Testing for levels of Nitrates / Nitrites after slow curing.

[reddal]

Hi,

I've been making Chorizo using cure #2 (ie inc nitrates) and some customers have been concerned about Nitrates in the product. I've explained that most of the worry about nitrates is myth and fear mongering - and that most if not all of the nitrates are consumed during the curing process.

However I'd like to be able to be sure of that - so I'm planning on sending a sample of my next batch to a lab to get it tested for levels of nitrates and nitrites. Hopefully the result will be that there are only very small levels in the final product. Does anyone have any experience of what to expect here?

If there are Nitrates remaining in more than trace amounts - I will try to incorporate an antioxidant into my recipe to try to make sure the levels are reduced in the final product. I've read threads like this one about the options of using sodium erythorbate vs sodium ascorbate vs ascorbic acid (vitamin c). However my customers would likely get freaked out by the first two on the ingredients list! If I could achieve the same effect using pure vitamin C (like this) then it wouldn't stress anyone because I could call it Vitamin C on the label. However then I understand I'd have to be careful about not letting it mix too much with the cure.

My recipe involves adding the cure, spices etc before grinding the meat, and then adding wine once the result is mixing. If I added Vitamin C to the wine before adding to the mix would that avoid the problems of ascorbic acid interacting badly with the cure do you think?

Thanks in advance for any advice.

- reddal

[redzed]

Hi reddal, I commend you for taking your customers concerns into account and also wanting to have an elevated understanding of the process. I am very much interested in the amount of residual nitrates/nitrites in your products. Please be sure to post the results here. Technical publications tell us that the amount will be between 10 and 20% of the ingoing amount. Sodium erythorbate is used in very small amounts and is in fact a form of vitamin C. It is a cure accelerant, an anti-oxidant, helps with the bind and keeps that nice red colour longer in the sausage. As far as the ascorbic acid, you should be fine with adding it the following day, with wine or not. I believe that the recommendation is not to add it at the same time as the cure, but rather to distribute the cure into the meat block, wait an hour and then add it.

Send me a pm with your email address and I'll email you some technical material.

[reddal]

Thanks.

In this thread I note the recommended dosage of Ascorbic acid is 0.05% for 'normal cure dosage'.

I'm using 0.25% of cure #2 (6.25% sodium nitrite 4% Potassium nitrate and 89.75% salt). I think this is a normal cure dosage?

Given this is the first time I've used Ascorbic acid - maybe I'll only add 0.025% (half the amount recommended above) this time and see if it makes any difference to the nitrate/nitrites levels at the end? Or should I just stick to the 0.05%?

Do you think the addition of ascorbic acid will affect the flavour / texture of the product at all? ie if it accelerates the curing process will that affect the end result?

thanks - reddal

[redzed]

Hi reddal,
From what I have learned is that Sodium Erythorbate is preferred over Sodium Ascorbate because it is more stable and less expensive. And while .05% is the recommended amount to use as a cure accelerant and anti-oxidant, larger amounts can be used if it's purpose is to acidify the meat. Somewhere I read that you are good up to .075% before the dosage starts to affect the pH. Below is a quote from Joseph G. Sebranek "Basic Curing Ingredients" in Rodrigo Tarté, Editor, Ingredients in Meat Products: Properties, Functionality and Applications

