Safe Levels of Sodium Metabisulfite

Hi All,

 

Folks, I heed your help, please.

We are fruit and vegetable processing place and we are about to launch a new product which is peeled potatoes. It will come in both 5-gallon and 20-gallon containers filled with Sodium Metabisulfite solution to preserve the potatoes. I have instructions on mixing the right concentration. I don't feel comfortable going just by mixing formula. I need test strips or test kit to measure the concentration level. I don't even know what are safe levels for Sudium Metabisulfite for peeled potatoes. Please, if someone has expertise in that field, advise me on what I should do.

 

Many thanks,

 

Ostap

Dear oromaniv,

 

Sounds like a product which might be of considerable interest to the USFDA. :smile:

 

Is this for retail or ?

 

Does it have a specification ? First item of desirability.

 

i presume you are aware that sulphites are associated with health aspects, eg "allergenic" features as discussed in another recent thread.

 

Rgds / Charles.C

Oromaniv,

 

Glad to see someone else with similar issues to I.  I am in Canada and do the exact same thing as you, whole peeled potatoes in sodium Metabisulfite.  Currently in Canada there is no stated standard.  On the advice of some professionals we are following guidelines in similar countries, ie Australia.  I was given some information stating acceptable levels anywhere from 200PPM to 1000 PPM.  There are some test strips available that tests the sodium metabisulfite level in the water, Quantofix is the brand of test strip we use. 

 

Hope some of that info is useful to you.

nlbrenn

Oromaniv,

 

Glad to see someone else with similar issues to I.  I am in Canada and do the exact same thing as you, whole peeled potatoes in sodium Metabisulfite.  Currently in Canada there is no stated standard.  On the advice of some professionals we are following guidelines in similar countries, ie Australia.  I was given some information stating acceptable levels anywhere from 200PPM to 1000 PPM.  There are some test strips available that tests the sodium metabisulfite level in the water, Quantofix is the brand of test strip we use. 

 

Hope some of that info is useful to you.

nlbrenn

 

Dear nlbrenn,

 

One might have thought that the sulphite level in the finished product was more relevant ?

 

Or is it assumed that the SO2 "disappears" when used by the consumer ? This would presumably relate to the recommended use which is so far unmentioned, eg RTE ?

 

Rgds / Charles.C

Hi Charles,

 

Yes I would assume that it has everything to do use.  All of our products are processed further as we are a ready to cook plant and we can never seem to find recommendations on ready to cook products.  We use SO2 on uncooked potatoes and potatoes are not generally eaten raw, at least in my experience. I think that is why there is such a large range. The Australian guideline I referred to earlier states potatoes (hot chips and French fries) 200ppm and potatoes for manufacturing 1000ppm. 

Hi Charles,

 

 The Australian guideline I referred to earlier states potatoes (hot chips and French fries) 200ppm and potatoes for manufacturing 1000ppm. 

Dear nlbrenn,

 

Thks yr input.  A few comments -

 

I presume above means 1000 ppm in raw potatoes after dipping / packing /ready for sale. And 200 ppm in "hot chips / French fries" after pack / ready for sale.

i presume "hot chips' is Australian slang. global meaning AFAIK unknown. :smile:

It is unclear whether the "French fries" are semi-cooked sold frozen, ready -to-eat (microwaveable?) or ?. Differences not insignificant.

 

Even if no legislation exists (which seems unlikely if RTE), IMO -

 

1000ppm is astronomical.

200ppm in a retail rte product seems extremely high. And not low in a retail non-rte product either.

 

Rgds / Charles.C

Dear nlbrenn,

i presume "hot chips' is Australian slang. global meaning AFAIK unknown. :smile:

 

:off_topic: In America it means attractive highway police that ride cool motorcycles.

Charles.C, that's a great point the levels in finished product. So what would be the way to measure them? I assume I would need to dip in different concentrations and send out to the lab to find out, right? We sell peeled potatoes as non-rte product to food service, so it is intended to be cooked before consumption. I didn't find any US legislation regarding acceptable limits except if product contains >10 ppm it must be declared on the label. Also FDA prohibited the use of sulfites on fruits and vegetables intended to be served raw or presented fresh to the public. The only exception is sulfite use on minimally processed potatoes sliced or shredded for frying where sulfite use is still permitted (although FDA has a long-standing, though never finalized, proposal to ban that use also). I think that's a matter of time when we stop using sulfites as preservatives. Ostap

Dear oromaniv,

 

Something like this gives an approximate idea -

 

http://www.indigo.co...ml#.U2qDxnJn1kg

 

I have seem people simply touch the product but making up a blend seems a more representative procedure. Need to check the instructions.

 

A more accurate measurement needs a lab. with a standard procedure. Readily available.

 

Rgds / Charles.C

 

PS- another variation here for solid product such as shrimp (procedure given at bottom link) -

 

http://www.neogen.co...st_Kit_Cat=207b

The only exception is sulfite use on minimally processed potatoes sliced or shredded for frying where sulfite use is still permitted (although FDA has a long-standing, though never finalized, proposal to ban that use also). I think that's a matter of time when we stop using sulfites as preservatives. Ostap

 

The threat has been there for a long time, but you have a lot of potato industries with a lot of clout.  Sulphites work well for potatoes, since potatoes are rarely if ever eaten raw, and are going to be cooked, they have been relatively safe.  Sulphites are also cheap.  Have seen many companies try to come up with alternatives, but  the effectiveness vs. the cost were always an issue.  

