Based on research I did in my PhD potassium sorbate is the most common potassium based additive. In fact, it accounted for almost 50% of all potassium additives in the USDA’s Branded Foods Product Database.
But, with so many different potassium additives approved for use in Canada and the USA, it is important for us and our patients to know if all additives are problematic. Because one thing we want to avoid is telling our patients to avoid foods that they can safely eat.
So what’s the scoop on potassium sorbate? Let’s dig in.
Not all potassium additives appear to be associated with increased potassium content
Based on potassium content reporting in the USDA’s Branded Foods Product Database, not all potassium additives appear to be associated with increases in potassium. Though, I worry about the accuracy of potassium reporting (read more about that here).
So, if I don’t trust the potassium listed on the label, the next best thing is to look at the research.
Bring in the three articles I am looking at today. A variety of foods were studied to determined how much potassium sorbate was added to them.
References for this post:
What is potassium sorbate used for, where is it used and how much is allowed?
In Canada potassium sorbate is a permitted preservative. Potassium sorbate is 26% by weight potassium. A variety of foods can have added potassium sorbate. The amount that can be added is specific to the food.
Limit | Foods |
Up to 500ppm | Cider, Wine, Honey Wine |
Up to 1000ppm | Oyster-flavoured sauce, Margarine, Jam, Jelly, Marmalade, Pickles, Relish, Ketchup, Relish, Tomato paste, Tomato pulp, Tomato purees, Mincemeat, Concentrated frozen juice or Juices, Cold-processed smoked and salted fish paste or smoked or salted dried fish, Meat and meat by-products, Unstandardized food*, Bread, |
Up to 3000ppm | Processed cheese products, cheddar cheese, cold-pack cheese food, cream cheese, cream cheese spread |
Up to 3500ppm | Cakes, croissants, Danishes and muffins, Salad Dressings |
Up to 5000ppm | Roti, Soft flour tortillas |
* Disclaimer: I have no idea what unstandardized food is. That is just what it is says in the regulations.
What is ppm?
PPM stands for parts per million. One ppm = 1mg per liter of liquids or per kilogram of solids.
Let’s look at two examples.
For most products, the potassium sorbate limit is 1000ppm. This means that for 1kg of (for example pickles), there can be up to 1000mg of potassium sorbate. From this, 26% will be from potassium. So there could be up to 260mg of potassium per 1kg of pickles. If your patient eats 100g of pickles, then this could mean that the pickles contributes up to 26mg of potassium to their daily intake. That’s pretty low.
At the upper end is Roti. For Roti, the potassium sorbate limit is 5000ppm. This means that for 1kg of roti, there could be up to 5000mg of potassium sorbate. Of this 26% will be from potassium. So there could be 1300mg of potassium per 1kg of roti. According to the Canadian nutrient file , 1 piece of roti is 68g. So if your patient was having 1 standard roti at a meal, then this could mean that the roti contains as much as 88mg of potassium from potassium sorbate.
How much potassium sorbate is being added to foods?
Based on the results of the first two studies, the mean amount of potassium sorbate being added to condiments is 158mg per 1kg. Of this, 41mg per 1kg would be potassium. For pickles the mean potassium sorbate content was 0.31mg per kg. Of this, 0.08mg per 1kg would be potassium.
For the condiment study, the means potassium sorbate content varied quite a bit, even between similar products. Below are some of the results. I picked out products that are consumed with some frequency by my Canadian patients. Of note, both Iran and Canada have similar limits on the amount of potassium sorbate that can be added to these products.
Food Item | Mean Potassium Sorbate Content | Mean Potassium Only Content (total potassium sorbate * 0.26) |
Regular Fat Mayonnaise (7 products) | <measurable to 227mg/kg | Up to 59mg/kg |
Low Fat Mayonnaise (13 products) | <measurable to 460mg/kg | Up to 120mg/kg |
Reduced Fat Mayonnaise (10 products) | <measurable to 383mg/kg | Up to 100mg/kg |
Thousand Island Dressing (3 products) | 14mg/kg to 345mg/kg | 3 to 90mg/kg |
French Dressing | <measurable to 95mg/kg | Up to 25mg/kg |
Despite the variability, given that these measurements are per kg of condiment and typical intake of condiments is likely closes to a few tablespoons per sandwich or salad, the total amount of potassium added from potassium sorbate is likely clinically insignificant.
What about bread products?
This is an area that I am less certain about. The upper limit for added potassium sorbate in bread products is much higher than the upper limit for condiments. Additionally, people tend to eat more bread products than condiments, so there is a higher likelihood of the potassium starting to add up.
In this study, the mean potassium sorbate for cake and bread products was between 56-128mg/kg. Which I would consider pretty low. However, I am not sure if these results are applicable to the Canadian market. The authors reports that the upper limit of allowable potassium sorbate in bread products product in Iran is 500mg/kg. This makes the Canadian limit 10 times higher.
Take Aways
Potassium sorbate is a common preservative. A variety of foods have added potassium sorbate. The amount of potassium sorbate that is allowed to be added to most foods is relatively low. Suggesting, that in most cases potassium sorbate is unlikely to be an additive of concern.
However, the amount of potassium sorbate allowed in bread products is higher and people tend to eat larger amounts of these foods, so if potassium is an issue, it may be worthwhile to do some label reading to see if the product contains potassium sorbate.
That being said, to prevent any unnecessary dietary restrictions for our patients, I recommend investigating this on a case by case basis. For now, I still recommend leaving potassium sorbate off the list of potassium additives of concern, at least until we know more!
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