and at the same time is very important for the quality of the drink. It is no coincidence that 27 scientific reports and posters on the microbiology of beer were presented at the international congress of the European Brewing Convention in Madrid last year. In this context, the new method of the Bulgarian scientists is unique and has no analogue in European brewing science.
In the current year 2023, the development of qPCR procedures for the detection of the traditional brewer's yeasts, which are responsible for fermentation, is expected. The goal of the researchers is to renew and modernize the analytical and research capabilities of brewers in the coming years. This will increase the quality of Bulgarian beer, reduce losses in the industry and naturally - increase consumer satisfaction.
Follow on and
Write to us at
Copyright (c) Novinite.com. Published with permission via Big News Network news agency