Dear All,

 

Happened to notice this comment regarding sulphites / potatoes. Food for thought.

 

Sulfites are also prohibited from certain uses in the U.S. Sulfites may not be used in products such as meats that serve as a good source of vitamin B₁ because sulfites can scavenge that vitamin from foods. In 1986, following the identification of numerous cases of sulfite-induced asthma occurring on ingestion of green or fruit salads treated with sulfites, FDA prohibited the use of sulfites on fruits and vegetables intended to be served raw or presented fresh to the public (Fed. Regist. 51:25021-25026, 1986). The only exception is sulfite use on minimally processed potatoes sliced or shredded for frying where sulfite use is still permitted (although FDA has a long-standing, though never finalized, proposal to ban that use also). Sulfite use as a fungicide during the shipment of fresh table grapes is regulated by the U.S. Environmental Protection Agency, but the concentration of SO₂ residues on the table grapes as consumed must be <10 ppm total SO₂.

 

http://farrp.unl.edu/sulfites-usa

Nlbrenn, What shelf life results are u you getting with concentrations you mentioned above? Thanks Charles.C, Good job finding the Allergen Research Program link, I used it in my previous post. Regards

we process potatoes for hospitality industry in New Zealand. we dip the potatoes in a sodium met solution @ 7g per litre of water and pass through a dip tank which takes 1 minute and 40 secs to get through. our lab tests show an SO2 level of <10ppm. the allowable residue of SO2 in New Zealand is a max of 200 ppm. hope this helps

:welcome: leighbre.   Good information. 

we process potatoes for hospitality industry in New Zealand. we dip the potatoes in a sodium met solution @ 7g per litre of water and pass through a dip tank which takes 1 minute and 40 secs to get through. our lab tests show an SO2 level of <10ppm. the allowable residue of SO2 in New Zealand is a max of 200 ppm. hope this helps

 

i would suggest you investigate the option of labelling yr product as Low-SO2, by NZ standards. Sounds worth promoting. The only process problem may be that <10ppm does not do anything ?

 

I hope that the typical NZ potato is rarely eaten  under-boiled/fried.

 

Charles.C

what the dipping does is stops the enzymic browning and gives you shelf life (up to 10 days) if stored at the correct temp (1 - 4 degrees)

what the dipping does is stops the enzymic browning and gives you shelf life (up to 10 days) if stored at the correct temp (1 - 4 degrees)

 

Dear leighbre,

 

Thks.

 

Is it anywhere validated that 10 ppm is sufficient for the prevention. I'm wondering why people would use 200 + ppm ? Just making sure ?

 

Rgds / Charles.C

we trialed different levels and found that the levels used were sufficient to stop the product browning and give us the shelf life we wanted. the least amount of chemical used to achieve the results the better cost effectivness and residue levels as low as possible

we trialed different levels and found that the levels used were sufficient to stop the product browning and give us the shelf life we wanted. the least amount of chemical used to achieve the results the better cost effectivness and residue levels as low as possible

 

Dear leighbre,

 

Thks.

 

i deduce that 200 ppm may give significantly longer shelf lives. Maybe explains a lot.

 

Rgds / Charles.C

Dear leighbre,

 

Thks.

 

i deduce that 200 ppm may give significantly longer shelf lives. Maybe explains a lot.

 

Rgds / Charles.C

 

Having participated in the some shelf life studies with varying levels of sodium metabisulfite--not necessarily.  What I found interesting is that low levels were sometimes not enough to prevent the browning and sometimes required more chemical to prevent it in the first place.  But amount of sulfite did not seem to impact the shelf life, however high levels sometimes impacted the hardness of potato in an unappealing way.  I was not there for the whole study so I can't tell you why; that is where it was going next.   But it was an interesting study. 

Hi everyone,

 

all the best of the season!

 

I am wanting to do an environmental swab for sulphites to validate the cleaning process post allergen clean. Does anyone know of an environmental swab kit? I have searched but can't seem to find one. I was hoping it would be the same as egg, dairy, mustard etc...

 

Thanks in advance for your reply.

 

James

Hi everyone,

 

all the best of the season!

 

I am wanting to do an environmental swab for sulphites to validate the cleaning process post allergen clean. Does anyone know of an environmental swab kit? I have searched but can't seem to find one. I was hoping it would be the same as egg, dairy, mustard etc...

 

Thanks in advance for your reply.

 

James

 

Hi James,

 

Why not use a sulphite test strip (readily available) to test the food  and surfaces ?

Hi Charles,

 

I checked Neogen and Romer labs and neither had a test strip that I could see. Would you be able to point me to a supplier of this test strip?

 

Thanks,

 

James

Hi Charles,

 

I checked Neogen and Romer labs and neither had a test strip that I could see. Would you be able to point me to a supplier of this test strip?

 

Thanks,

 

James

 

I would like to add that I did fond test strips but they all seem to be for testing liquids, I would like to swab environmental and get results to see what PPM is left on equipment post clean.

Hi James,

 

2 examples sulphite methodology -

 

neogen sulphite kit.pdf   227.16KB   35 downloads

indigo test strip.pdf   490.2KB   27 downloads

 

Unless you are using sulphites in yr process I would anticipate that the general environment will indicate negligible since IIRC simple sulphites are rather unstable to the atmosphere. Note that semi-quantitative test kits/strips typically have a detection limit of ca. 10ppm.

 

PS - Strange that Neogen expressed ignorance !