V originále
Staphylococcus aureus is the causative agent of staphylococcal enterotoxicosis foodborne illnesS. Milk powder and whey powder are at risk of contamination by coagulase-positive staphylococci, which reflects the requirement for microbiological examination of foods listed in Regulation (EC) 2073/2005, as amended. Microbiological criteria for coagulase-positive staphylococci are up to 10(1)-10(2) cfu g(-1). This study evaluates the possibility of survival and growth of S. aureus in milk powder after its reconstitution. Powdered milk was inoculated with 10(2) and 10(5) cfu g(-1) of toxigenic strains of S. aureus and then stored as reconstituted milk for 48 h at 4,15, and 25 degrees C. Staphylococcal growth and production of staphylococcal enterotoxins A, B, and C (SEA, SEB, and SEC) was regularly detected during the 48 h storage period. With inoculation of S. aureus high counts at 25 degrees C, the production of staphylococcal enterotoxins (SEs) was detected as early as after 7 (SEB) or 8 (SEA) hours of storage; at 15 degrees C as early as after 48 h (SEA, SEB). With inoculation of low counts of S. aureus (complying with legislative requirements) only at 25 degrees C, SEs production was detected after 24 (SEA, SEB) or 48 (SEA, SEB, SEC) hours. Model experiments evaluated SEs consumer risk resulting from extended storage of reconstituted milk at improper temperatures. (C) 2016 Elsevier Ltd. All rights reserved.