Who is using water activity as a food safety parameter?

Hi all!

Just wanted to check who is using water activity as a food safety parameter and how you do it.

I hope you have some experience with this.

Regards,

FSSM

Well it seems I have made a bad question, either because everybody use it usually, or very few people use this tool for food safety.

Now I would like to ask a more specific questions about this.

1. Does anybody have used water activity to extend shelf life for dry products?

1.1 What would be a concern for a food ingredient or additive (starch, maltodextrins, poliols, hydrocolloids, natural and artifitial sweetners, etc) beeing "expired"?

1.2 What do you consider a food safety parameter for an ingridient or additive?

2. Is it usual that a food safety parameter go out of a critical limit during warehousing of food ingredients or additives?


Regards,

FSSM

Dear FSSM,

I hv never personally measured water activity but it seems that Google has done it many times , eg

http://en.wikipedia..../Water_activity

For the other "simple" queries, maybe some answers coming in after weekend -

Rgds / Charles.C

I have used water activity as part of the justification in a hazard analysis as to why pathogens may or may not survive or grow. A very low water activity could extend shelf life.

The term 'expired' might mean different things depending on where the product was made and what the country's regulations are on shelf life declarations. In the U.S., such a statement is often precaurtionary for quality reasons and not food safety reasons. Ask the supplier what the date means and how they selected the date. This should help your decisions.

I have not seen dry storage parameters as critical control points. I've only seen this for temperature controlled (cold) storage.

As Cathy said, I would use Aw as a HACCP tool to decide which pathogens are of concern but not as a routine process parameter. Also be aware that Aw could give you a false sense of security. The Aw of chocolate for example is very low but chocolate is still able to support Salmonellae (if not let the bacteria grow) and in high fat foods, Salmonellae can cause illness with tens of cfu per g not the normally considered numbers. Also dried foods are commonly hygroscopic so starches could over time absorb water from the atmosphere. This is particularly important if extended shelf lives with the consumer are common although may cause quality issues before it causes a food safety one.

Well it seems I have made a bad question, either because everybody use it usually, or very few people use this tool for food safety.

Now I would like to ask a more specific questions about this.

1. Does anybody have used water activity to extend shelf life for dry products?

1.1 What would be a concern for a food ingredient or additive (starch, maltodextrins, poliols, hydrocolloids, natural and artifitial sweetners, etc) beeing "expired"?

1.2 What do you consider a food safety parameter for an ingridient or additive?

2. Is it usual that a food safety parameter go out of a critical limit during warehousing of food ingredients or additives?


Regards,

FSSM

IMHO...

1. I use archenniues approach to decide our product shelf life.. and that approach using aw as parameter.. but to make it simple in day to dfay practical, i use moisture content,... thats parameter relation with cacking properties of powder.. ussually MC target is ± 4% and product tend to cack if the moisture > 5%..

1.1 I assume thats ingridients in powder form, and parameter being expired are for physically i use cacking or lumpy properties, and change of sensory parameters ( appearance, color etc), thats the simplest way.. if you want more detail you can check moisture content and micro test.

1.2 micro content, heavy metal content

3. yes.. you can see expire date of product.. thats the basic of food safety parameter...


thats my opinion ..


rgds

AS NUR

Well it seems I have made a bad question, either because everybody use it usually, or very few people use this tool for food safety.

Now I would like to ask a more specific questions about this.

1. Does anybody have used water activity to extend shelf life for dry products?

1.1 What would be a concern for a food ingredient or additive (starch, maltodextrins, poliols, hydrocolloids, natural and artifitial sweetners, etc) beeing "expired"?

1.2 What do you consider a food safety parameter for an ingridient or additive?

2. Is it usual that a food safety parameter go out of a critical limit during warehousing of food ingredients or additives?


Regards,

FSSM

Hi FSSM

1. Not to extend but to achieve shelf life by having a maximum moisture level
1.1 The simple fact it had expired meaning it had been around for a long time - I would resample and test
1.2 You will need to consider relevant Physical, Chemical and Microbiological Hazards, measures to control them and critical limits. For example filtration using say a 1mm sieve to remove foreign bodies.
2. Possibly : Contamination from dirt or pests or conditions that allow microbiological deterioration

Regards,

Tony

A very low water activity could extend shelf life.

That is where I´m triying to get, would anyone do Wa check to an "expired product" insted of a microbiological test to extend shelf life?

I think Wa would be a photograph of the product at that moment, but won´t tell me the story if Wa have been up from the limit for a pathogen to let it multiply at any other period of time.

RH is related to Wa and if RH is usually under 65%, then Wa wouldn´t be to high for certain pathogens, right?

The term 'expired' might mean different things depending on where the product was made and what the country's regulations are on shelf life declarations. In the U.S., such a statement is often precaurtionary for quality reasons and not food safety reasons. Ask the supplier what the date means and how they selected the date. This should help your decisions.

I have not seen dry storage parameters as critical control points. I've only seen this for temperature controlled (cold) storage.

