Question

To my understanding, spoiled food is not supposed to be consumed even after cooking it, since the heat may eradicate germs, but their toxines may be heat-resistant and thus still active. However, there are some purification tablets which are marketed as making spoiled water potable, apparently containing chlorine or iodine usually. Such tablets seem to be recommended also for water purification by the WHO. In the description of such tablets, their effect on toxines is never mentioned, and I wonder why toxines surviving the eradication of germs seem to be no problem here. Do water borne germs usually not synthesize toxines, or to a much lesser extent than food borne pathogens? Or do such tablets somehow inactivate their toxines?

Answer 1

While some bacteria in spoiled food can produce heat-resistant toxins, the pathogens typically found in water are not known for producing such toxins. Water purification tablets, containing chlorine or iodine, are designed to kill disease-causing microorganisms in water. Water treatment methods like these are aimed at making water safe for drinking rather than addressing toxin neutralization.

Step-by-step explanation:

The concern about the survivability of toxins produced by certain pathogens in spoiled food is indeed justifiable. When food spoils, certain bacteria can produce heat-resistant toxins that can remain active even after the food is cooked. However, the purpose of water purification tablets, which often contain chlorine or iodine, is to make water safe for drinking by killing microorganisms present in it. Unlike foodborne pathogens that may produce significant levels of toxins, waterborne pathogens typically pose a threat through infection rather than toxin production. Therefore, these tablets focus on neutralizing pathogens. While some resistant forms like cysts of the protozoan Cryptosporidium may survive chlorination, the majority are effectively killed. Moreover, the purification process does not usually address the neutralization of toxins.

It's also essential to acknowledge that treatment methods for food and water differ in their goals and methods. For example, pasteurization and irradiation are food treatment methods that aim to reduce microbial load while maintaining the sensory quality of food. However, water purification focuses primarily on making water potable by targeting pathogens.

Therefore, while water purification tablets don't address toxins specifically, the types of microbes that commonly contaminate water sources are generally not known for producing the heat-resistant toxins associated with food spoilage microbes. These tablets effectively kill microbes and are recommended by organizations like the WHO for making water safe to drink in situations where water quality is compromised.