Water activity 101: Master the basics of water activity in food safety

Water activity isn't an intuitive concept for most people. But once you understand it, it can give you the power to control moisture in food. Preventing microbial growth is just the start.
Get the essentials of water activity and how it can improve food safety and quality in this 20-minute webinar. You’ll learn:
- What water activity is and how to use it
- How it’s different from moisture content and why there's so much confusion on this topic
- Why it controls microbial growth and what levels to watch for
- How understanding water activity can help you control moisture in your product
Presenter Mary Galloway has been a lead scientist in the METER Food Research & Development lab for more than a decade. She specializes in using and testing instruments that measure water activity and its influence on physical properties. She has worked with many customers to solve their moisture-related product issues and frequently gets the chance to answer the question, “What is water activity?”
Want to learn more about water activity, moisture content, and how these measurements can make food, business, and life better? Visit the links below.
- Listen to the Water in Food podcast: go.meter.group/wif-podcast
- Get new tips, tricks and knowledge daily from METER Food on Linkedin: go.meter.group/linkedin
- Study up with the METER Knowledge Base: go.meter.group/knowledge-base
Chapters:
00:00 Welcome
00:49 What we'll cover
01:36 What is water activity?
03:53 Fugacity
04:44 Vapor pressure
06:10 What is moisture content?
08:41 Moisture content VS water activity
11:02 Example: Honey + Cookie
12:25 When to use MC, water activity
13:33 Moisture sorption isotherms
15:41 Microbial growth + water activity
18:28 Microbial growth limits
20:58 Food microbe risk categories
22:18 Case study: Microbial growth
25:02 Case study: Powder flow
26:51 Case study: Product formulation
31:01 Water activity + chemical reactions
32:37 Summary
34:04 Q&A: Lowering water activity
35:26 Q&A: When to measure aw
37:50 Wrapup