7 replies to this topic

[Anna21]

Hi everyone! 

 

I am not sure whether  I am asking this on the correct forum topic, however I will really appreciate your advice. 

 

I am busy developing a 6% fruit squash. Currently I am using Sodium Benzoate (0.84g/L syrup dosage) as a preservative, but I am also playing around with Sodium Metabisulphite, mainly for preservation.

 

However I am trying to limit the slight "burn sensation" it imparts on the beverage. I am struggling to find correct dosage levels of Sodium Metabisulphite. What is the minimum dosage of Sodium Metabisulphite I can add to my 6% syrup, for it to still be an effective preservative?

 

I see Codex Standard 192-1995 states that the Maximum level is 50mg/kg RTD product. Can one work the RTD amount back to the syrup when working with preservatives, as one will do with another raw material, e.g. sugar? 

 

E.g My mixing ratio will be 1:3 thus according to Codex my maximum level on the syrup will be 200mg/kg syrup. Is this correct? Does the amount of product to be preserved (1l) not remain the same, whether in the RTD form or the syrup form - meaning I can't work the preservative out in the above way? 

 

Lastly, should I decide to do away with the Metabisulphite - will the Sodium Benzoate at my current dosage level be enough for preservation of a 6% fruit squash syrup?

 

Thank you all! 

 

:)

Anna-MArt

 

 

 

 

[ABBIGAIL BEDASSIE NABBIE]

Hi Anna,

 

I assume the product is 6% juice...without carbonation?

 

The burning sensation is most likely an indication that your dosage

may still be too high....or perhaps the Na Meta is clashing with another

ingredient in your blend like citric acid etc.

 

I do not think the calculation of the amount needed will lead you in the

right direction. Formulation development is a trial and error process. You

need to start with a minimum dosage in your syrup and determine the maximum

allowable amount for your specific drink based on sensory evaluation of your RTD Product.

 

After this you will need to conduct a shelf life study to determine how effective

the Na Meta is in preserving the RTD product and preventing mold growth etc.

Since you are also interested in Sodium Benzoate, I suggest conducting a comparative

shelf life study. The final dosage of each preservative again will vary on the sensory

effect you want to project from your final product together with its effectiveness in preserving the product.

 

Product development takes a little time...be patient 

Hope this helps

[Anna21]

Hi Anna,

 

I assume the product is 6% juice...without carbonation?

 

The burning sensation is most likely an indication that your dosage

may still be too high....or perhaps the Na Meta is clashing with another

ingredient in your blend like citric acid etc.

 

I do not think the calculation of the amount needed will lead you in the

right direction. Formulation development is a trial and error process. You

need to start with a minimum dosage in your syrup and determine the maximum

allowable amount for your specific drink based on sensory evaluation of your RTD Product.

 

After this you will need to conduct a shelf life study to determine how effective

the Na Meta is in preserving the RTD product and preventing mold growth etc.

Since you are also interested in Sodium Benzoate, I suggest conducting a comparative

shelf life study. The final dosage of each preservative again will vary on the sensory

effect you want to project from your final product together with its effectiveness in preserving the product.

 

Product development takes a little time...be patient 

Hope this helps

 

Thank you very much for your reply! 

 

Yes this is a non-carbonated juice. I will do as you suggested with starting with a minimum dosage and working it up from there until I am happy with the taste. 

 

Do you perhaps have an indication for the minimum amount of Sodium Metabisulphite used for a preservative effect?

 

Thank you very much!

[pHruit]

You'll get some preservative effect from as little as 50mg/L, but whether that is enough in your product is something that you'll need to verify.
Don't forget that using sulphite you will end up with part of it as bound sulphites, and part as free sulphites - its only the latter that is going to serve a useful preservative effect, so you may want to be looking at e.g. 50mg/L as free rather than total SO₂, although this will of course depend on local regulations for maximum levels as these generally consider the total (free + bound) sulphite content.

 

The advantage that sulphites have over benzoate/sorbic acid is that it also provides some antioxidant function so can help protect colour in some juice products in addition to inhibiting microbiological growth, although there is of course a trade-off with potential allergen considerations if that's applicable in the markets into which you're selling the product.

 

For the benzoate option you may also want to consider at a benzoate/sorbate combination, as this can potentially more effective against a wider range of organisms.

 

[Anna21]

Thank you very much for the info! 

 

The product is a 6% Fruit juice squash (concentrate) to be diluted 1:3 with water. I have settled on using a combination of Sodium Benzoate (0.09%) and Potassium Sorbate (0.09%) which is in the recommended dosage level according to the FAO. 

 

Now I have a silly question: We pasteurize all of our fruit juices, however this squash is not pasteurized, preserved only. It has a fairly low pH of 2.80-2.82. 

 

If I understand correctly the preservatives added will NOT lower the total microbial count, as is the case with pasteurization, as the microbes naturally present in the fruit concentrate added will not be destroyed - their activity will only be suppressed? Is this correct? 

 

Will these two preservatives be effective in blocking microbial activity in this product, allowing it to be shelf stable for 8 months? 

