Bacterial Contamination of Ready-to-Eat Foods and Fresh Products in Retail Shops and Food Factories

Abstract

Raw vegetables cut for salad, cooked salad, cooked rice, boiled noodles, bean curd, and cooked Japanese foods were purchased in 27 retail shops in Tokyo. Intact vegetables before being processed and ready-to-eat fresh salad products were obtained from two food factories located in the suburbs of Tokyo. Two hundred thirty-eight retail samples, 137 samples of intact vegetables, and 159 samples of fresh products were examined for aerobic plate count (APC), coliforms, Escherichia coli, Listeria spp., Staphylococcus aureus, and Bacillus cereus. The APC of retail foods were 2.1 to 5.7 log CFU/g, and the range for the coliforms was 0.1 to 2.3 log CFU/g. The APC and coliform values showed that the raw vegetables cut for salad were the most heavily contaminated among the six kinds of ready-to-eat foods examined. Although L. monocytogenes was not detected, two samples of raw vegetables and five kinds of cooked foods yielded Listeria spp. S. aureus was detected in one sample of Japanese cooked food. The APC of the intact vegetables were 2.9 to 7.3 log CFU/g upon arrival and 2.2 to 7.2 log CFU/g after 3 days storage at 10 degrees C. The APC of the fresh products were 3.4 to 7.6 log CFU/g upon arrival and 4.7 to 8.7 log CFU/g after 3 days storage at 10 degrees C. The isolation rates for coliforms were 6.1 to 50% for intact vegetables and 50 to 66.7% for fresh products. E. coli was detected only in the fresh products. B. cereus was isolated from 20.1% (17 of 81) of the intact vegetables and 9.2% (8 of 87) of the fresh products.

A risk assessment approach for fresh fruits

“…Bacillus cereus Portnoy et al 1976;Kaneko et al 1999;Becker and Holzapfel 1997;Splittstoesser et al 1983.…”

Microbiological quality of ready-to-eat foods of Tehran province

“…During the years 1986 to 1995, 104 outbreaks caused by B. cereus were reported in Taiwan, and this bacterium was noted to be the third most commonly implicated food-borne pathogen in this country (Pan et al, 1997). The increasing prevalence of precooked refrigerated food products could potentially exacerbate the problems associated with B. cereus (Choma et al, 2000;Nichols et al, 1999;Kaneko et al, 1996;Hatakka, 1998a, b).…”

“…The incidence of foodborne illness is increasing worldwide (Kaneko et al, 1996;Mead et al, 2009;Nguz, 2007). High counts of Escherichia coli and total coliform (TC) in foods usually indicates lack of hygiene in handling and production operations, inadequate storage and post-process contamination (De Sousa et al, 2002).…”

Why Food-Poisoning Bacteria Attached to Shredded Cabbage Are Not Efficiently Disinfected by Sodium Hypochlorite (NaClO)

“…Many studies have been undertaken to estimate the contamination of vegetables and fruits by microorganisms. [1][2][3] Vegetables are regarded as microbiologically safer than other unprocessed foods, such as meat, poultry, milk, eggs, and seafood. Although improvements in agronomic practices, processing, preservation, and distribution have made it possible to supply fresh produce of high quality to consumers all year round, outbreaks of food-borne disease due to consumption of fresh vegetables have recently increased.…”

“…26) In United States, it was reported that fresh lettuce contaminated with E. coli O157:H7 was the source of a food-borne outbreak. 1,5,27,28) S. aureus is a Gram-positive non-motile coccus having no flagella. Many people carry S. aureus, which often causes food poisoning associated with manually handled foods.…”