Microbiological Profile and Storage Temperatures of Egyptian Rice Dishes

Cooked rice and other dishes containing rice (172 samples) were tested for aerobic colony count (30°C), Salmonella, Shigella, Staphylococcus aureus, and presumptive Bacillus cereus. Salmonella was isolated from a sample of Oriental rice that was prepared in a five-star hotel kitchen. Shigella was isolated from a sample of boiled rice from a four-star hotel kitchen. Nineteen percent of the samples were contaminated by S. aureus, and 73% of these contained more than 103/g. Forty percent of the samples were contaminated by B. cereus, 31% of these contained more than 103/g. Rice was more frequently stored at safe temperatures (>55°C) in four- and five-star hotels than in any other type of establishment or that which was sold by street venders. Aerobic colony counts (30°C) per g were usually quite low when rice was held at temperatures of 55°C or higher. These counts generally became progressively higher as the temperature decreased, often reaching quantities exceeding 106 when temperatures were 44°C or below. This was particularly so when the temperature range was 25–34°C. These counts were lower for fried and Oriental rice than for boiled rice, rice and vegetables, kushari (a mixture of rice, macaroni and lentils), and rice and shirea (thin, wheat macaroni).