Educator Resources for Virtual Labs: Understanding Water Activity

Many moist foods – like fresh fruit or raw meat – have high water activity and spoil quickly. But other foods that seem moist – like jam or pepperoni – don’t spoil as quickly. Why is this? Because enzymes and chemical reactions require water. If water activity is less than 0.6, almost all microbes, including bacteria, molds, and yeasts, stop growing. Students learn how food can be preserved against spoilage by lowering its water activity – whether by evaporating water away or binding it up. Virtual Labs – Understanding Water Activity familiarizes students with food science lab equipment and standard techniques for measuring water activity. The interactive animation guides students through both theory and practice, preparing them for experiences in a real lab.
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