Posted 27 August 2010 - 05:40 AM
Not so, it depends on the volume stored and the conditions, I would imagine in a several kilo tub of rice, near the bottom there would be significant numbers of anaerobic microenvironments:
"In air-packaged products, aerobic spoilage organisms provide sensory signs of spoilage before the formation of toxin by C. botulinum. However, even in air packaging it is possible for anaerobic micro-environments to exist and toxin may form if the product is subject to severe time/temperature abuse. For that reason, the country where the product is consumed may still require water phase salt as a barrier to growth"
http://www.ifr.ac.uk..._report0707.pdf
Crikey we're not disagreeing again!
The article you are quoting from is "Clostridium botulinum in
vacuum packed (VP) and modified atmosphere packed (MAP) chilled foods - IFR"
The quote you have given relates to Smoked Fish.
Some extracts
A total of 527 independent challenge test datasets with storage at 8°C were considered, and 100 of these were positive for toxin at day 10. Of the 100 positive tests, 56 were with raw or smoked fish, 41 were with sterile or pre-cooked food, two with sous-vide foods, and one with salted ham (Table 8). Based on these data there is a possibility that if contaminated with spores of non-proteolytic C. botulinum, raw or smoked fish could become toxic within 10 days at 8°C.
Trout produced by major UK manufacturers is generally packed with the presence of oxygen (i.e. not VP) in order to control the potential for C. botulinum growth and toxin formation.
The 2005 Food Code states that except for fish that is frozen before, during, and after packaging, a food establishment may not package fish using a reduced oxygen packaging method.
Various challenge test studies tend to support this view, with toxin only being found in products stored at temperatures of 12°C and above, and usually accompanied by overt product spoilage.
MAP/VP products, is that while challenge test data may indicate the potential for growth and toxin formation, it is known that many thousands of millions of packs of product of this type have been sold around the world, with no evidence of botulism having occurred.
The article also reports no toxin production in rice.
How is that boy of yours doing anyway?
Regards,
Tony
Edited by Tony-C, 27 August 2010 - 05:43 AM.
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