|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|4558923||1413196||2017||6 صفحه PDF||سفارش دهید||دانلود رایگان|
• Growth of Staphylococcus aureus in milk powder after its reconstitution.
• Production of staphylococcal enterotoxins was regularly detected during the 48 h.
• At 25 °C, enterotoxin was detected in most samples after 24 or 48 h.
• S. aureus numbers exceeded the critical threshold of 105 cfu ml−1 after 7 o’clock.
• The first positive detection SEA was at 8 h.
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 101–102 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 102 and 105 cfu g−1 of toxigenic strains of S. aureus and then stored as reconstituted milk for 48 h at 4, 15, and 25 °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 °C, the production of staphylococcal enterotoxins (SEs) was detected as early as after 7 (SEB) or 8 (SEA) hours of storage; at 15 °C as early as after 48 h (SEA, SEB). With inoculation of low counts of S. aureus (complying with legislative requirements) only at 25 °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.
Journal: Food Control - Volume 73, Part A, March 2017, Pages 2–7