Survival and growth of Enterobacter sakazakii in infant rice cereal reconstituted with water, milk, liquid infant formula, or apple juice

• Published in: Journal of applied microbiology 2005-01, Vol.99 (4), p.844-850
• Main Authors: Richards, G.M, Gurtler, J.B, Beuchat, L.R
• Format: Article
• Language: English
• Subjects: animal pathogenic bacteria; Animals; apple juice; Beverages; Biological and medical sciences; breakfast cereals; Colony Count, Microbial - methods; Cronobacter sakazakii; Cronobacter sakazakii - growth & development; Edible Grain - microbiology; Enterobacter sakazakii; food contamination; Food Handling - methods; Food Microbiology; foodborne illness; Fundamental and applied biological sciences. Psychology; human health; Humans; Hydrogen-Ion Concentration; Infant; infant foods; Infant Formula; infant formulas; infant rice cereal; Malus; Microbiology; Milk; Oryza - microbiology; Oryza sativa; reconstituted foods; rice products; Temperature; temperature abuse; Water
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2005.02656.x

Aims:  To determine survival and growth characteristics of Enterobacter sakazakii in infant rice cereal as affected by type of liquid used for reconstitution and storage temperature after reconstitution. Methods and Results:  A commercially manufactured dry infant rice cereal was reconstituted with water, apple juice, milk, or liquid infant formula, inoculated with a 10‐strain mixture of E. sakazakii at populations of 0·27, 0·93, and 9·3 CFU ml−1, and incubated at 4, 12, 21 or 30°C for up to 72 h. Growth did not occur in cereal reconstituted with apple juice, regardless of storage temperature, or in cereal reconstituted with water, milk, or formula and stored at 4°C. The lag time for growth in cereal reconstituted with water, milk, or formula was decreased as the incubation temperature (12, 21 and 30°C) was increased. Upon reaching maximum populations of 7–8 log10 CFU ml−1, in some instances populations decreased to nondetectable levels during subsequent storage which was concurrent with decreases in pH. Conclusions:  Enterobacter sakazakii initially at very low populations can rapidly grow in infant rice cereal reconstituted with water, milk, or infant formula. Significance and Impact of the Study:  Reconstituted infant rice cereal can support luxuriant growth of E. sakazakii. Reconstituted cereal that is not immediately consumed should be discarded or stored at a temperature at which E. sakazakii and other food‐borne pathogens cannot grow.