Low- & non-alcoholic beer may be a breeding ground for food-borne bugs
A new study has found that compared to regular-strength beer, low- and non-alcoholic beers may be a breeding ground for food-borne pathogens like E. coli and Salmonella, which can be introduced during manufacturing, storage, or pouring.
Driven by a rise in wellness culture, there’s been a shifting trend in the global drinks industry towards producing low- and non-alcoholic beverages, including beer. In the US, UK, and Australia, brewers can label a beer ‘non-alcoholic’ if it contains less than 0.5% alcohol by volume (ABV).
There are obvious benefits to drinking beer with no or low alcohol content; it contains vitamins and minerals, and studies have shown that, compared to regular beer, it has cardiovascular benefits. However, a new study by researchers at Cornell University has found that removing alcohol from beer may create the perfect environment for the growth of food-borne pathogens introduced during manufacturing, storage, or pouring.
“When you remove the alcohol, it’s really no longer a traditional beer,” said Randy Worobo, one of the study’s co-authors. “We suspected that food-borne pathogens would be able to grow without the presence of alcohol. We were correct. At that point, you must consider nonalcoholic beer like food and make sure that all parameters are met guaranteeing product safety.”
Traditional beer contains a number of factors that prevent pathogen growth. Ethanol concentration, bitter acids from hops, low pH, high amounts of carbon dioxide, low oxygen, and a lack of nutritive substances all contribute to keeping beer pathogen-free.
“Craft manufacturers of nonalcoholic beer sometimes follow a traditional beer-making process,” said Ann Charles-Vegdahl, another of the study’s authors. “But in the end, brewers add additional material for flavoring and aroma – like hops – to non-alcoholic beers, which could potentially introduce contamination.”
The researchers took beer samples with an ABV of less than 0.5% (non-alcoholic) or 3.2% (low-alcoholic) and added three food-borne bacterial pathogens: E. Coli, Salmonella, and Listeria. Beers with three different pH levels – 4.20, 4.50, and 4.80 – were prepared and the beers were stored at two different temperatures, 39 °F (4 °C) and 57 °F (14 °C), for two months.
E. coli and Salmonella grew and survived in the beer at both temperatures, regardless of the pH and whether the beer was low- or non-alcoholic. Both bacteria doubled when stored at 57 °F in all the pHs tested. Listeria was undetectable at both temperatures.
Based on their findings, the researchers recommend that low- and non-alcoholic beers be pasteurized to achieve commercial sterility and that sterile filtration and the addition of preservatives should be considered to reduce microbial risk. Further, they say that non-alcoholic beers served on draft – from a cask or keg – could increase the risk of pathogens and suggest that kegs, tubing and beer-pouring faucets be sanitized regularly.
“Without alcohol in beer, you’re removing a lot of the safety net against food-borne pathogens,” Worobo said. “Without that protection that alcohol provides, manufacturers must take into consideration how pathogens may be incorporated from raw products during the processing.”
The study was published in the Journal of Food Protection.
Source: Cornell University