Panera Know-No List Part IV: Preservatives

From medieval salt preservation to witch trials induced by ergot in moldy bread, to Twinkies that would reportedly survive a nuclear blast, food preservation has come a very long way.

In May 2015, Panera published a list of ingredients that would be removed from their food. In the same month, other companies like General Mills and Nestle made similar announcements, and more will surely follow suit. The food industry is amidst a curious and wonderful revolution, but the saddest part about these announcements is the missed opportunity to celebrate the food science.

Announcing the removal ingredients from a product can attach an stigma to those ingredients, especially if the justification isn’t fully explored. James Cameron reportedly waited for cinema technology to advance before making Avatar, so why can’t food companies talk about how the swaps they’re promising weren’t technically feasible until now?

In this post, we continue deconstructing Panera’s No No list. [For Part I, Overall Response, Part II, Sweeteners, and Part III, Color/Flavor Enhancers, see previous posts]. For each ingredient, you’ll find a brief explanation of its purpose, safety concerns if any, and whether a natural counterpart can perform as well or better.

Part IV of V –

*These ingredient assessments below are part of a collaborative effort, and I thank all who have helped me compile this information. See “FOR MORE INFO” for resources. Contact me on Twitter @GreenEyedGuide for the opportunity to join them in completing and improving this project.

[The official Panera No No List is available here; replicated below.] Ingredients discussed in this post are red.



Benzoic Acid, Potassium Benzoate, Sodium Benzoate

  • PURPOSE: Prevents growth of microorganisms like yeast and mold; used for preservation of sour food pH 4 and lower, often used with other preservatives especially at low pH (acidic food). Used in carbonated beverages, fruit salads, jellies, margarine. Sodium benzoate is added to deli-style meat, hotdogs, and poultry products to inhibit microbial growth of the lethal bacteria L. monocytogenes
  • BENEFIT OVER NATURAL: Benzoic acid occurs naturally in cranberries, prunes, plums, cinnamon, ripe cloves, and most berries; “Replacing proven preservatives like sodium benzoate with a natural alternative needs to be very carefully researched and tested before it can be implemented, especially where there are safety concerns. One approach that might make this easier is to use natural antimicrobials in combination with one another or with other technologies in a multi-hurdle preservation system. For example, nisin in combination with carvacrol has been shown to be more effective than nisin alone.” –Food Safety Watch
  • SAFETY NOTES: Consumers can ingest up to 5mg per kg of body weight of benzoic acid and its salts including benzyl alcohol and related benzyl derivatives used as flavorings, according to European Commission – Scientific Committee on Food. There are safety concerns suspected but unconfirmed for benene formation from benzoic acid with ascorbic acid. However, this risk “cannot be reliably assessed on basis of data available” BfR Expert Opinion
  • FOR MORE INFO:  The Natural Alternative: antimicrobial compounds derived from nature as an alternative to synthetic preservatives in foodFood Safety Watch

Butylated Hydroxyanisole (BHA), Butylated Hydroxytoluene (BHT), Ethoxyquin, Tertiary Butylhydroquinone (TBHQ)

  • PURPOSE: Prevents oxidation and delays rancidity in foods that contain oil; TBHQ is a synthetic antioxidant; fat-soluble antioxidants like BHA, BHT and tocohperols are suitable for oil/water emulsions but TBHQ is very active in fats and oils; FOUND IN butter, shortening, pastries, breads, crackers, potato chips, dehydrated potatoes, dried fruit
  • BENEFIT OVER NATURAL: TBHQ is especially effective for highly unsaturated vegetable oils and many animal fats and carries advantage over other previously approved antioxidants in its ability to extend the storage stability of vegetable oils. Despite the evidence that BHA may be harmless, some may elect not to eat foods that contain it, in part because it’s not worth the risk that BHA may have unknown deleterious effects in humans, and in part because there’s a very effective alternative: vitamin E.
  • SAFETY NOTES: TBHQ is intended to be used at a level of up to 200 mg/kg fat or oil, so assuming all fats consumed have TBHQ at 200mg/kg; Using estimated intakes for infants, children, and adults based on food consumption databanks from multiple European countries, the exposure levels of TBHQ for adults and children who are high fat eaters does not exceed the ADI. With BHA and BHT, small doses have not been associated with side-effects. The dosage makes the difference.
  • FOR MORE INFO: This short article from Live Science article on BHA and BHA has good information about some of the suspected safety concerns and the natural alternatives. It’s a good read!

