December 1/Laval, Canada/Journal of Technology & Science -- "A fortified beverage powder intended for developing countries was composed of vitamins, minerals, sugar and orange flavor. Organic acids were also added as food additive," investigators in Laval, Canada, report.
"The antibacterial efficacy of reconstituted beverage was tested on three strains of enterobacteria (Escherichia coli, Salmonella Typhi and Serratia liquefaciens). The antibacterial efficacy of beverage containing organic acids (ascorbic and citric acids) as compared to the same beverage containing mineral acid was successfully demonstrated. The greatest inhibitions of bacterial growth were observed in the presence of organic acids. The antibacterial activity was significant depending on initial bacterial concentration and time of contact. However, S. liquefaciens was not detected in the beverage containing organic acids regardless of the bacterial concentration added. At a concentration of 10(3) cells/mL, the bacterial population of S. liquefaciens, E. coil, S. Typhi and the mixture of the three bacteria reached an undetectable level in the beverage containing organic acids after five, 180 and 60 minutes of contact, respectively," wrote A.S. Guenier and colleagues, University of Quebec.
The researchers concluded, "The inhibitory effect of pathogenic bacteria was closely related to the reduction of the beverage pH and to the concentration of undissociated organic acids."
Guenier and colleagues published their study in Food Research International ("Antibacterial Capacity of a Reconstituted Fortified Beverage Used as a Nutritional Supplement." Food Research International, 2010;43(9):2321-2328).
For additional information, contact M. Lacroix, University of Quebec, INRS Institute Armand Frappier, Research Laboratories Science Applied Food, 531 Blvd. Prairies, Laval, PQ H7V 1B7, Canada.
From the December 6, 2010, Prepared Foods E-dition