Does sterilization of food products destroys the toxins & spores?
For shelf stable products with PH>4,5 the target organism (most heat resistant pathogen) is C botulinum type A with a decimal reduction time of D121°C = 0,21 min
The legally proposed reduction is 12 times D , so 3 minutes at 121°C (=botulinum cook)
So in fact you reduce the population by 12 logs for the target organism, resulting in a state where the probability of survivors must be reduced to very low because of likelihood of outgrowth to high numbers.
They also call this commercial sterile (and this does not mean 0 survivors. If a product has min 3 min at 121°C then it is safe for consumption.
Be carefull : many factors are having an effect on this general rule (pe. pH , the climate of the country where one wants to sell the products, etc ....)
Does sterilization of food products destroys the toxins & spores ?
It depends on the toxin, bot toxin would be destroyed by the heat required to produce a commercially sterile product in an a low acid canned food. B. Cereus toxin is heat stable and staph and certain other enterotoxins are are also relatively heat stable so you have to identify the potential toxins and research each individually.
Regarding spores, LACFs are considered to be commercially sterile, which means that the spores that can grow at normal temperatures have been killed (technically reduced my enough log cycles to overcome the potential load), but thermophilic spores may still be present. These will not germinate and grow at normal storage temperatures but may still be present in the product and can grow if the product is held at elevated temperatures.
Unfortunately, as with most questions related to food microbiology, there is not a one size fits all answer to a question like this.
Nice answers.
It is highly tempting to use positive words like kill, eliminate, destroy to categorise the results of thermal reduction of bacteria but it can also lead to confusion when comparing different thermal treatments.
These 2 links offer some details of the technical aspects of thermal destuction processes -
http://www.fao.org/d...7e/AI407E22.htm
http://www.fao.org/d...8E/R6918E02.HTM
As an example of carefully presented material, this is an extract from a FSA risk assessment for C.botulinum in infant foods.
Infant botulism was first recognised in 1976, since when over 1,500 cases have been reported in more than 15 countries. The condition is caused by ingestion of C. botulinum spores which leads to subsequent colonisation and toxin production in the gastrointestinal tract.
Exposure via food may arise through consumption of commercial baby foods which do not receive sufficient heat treatment to destroy all C. botulinum spores. It may also occur via consumption of home made baby foods and other foods not aimed at children, which may contain spores. Opened foods may also become contaminated with spores from the environment, particularly where there is prolonged use.
The safety of baby foods needs to be considered in the context of the processes applied to them and their likely effect on levels of C. botulinum spores in the foods. There are two main heat processes designed to achieve a ‘safe’ reduction in spores of C. botulinum. Proteolytic C. botulinum spores are ‘destroyed’ by a process of 121°C for 3 minutes, the F03 process or ‘botulinum’ cook. This ‘destruction’ process is designed to reduce the level of the spores by 12 log units and foods where this process has been applied are considered to be safe with regard to C. botulinum as the risk of the organism being present is reduced to an acceptable level. Non-proteolytic C. botulinum spores are less heat resistant and are ‘destroyed’ by a process of 90°C for 10 minutes. This process is designed to achieve only a 6 log reduction but, in the context of non-proteolytic C. botulinum and the foods in which it is a hazard, this is considered to reduce the risk of it being present to an acceptable level and foods processed in such a way are considered ‘safe’ (Table 4.2). The principle of a 6 log reduction being considered safe is consistent with the standards applied to foods for the safe reduction of a variety of other foodborne pathogens .
FSA, 2006, infant botulism report.pdf 206.07KB 35 downloads
Rgds / Charles.C