Calcium Sorbate, Potassium Sorbate

  • PURPOSE: Sorbic acid and sorbate salts such as calcium sorbate, potassium sorbate, and sodium sorbate are anti-microbial preservatives; they prevent the growth of fungi and yeasts. They are not effective against bacteria. The sorbate salts work best at pH values below 6.5 (acid and slightly acid foods). FOUND IN: cheese, frozen pizza, bread, fountain sodas, deli salads, jelly, baked goods
  • SAFETY NOTES: The CPSI puts these in the “Safe” column of their Chemical Cuisine list of food additives
  • FOR MORE INFO:  See the article on Potassium Sorbate by Food Construed references and resources on the Sorbic Acid article from Be Food Smart

EDTA (Calcium Disodium EDTA/Disodium Dihydrogen EDTA)
  • PURPOSE: Chelating agent, meaning it binds metal ions to limit their deleterious effects; EDTA stabilizes food color, aroma, texture, inhibits oxidation of fats, oils. COMMONLY USED IN: mayonnaise, canned mushrooms and beans
  • BENEFIT OVER NATURAL: There aren’t many natural chelating agents, but DuPont recently launched a natural alternative from plant extracts. The challenge with finding natural alternatives is that shelf-life normally suffers. See Food Navigator’s article on DuPont’s natural EDTA alternative
  • SAFETY NOTES: Some sources say EDTA “robs the body of nutrients” but EDTA is safe to consume up to 3 grams per day *AMOUNTS USED IN FOOD are in the milligram per kilogram or parts-per-million range. CPSI puts this in the “Safe” column.
    ***FUN FACT: EDTA is actually used to treat people with heavy metal poisoning because EDTA can grab the heavy metals and escort them out of the body. “While this is great for someone with too many metals, a high dose of EDTA administered to someone in good health could have toxic effects. Our bodies need certain metals to complete complex cellular reactions. And don’t forget that hemoglobin in our blood uses iron. The amount of EDTA used in food products, then, has been set to be far below what would be a toxic level.” – Eating Real Food on EDTA
  • FOR MORE INFO: Good overview by Food Construed

Parabens (all)

  • PURPOSE: Some types of parabens are used in cosmetics; other types are used as food additives. For food products, parabens are added as preservatives to prevent the products from decomposing as a result of microbial growth or undesirable chemical changes. Parabens work better against yeast than bacteria. FOUND IN: Baked goods, fillings for baked goods, fruit juices, marmalades, syrups, preserves, olives. 
  • BENEFIT OVER NATURAL: Some parabens are naturally occurring. Paraben alternatives include other antimicrobial agents. See “The Natural Alternative: antimicrobial compounds derived from nature as an alternative to synthetic preservatives in food”Food Safety Watch
  • SAFETY NOTES:  The European Food Safety Authority (ESFA) concluded that acceptable daily intake is 0-10 mg/kg body weight per day for methyl and ethyl parabens and their sodium salts. (Reported by Food Navigator). From April/May ChemMatters Teacher’s Guides from American Chemical Society “A study published in 2004 (Darbre, in the Journal of Applied Toxicology) detected parabens in breast tumors. The study also discussed this information in the context of the weak estrogen-like properties of parabens and the influence of estrogen on breast cancer. However, the study left several questions unanswered. For example, the study did not show that parabens cause cancer, or that they are harmful in any way, and the study did not look at possible paraben levels in normal tissue.”
  • FOR MORE INFO: See the review by Be Food Smart

Potassium Bisulfate, Sodium Metabisulfite, Sulfites, Sulfur Dioxide

  • PURPOSE: Sulfiting agents are commonly used to preserve the color of foods, such as dried fruits and vegetables, and to inhibit the growth of microorganisms in fermented foods, like wine. Sulfites can also be found in beer, some fruit drinks, shrimp and some prepared foods. – From Food Insight: Food Allergy Myths and Realities
  • BENEFIT OVER NATURAL: There are other ways to control oxidation its subsequent effects on color in food, that is to control the amount of oxygen the product is exposed to. With wine, going sulfite-free is quite the challenge, as discussed in this article by Eating Well: Eating Well – The Hype about Sulfites
  • SAFETY NOTES: This is another hot topic in the industry, as there are passionate people on both sides of the argument.
    (1) Use of sulfites used to be unregulated and high, unmonitored usage in restaurants is attributed to multiple deaths in the 1980s. Sulfite content is now carefully monitored and labeled, and CSPI puts this in the “Certain People Should Avoid Category”. The safety-story behind sulfites is interesting. CSPI recaps it well.
    (2) Although sulfites are safe for the majority of people, some people may have a reaction. For this reason, the FDA requires that when sulfites are added to foods in greater than 10 parts/million (or, 10 sulfite molecules per million molecules) they must be indicated on the label.
    (3) The “No Observed Adverse Effect Level” of SO2 (sulfur dioxide) is 30-100mg per kg body weight per day.
    ***FUN-FACT: In the body, sulf-I-te is rapidly converted to sulf-A-te, unless you have the rare metabolic disorder of being deficient in the enzyme responsible for this conversion. SulfIte and Vitamin B1 (thiamine) don’t play well together and sulfIte’s destruction of thiamine is why use of sulfiting agents is prohibited by regulation in foods known to be major sources of the vitamin.
  • FOR MORE INFO: Check out the CSPI and Food Insight links above