Reductants
Properties
Ascorbic acid and erythorbic acid are water soluble organic acids with significant
antioxidant properties. Both exist as white to pale yellow crystals that are relatively
stable. l -Ascorbic acid has vitamin C activity and, consequently, provides this biological
property in addition to reductant and antioxidant properties. It may be identified
on ingredient statements as vitamin C. Erythorbic acid is the molecular
stereoisomer (mirror image) of ascorbic acid, and while its chemical properties are
the same as for ascorbic acid, it does not provide significant biological activity.
A 1% solution of these compounds has a pH of 2.8-3.1 and, consequently, direct
contact of the acid forms of these compounds with nitrite can result in extremely
fast reduction and excessive loss of nitric oxide from the curing mixture.
Sodium ascorbate and sodium erythorbate are sodium salts of the acids and are
the most common forms of the reductants used in commercial meat curing. The
chemical properties and reductant activity of the salts are very similar to those of
the acids. However, an aqueous solution of sodium ascorbate or erythorbate will be
pH 5.5-8.0 and, while contact with nitrite will result in nitric oxide production, the
reaction will be slower than if the acid forms of the reductants were used.
Functions
The reductants provide for accelerated production of nitric oxide from nitrite, probably
by serving as one-half of the oxidation-reduction pairing with N 2 O 3 formed
from nitrite, as discussed earlier. Because acidic conditions control the amount of
the N 2 O 3 intermediate formed, it is easy to understand the major interactive role of
acidulants and reductants in meat curing. The reductants are also very effective for
reducing oxidized metmyoglobin to reduced myoglobin (Shahidi & Samaranayaka,
2004) , a function that facilitates cured color development, particularly in cases
where addition of nitrite oxidizes the meat pigment. Ascorbate and erythorbate are
extremely effective for maintaining fresh meat color as bright red oxymyoglobin
(Manu-Tawiah, Amman, Sebranek, & Molins, 1991) , but are not permitted to be
used for this purpose in the United States. However, the reductants are allowed to
be used in a 10% solution to spray the surfaces of cured meat products prior to
packaging to improve color stability, providing that no significant additional moisture
is added to the product (USDA-FSIS, 1995) .
Regulations
Ascorbic acid and erythorbic acid, alone and in combination, may be added to
cured meat or poultry (injected, immersed, comminuted, or dried) at a maximum
concentration of 469 ppm, based on the green weight of the meat block. Sodium
ascorbate and sodium erythorbate are limited to 547 ppm. Citric acid or sodium
citrate may be used to replace up to half of any one of the above reductants. While
the above regulations apply to all cured meats, bacon is an exception. For injected
bacon, sodium ascorbate or sodium erythorbate is required (not optional) at
550 ppm (USDA-FSIS, 1995) .

[reddal]

Hi,

I got the lab report back of the test for nitrate/nitrite levels in my chorizo.

I sent them three samples to test :

• A fully mature chorizo sample, about 7 weeks since fermentation, made without any anti-oxidant
  A nearly mature chorizo sample, about 5 weeks since fermentation, made without any anti-oxidant
  A not yet ready chorizo sample, about 4 weeks since fermentation, made with addition of ascorbic acid.

I was interested to see if the different level of maturity affected the final nitrate/nitrite level and whether the addition of ascorbic acid helped to reduce the levels.

The results for all three were identical as follows :



i.e. there were zero amounts of nitrate/nitrites detected. If any were present they were below the sensitivity of the test (5mg/kg and 1mg/kg).

Working out the amount of nitrates/nitrites that originally went into the raw mix - from the % ingredients of cure#2 I'm using and the 0.25% rate of cure#2, I think the input mix had about 100 mg/kg of nitrate and 150 mg/kg of nitrite - so those numbers being reduced to <5 and <1 means that pretty much all of the nitrate/nitrites in the input mix have gone by the time the final product is ready.

Its also clear that there were no nitrates/nitrites in the sample that was not fully dried yet - so the process is quick.

Adding antioxidants doesn't seem strictly necessary to reduce nitrates/nitrites - however it doesn't do any harm that I can tell - and may add an extra level of confidence. When added (carefully) in the form of Ascorbic acid (pure Vitamin C) there is no marketing downside to this either - therefore I will continue to add this.

Summary - all good news - nitrates/nitrites aren't a big deal anyway in my opinion - but for those customers that worry about them I can assure them with evidence that there are no detectable amounts of nitrates/nitrites in my chorizo .

- reddal

p.s. for those interested - here is the description of the test method used from the lab report:

[Butterbean]

Thanks for sharing your results. They are as I expected but my hat's off to you for going the extra mile to confirm things.

I have something I'll share in another thread which goes along these lines which you might find interesting and possibly even helpful when you try to educate your customers and others.

[StefanS]

Very interesting subject and results. I would like to make similar tests here in USA, does anybody know where or with whom I can talk about? I'm specifically interested in knowing nitrate/nitrite levels after Equilibrium cure and brine method. Or maybe somewhere are already tests done but I can not find results?

[Bob K]

Do a search for food testing labs, there are a lot of them some fairly local. https://www.alliantfoodsafety.com/

https://www.google.com/search?source=hp ... :1,lf_ui:2