May 14/Science Letter -- According to recent research from Jaen, Spain, "The low pH and acid content found in sports and energy drinks are a matter of concern in dental health. Raising the pH may solve this problem but, at the same time, increase the risks of spoilage or presence of pathogenic bacteria."

"In the present study, commercial energy drinks were adjusted to pH 5.0 and challenged with Listeria monocytogenes (drinks A to F), Staphylococcus aureus, Bacillus cereus, and Bacillus licheniformis (drink A) during storage at 37 degrees C. L. monocytogenes was able to grow in drink A and survived in drinks D and F for at least two days. Addition of enterocin AS-48 (1 mu G/ML final concentration) rapidly inactivated L. monocytogenes in all drinks tested. S. aureus and B. cereus also survived quite well in drink A and were completely inactivated by 12.5 mu g/ml enterocin AS-48 after two days of storage or by 25 mu g/ml bacteriocin after one day. B. licheniformis was able to multiply in drink A, but it was completely inactivated by 5 mu g/ml enterocin AS-48 after two days of storage or by 12.5 mu g/ml bacteriocin after one day," wrote P.M. Viedma and colleagues, University of Jaen (see also Food Protection).

The researchers concluded, "Results from the present study suggest that enterocin AS-48 could be used as a natural preservative against these target bacteria in less acidic sport and energy drinks."

Viedma and colleagues published their study in the Journal of Food Protection ("Antibacterial Protection by Enterocin AS-48 in Sport and Energy Drinks with Less Acidic pH Values." Journal of Food Protection, 2009;72(4):881-884).

For additional information, contact A. Galvez, University of Jaen, Faculty Ciencias Experimental, Dept. of Ciencias Salud, Area Microbiology, Jaen 23071, Spain.

From the May 26, 2009, Prepared Foods E-dition