Canned foods lack 02, so a contamination means the toxin builds up over time instead of breaking down quickly, which is how it is so widespread without constantly killing people.
The go-to methods of preventing C. botulinum multiplying in canned foods is pressure-boiling the food at high temperature for a few minutes and adding acid (i.e. vinegar) and/or salt. The first one kills the spores, the latter two kill bacteria emerging from remaining spores. If this doesn’t work too well, the bacteria multiply and start producing the toxin and the gases.
There are also the options of dehydrating the food with salt or smoking, or adding lots of sugar. But the former two are mostly done to meat, to my knowledge, and the latter one is just sweets or honey.
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The go-to methods of preventing C. botulinum multiplying in canned foods is pressure-boiling the food at high temperature for a few minutes and adding acid (i.e. vinegar) and/or salt. The first one kills the spores, the latter two kill bacteria emerging from remaining spores. If this doesn’t work too well, the bacteria multiply and start producing the toxin and the gases.
There are also the options of dehydrating the food with salt or smoking, or adding lots of sugar. But the former two are mostly done to meat, to my knowledge, and the latter one is just sweets or honey.