12 replies to this topic

[Tresa]

Hi everyone,

As a bakery, we produce biscotti, cookies, and muffins. Water activity in our products is too low to support growth. Do you recommend testing for water activity or moisture content? The quality of the product (texture, hardness) is our primary concern. Your input would be greatly appreciated.

[Setanta]

If you get water from a municipality, they should be able to give you a certificate of annual water testing. However, you may want to get a test done, just to ensure you aren't starting off with contaminated water.

[Marloes]

I would say it is not directly needed for your food safety. If your recipe's include baking time and temperature, and these are well-validated, this should be enough.
It can however be a pleasant addition to your quality management system. Perhaps over- or under baking (drying) can be detected and improve overall product quality.

 

I will add that I have a little bit of experience with aW monitoring using a in-house machine. The one we rented would require a sample to be crushed/blended into a small container and put into the machine until it had reached a equilibrium. For our high aW and heterogenous products this would take about 30 minutes. Which can be very time consuming. I will sit next to the machine all day and only get maybe 12 samples done a day.

 

You can probably rent a machine for quite cheap and do some testing yourself.

[Scampi]

from a quality perspective, test moisture content  water activity has nothing to do with the crispness/dryness of your finished goods

 

Do not waste your time on water activity---all that will tell you is how fast a pathogen can theoretically travel through your product, lower number, less likely, higher number, more likely

 

Moisture levels on the other hand can capture fats as well as liquid which all contribute to the overall sensory qualities of your finished goods

 

i.e. a banana muffin where 1 less than usual bananas were used will have a lower moisture content after baking than the normal recipe as less moisture was introduced at the beginning  OR exact same recipe, but the bake time was an extra 10 minutes---more moisture will have been lost due to evaporation

 

the list goes on and on

[olenazh]

Agree with Marloes: it's more for quality, not food safety. In addition, from my experience working for bakeries - they never checked wA of products, relying more on their experience to have constantly quality products

[foodguy63]

I second Scampi's comment.

 

There are also some methods out there that I've used in the meat industry manufacturing deli meats called "Texture" and "Slice-ability". We used a pneumatic hand pump that would record the pressure at which the sample would cut or squish. Not sure if something similar could be developed to quantify some of the "mouthfeel" characteristics associated with baked goods, but I've often thought about it myself.

[Bansal]

Hi tressa,

 

As per my knowledge i dont think u need to do water activity or moisture.

 

organoleptic testing would be the best testing for you. You can collect sample for (organoleptic testing)/ batch or per shift depending on the variation in your process.

 

Thanks

[bornyesterday]

Water sources are a concern on the input side as you may be considering them an ingredient. All ingredients (even ice) should have some level of checking.

The moisture content of finished product might also be a concern if the finished product is not given adequate time to cool prior to packaging.

[Marloes]

I second Scampi's comment.

 

There are also some methods out there that I've used in the meat industry manufacturing deli meats called "Texture" and "Slice-ability". We used a pneumatic hand pump that would record the pressure at which the sample would cut or squish. Not sure if something similar could be developed to quantify some of the "mouthfeel" characteristics associated with baked goods, but I've often thought about it myself.

I know that in the chips/crisp industry they use a crispiness tester. By crushing the chips and recording the sound of the snap they can determine if it has the right crispiness.

[moskito]

Hi,

 

in our bakery we are specifying both for each product during development - water activity and moisture content. Frequency of measurements of water activity will be defined by the type of products, e.g. in the case of cookies with aw of 0,2 - 0,3 no measurement will be performed on regular basis.

In general we don't use preserving agents in our recipes.

Therefor water activity becomes of interest especially for products with high values like cakes, stollen, ginger bread etc. 

 

Rgds

moskito

[mihaellaaa]

Lucrez intr-o fabrica de biscuiti.
Am avut probleme la un produs pentru care Umiditatea=12 si activitatea apei aw = mai mare de 0.6.
A dezvoltat mucegai.
Mi-ar face mare placere sa tinem legatura.(legatura fiind fabricarea biscuitilor)

[Charles.C]

Lucrez intr-o fabrica de biscuiti.
Am avut probleme la un produs pentru care Umiditatea=12 si activitatea apei aw = mai mare de 0.6.
A dezvoltat mucegai.
Mi-ar face mare placere sa tinem legatura.(legatura fiind fabricarea biscuitilor)

Please communicate in English.

[AJL]

Hi, I am also considering doing some water activity testing, as part of the validation for HACCP, to show that the growth of pathogens will not be supported by the products.
Thoughts? It's more relevant than moisture content right?