Water Activity 101: Mastering the Basics of Water Activity in Food Safety

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Understand the power of water activity. Water activity is not 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 condensed in this 20-minute webinar. You’ll learn:
-What water activity is
-How it’s different from moisture content
-Why it controls microbial growth
-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 eight years. 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?”
Read more:
www.metergroup...

[@sb7323]

Perfect presentation of such a complex subject. Many thanks. BTW, honey and cookie example was perfect.

[@baharshokuienia6598]

Amazing presentation!

[@harijonoh1118]

Thank you for the great easy to understand concept

[@METERGroup]

Glad to hear that!

[@Yunnanalin]

Thank you so much, very helpful.

[@Outdoorseyguy]

Where is the rest of the talk? Looking for part 2 with no luck. Please post.

[@METERGroup]

Thank you for your comment: www.metergroup.com/food/events/water-activity-102-microbial-growth/

[@alinajunnaaquino9793]

This was such a big help~ Thank you!

[@Sadhell0012]

That is amazing information thanks a lot

[@METERGroup]

Glad it was helpful!

[@obedalex]

Excelent, I understand now a little more.

[@METERGroup]

Glad it helped!

[@mpodevin]

Did the end of the video get cut off?

[@dininordin2888]

Hi, i have a question, Does the "bound water + free water = MOISTURE CONTENT" ? or is there any other types of water that will equivalent to moisture content?

[@METERGroup]

You might think that the "bound water + free water" would equal the total moisture in a product, but it doesn't always. There can be other forms of liquids that could contribute to a moisture content value (ex. alcohols, acids, etc) or if heating the sample up, burning carbohydrates creates water. Both of those scenarios would have a higher %MC than from water alone. On the flip side, sometimes not all of the water can be extracted in a moisture content determination - the water is too tightly bound and would need some serious energy to remove it. In this case, the %MC would be lower.

[@justwow967]

Hey, can u make a video on equilibrium moisture content?

[@METERGroup]

Thank you for your input. We look forward to discuss your request.

[@dr.punitsingh8215]

please send the link of webinar

[@METERGroup]

You can find all materials here: www.metergroup.com/food/events/water-activity-101-master-the-basics/

[@abdullahmohamed2027]

how to measure the vapor pressure of pure water

[@mitikuamanumesele3975]

did dry basis give negative moisture content value??

[@METERGroup]

The problem with dry basis is that it can calculate a %MC over 100%. It doesn't work for products with a moisture content above 50%. Here is an example: dry basis = (wet weight - dry weight) / dry weight *100% 10 g (wet product) - 5 g (dry product) / 5 g (dry product) *100% = 100% Logically, we can see that half the weight was moisture, so it should be 50% MC and it is using wet basis.