The microbiological quality of cooked rice from restaurants and take-away premises in the United Kingdom.
The microbiological quality of 4,162 samples of cooked rice from restaurants and take-away premises in the United Kingdom was examined, including ready-to-eat rice purchased at point-of-sale and rice that was stored precooked for reheating on demand. The majority of point-of-sale cooked rice samples (1,855 of 1,972; 94%) were of acceptable microbiological quality, but 15 (1%) samples were of unacceptable quality (Bacillus spp. and B. cereus, > or = 10(5) CFU/g; Escherichia coli, > or = 10(4) CFU/g), indicating a potential risk to health. The prevalence of Bacillus spp., B. cereus, and E. coli was significantly greater in precooked stored rice than in point-of-sale cooked rice (P < 0.005 to 0.0005). Bacillus spp. (> or = 10(4) CFU/g), B. cereus (> or = 10(4) CFU/g), and E. coli (> or = 10(2) CFU/g) were present in 7%, 2%, and 9% of precooked stored samples, respectively, compared to 2%, 0.5%, and 1%, respectively in point-of-sale samples. Although final heating at the point of sale reduces the levels of microorganisms present in rice it will not inactivate the B. cereus emetic toxin if present. Rice from Indian premises was of poorer microbiological quality than that from Chinese and other premises. Although most point-of-sale cooked rice samples (94%) were of an acceptable microbiological quality, evidence from this study indicates that the microbiological quality of cooked rice sold from certain outlets in the UK is of concern.
Nichols
G L
GL
Environmental Surveillance Unit, Public Health Laboratory Service, Communicable Disease Surveillance Centre, London, UK. gnichols@phls.nhs.uk
Little
C L
CL
Mithani
V
V
de Louvois
J
J
D001407:Bacillus / Q000302:isolation & purification; D001409:Bacillus cereus / Q000302:isolation & purification; D001419:Bacteria / Q000302:isolation & purification*; D001420:Bacteria, Aerobic / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000302:isolation & purification; D005511:Food Handling / Q000379:methods* / Q000592:standards; D005516:Food Microbiology; D006358:Hot Temperature; D012275:Oryza / Q000382:microbiology* / Q000592:standards; D012147:Restaurants / Q000592:standards*; D006113:United Kingdom