 

If I receive the lab results back, I am expecting fairly high counts - how will I know the counts aren't toooo high for the preservatives added to be effective? 

 

thank you! 

You'll get some preservative effect from as little as 50mg/L, but whether that is enough in your product is something that you'll need to verify.
Don't forget that using sulphite you will end up with part of it as bound sulphites, and part as free sulphites - its only the latter that is going to serve a useful preservative effect, so you may want to be looking at e.g. 50mg/L as free rather than total SO₂, although this will of course depend on local regulations for maximum levels as these generally consider the total (free + bound) sulphite content.

 

The advantage that sulphites have over benzoate/sorbic acid is that it also provides some antioxidant function so can help protect colour in some juice products in addition to inhibiting microbiological growth, although there is of course a trade-off with potential allergen considerations if that's applicable in the markets into which you're selling the product.

 

For the benzoate option you may also want to consider at a benzoate/sorbate combination, as this can potentially more effective against a wider range of organisms.

[pHruit]

Unfortunately I think the answer to your queries is "maybe"...

Generally I wouldn't treat preservatives as a kill step in this application, but they will provide some degree of reduction in micro count. It is unlikely to achieve the full 5+ log kill you'd get from pasteurisation, but that isn't necessarily a problem.

 

In principle those preservatives should generally be able to achieve sufficient microbiological stability for that period of time, but this is of course dependent on the starting count.

You say you're expecting "fairly high" counts - what sort of figures are you envisaging?
Do you have raw material micro specs/results for your incoming products too?

As you're making a squash I'd guess that the juice component is a concentrate, and you really should see particularly elevated levels of spoilage organisms in this type of raw material - even if its not pasteurised there is usually some level of micro reduction from the evaporation stage(s), and I definitely know of processors who've validated this for 5-log kill in its own right.

Similarly if you're using a liquid sucrose I wouldn't expect to see excessive counts, so are there other ingredients in which its reasonable to expect a high incoming micro loading?

I think there is a need to review raw materials to get an estimate of what sort of levels you're actually realistically likely to be starting with, and if these look reasonable you can then consider moving on to doing a validation project with trials, analysis etc.

 

Just out of curiosity, given that you've got facilities for pasteurisation, is there a specific reason you're not using it for the squash?
 

[Anna21]

Hi! Thank you! Yes I understand that it is a bit of a yes/no/maybe game - and all way I will actually be able to be certain the level of preservation is enough is by performing the necessary tests. I was under the impression that the Fruit concentrate we add will have a fairly high microbial load, however I checked the COA's, and they are all clean. 

 

I received the results back of the squash, and it has a count of less than 10 cfu/ml in both the total plate count and Yeasts and molds, making me believe the level of preservation will be sufficient, as the microbial load isn't very high.

I am performing the necessary shelf life tests, and will have them tested after this again.

We do not pasteurize this batch so as to save time in the production process. Are all squashes generally pasteurized these days? How about cordials which have no fruit content?

 

Thank you so much for your advice! 

Unfortunately I think the answer to your queries is "maybe"...

Generally I wouldn't treat preservatives as a kill step in this application, but they will provide some degree of reduction in micro count. It is unlikely to achieve the full 5+ log kill you'd get from pasteurisation, but that isn't necessarily a problem.

 

In principle those preservatives should generally be able to achieve sufficient microbiological stability for that period of time, but this is of course dependent on the starting count.

You say you're expecting "fairly high" counts - what sort of figures are you envisaging?
Do you have raw material micro specs/results for your incoming products too?

As you're making a squash I'd guess that the juice component is a concentrate, and you really should see particularly elevated levels of spoilage organisms in this type of raw material - even if its not pasteurised there is usually some level of micro reduction from the evaporation stage(s), and I definitely know of processors who've validated this for 5-log kill in its own right.

Similarly if you're using a liquid sucrose I wouldn't expect to see excessive counts, so are there other ingredients in which its reasonable to expect a high incoming micro loading?

I think there is a need to review raw materials to get an estimate of what sort of levels you're actually realistically likely to be starting with, and if these look reasonable you can then consider moving on to doing a validation project with trials, analysis etc.

 

Just out of curiosity, given that you've got facilities for pasteurisation, is there a specific reason you're not using it for the squash?
 

[pHruit]

At <10 cfu/ml you should have no problem, so the next stage is perhaps to review the raw material specs to get a general idea as to how repeatable this will be on an ongoing basis.

 

As a very broad generalisation I'd expect a juice concentrate to have a spec of <1000 cfu/ml for TVC, and perhaps <100 cfu/ml for yeasts/moulds, possibly a little bit higher. Anything significantly above this would jump out as unusual so I'd want to know more about how it was processed and why the levels were relatively high.

 

As for processing, I'm not sure there is a typical approach - we see in-bottle pasteurised, hot filled, filtered / clean filled, aseptic, preserved/clean filled etc etc.  

It certainly can be and is done without pasteurisation, but if I had access to a pasteurisation stage and it didn't adversely affect the product, which it probably won't for a squash, then I'd use it. But then I'm a little bit risk-averse and have spent a sizeable proportion of my working life in a position where I regularly get to see what happens when drinks products go wrong...