Thanks,

FSSM

IMHO...

1. I use archenniues approach to decide our product shelf life.. and that approach using aw as parameter.. but to make it simple in day to dfay practical, i use moisture content,... thats parameter relation with cacking properties of powder.. ussually MC target is ± 4% and product tend to cack if the moisture > 5%..

1.1 I assume thats ingridients in powder form, and parameter being expired are for physically i use cacking or lumpy properties, and change of sensory parameters ( appearance, color etc), thats the simplest way.. if you want more detail you can check moisture content and micro test.

1.2 micro content, heavy metal content

3. yes.. you can see expire date of product.. thats the basic of food safety parameter...


thats my opinion ..


rgds

AS NUR

So I can focuse to food safety with micro and heavy metals, in the context of keeping products in good conditions during warehousing and caring not to introduce new food safety hazards, heavy metals won´t multiply, so it leaves micro.

Will water activity measurement give good information or is it water content or a history of RH that could predict if microorganisms have multiplied in a powder product?

Regards,

FSSM

1.1 The simple fact it had expired meaning it had been around for a long time - I would resample and test

Tony,

That is the logical way, but I want to skip micro testing having a sound scientific approach and just use maybe RH history.

For some products as other forum members comment, quality of functionality issues will appear first, before I start caring of microbiological load.

Regards,

FSSM

Tony,

That is the logical way, but I want to skip micro testing having a sound scientific approach and just use maybe RH history.

For some products as other forum members comment, quality of functionality issues will appear first, before I start caring of microbiological load.

Regards,

FSSM

Dear FSSM

What king of products are you talking about? Are they packed? Are they meat products?

BEst regards
Esther

Dear FSSM

What king of products are you talking about? Are they packed? Are they meat products?

BEst regards
Esther

Esther,

They are food ingredients, like starch, maltodextrin, xanthan gum, etc. packed in paper bags, some with internal plastic lining, others with plastic bag inside, some in carton drums.

Regards,

FSSM

Esther,

They are food ingredients, like starch, maltodextrin, xanthan gum, etc. packed in paper bags, some with internal plastic lining, others with plastic bag inside, some in carton drums.

Regards,

FSSM

Dear FSSM

First of all, sorry for such a delay.

In my opinion, all yours products are low risk ones. A expired date will probably refer to quality parameters but not safety ones.

Regarding the packaging material, I quess that it can not stop the hygroscopic thing, but you can check that with your supplier. In this case, you should ask your supplier the best storage conditions, mainly the one related to HR. Besides you should avoid water entering in your storage.

But the more important thing is what are your product used for? or how are yours products going to be used by your client? Do not forget that any food, even any surface ( wood, stone, brick...) can support bacteria but that is not the problem; the issue to be worry about is not to let bacteria growth.

Agree with you, it is unuseful to check pathogens or Aw on final products during storage.The sensible thing is to have a good control of the storage conditions. Be aware that Aw and moisture are two different things and here the only one related to food safety is Aw.

I hope this can help

Regards
Esther

What if the products are frozen? If we eventually did before the products are froze, can we actually predict the stability and safety of the product? Or it will be waste of time since frozen storage already decrease the risk of microbial growth.

 

 

Hope anyone can share their opinion. Because I am very new in the industry and wanted to learn more. :)

Dear FSSM

First of all, sorry for such a delay.

In my opinion, all yours products are low risk ones. A expired date will probably refer to quality parameters but not safety ones.

Regarding the packaging material, I quess that it can not stop the hygroscopic thing, but you can check that with your supplier. In this case, you should ask your supplier the best storage conditions, mainly the one related to HR. Besides you should avoid water entering in your storage.

But the more important thing is what are your product used for? or how are yours products going to be used by your client? Do not forget that any food, even any surface ( wood, stone, brick...) can support bacteria but that is not the problem; the issue to be worry about is not to let bacteria growth.

Agree with you, it is unuseful to check pathogens or Aw on final products during storage.The sensible thing is to have a good control of the storage conditions. Be aware that Aw and moisture are two different things and here the only one related to food safety is Aw.

I hope this can help

Regards
Esther

9-year old thread.

 

There is no post ??????

 

Hello!  Regarding using water activity to extend shelf life: we will measure water activity for an ingredient/blended bulk then compare it to the initial water activity we recorded when we first received/made the material- if they are close, we assume no water was added to the system and we forgo microbiological testing and extend the shelf life for ~3 to 6 months.  If there is a big change, we will send a sample out for external microbiological testing.  

 

Jacqui

Hello!  Regarding using water activity to extend shelf life: we will measure water activity for an ingredient/blended bulk then compare it to the initial water activity we recorded when we first received/made the material- if they are close, we assume no water was added to the system and we forgo microbiological testing and extend the shelf life for ~3 to 6 months.  If there is a big change, we will send a sample out for external microbiological testing.  

 

Jacqui

 

Hi Jacqui,

 

Thks for input.

 

One might imagine that any Validation might relate to the absolute initial value of Aw

 

"big change" = ??