Why foods go bad

Most foods spoil because of the growth of microbes. Preserving food is an attempt to limit microbial growth. Food can be preserved by drying, salting, chilling, or storing in air-tight containers.

• Drying is the most effective because microbial growth is inhibited.
• Salting is effective because it removes moisture, creating an environment where microbes cannot survive.
• Sugar coating can prevent bacterial cells from functioning correctly.
• Storing in air-tight containers is less effective because there are probably a lot of microbes on the food before you put it in the container. Some microbes are anaerobic, meaning they don't need oxygen.