Potassium Lactate, Sodium Lactate

  • PURPOSE: Lactic acid is a byproduct of the curdling of milk, commonly found in dairy products such as yogurt, kombucha and some cottage cheeses. Potassium lactate and sodium lactate come from lactic acid, and can preserve foods by making the conditions too acidic for bacteria (especially Listeria) to grow. Both sodium lactate and potassium lactate are commonly used in cooked/cured meats, but potassium lactate may be used if the food’s sodium content is a concern.
  • SAFETY NOTES: Sodium and potassium lactate are approved for use in the US, the EU, Australia and New Zealand, according to Noshly Health Canada approved them stating “no safety concerns“. Neither sodium lactate nor potassium lactate made the CSPI Chemical Cuisine list.
  • FOR MORE INFO: See this great overview by Food Construed

Propionates (Calcium, Sodium)

  • PURPOSE: Calcium propionate (along with propionic acid and sodium propionate) is used as a preservative with antimicrobial activity. Propionates work mostly against mold. They are used mostly in bread and other baked goods, but they also occur naturally in butter and some types of cheese. In bakery systems with high pH, use of preservatives such as Sorbic Acid and Calcium Propionate may be completely ineffective.
  • BENEFIT OVER NATURAL: Propionates work mostly against mold, not as well against yeast, but they can still prevent yeast in bread from performing optimally, which may negatively affect bread volume, according to Maxx Performance.
  • SAFETY NOTES: This is another hot topic in the industry, as there are passionate people on both sides of the argument. Certain organizations advocate AGAINST the use of propionates and the truth is that some people may be sensitive to them, but multiple studies have confirmed the safety of propionates.
    (1) The European Food Safety Authority Panel on Food Additives and Nutrient Sources added to food (ANS) reviewed propionates and found, “Overall, taking into account of all these considerations including the natural occurrence in food, the Panel concluded that for food as consumed, there would not be a safety concern from the maximum concentrations of propionic acid – propionates [propionic acid (E 280), sodium propionate (E 281), calcium propionate (E 282) and potassium propionate (E 283)] at their currently authorised uses and use levels as food additives.”
    (2) Every body responds to food differently, so it’s tempting but misleading to use one person’s experience as evidence of safety. If you suspect you may be sensitive to propionates, you can read about some of the side effects by LiveStrong
    (3) Proprionates are on the CSPI Chemical Cuisine list under the “Safe” category
  • FOR MORE INFO:  This article by covers all the important aspects of this additive — HIGHLY INFORMATIVE, on About Health

Propyl Gallate

  • PURPOSE: Preservative to prevent rancidity in fat and oils, often used with BHT and BHA (see above)
  • BENEFIT OVER NATURAL: Other methods to control oxidation, spoilage, and rancidity in fats and oils include limiting the light and air the oils are exposed to, and using other antioxidants like Vitamin E. See the entry on BHT and BHA above.
  • SAFETY NOTES: There needs to be some more studies done with this one, as its safety is a bit questionable. Granted no evidence that something exists isn’t evidence that something does not exist. Basically, we haven’t really proven that PG is safe but we haven’t proven that it’s not safe yet, either.

    (1) The CSPI puts this one in the “Avoid” category
    (2) The FDA Select Committee on GRAS Substances (SCOGS) Opinion cites the findings of the FAO/WHO Expert committee on Food Additives, “There is no evidence in the available information on propyl gallate that demonstrates it to be a hazard to the public when used at levels that are now current or that might reasonably be expected in the future.” The EFSA Panel on Food Additives and Nutrient Sources added to food (ANS) echoes this statement in “Scientific Opinion on the re-evaluation of propyl gallate (E 310) as a food additive
    (3) The Environmental Working Group phrased it best in their review of food additives that have GRAS (generally recognized as safe) staus, “These findings do not establish a causal link between propyl gallate and cancer, but they raise important questions about whether this chemical should be considered safe.”

  • FOR MORE INFO: See any of the links above.

Sodium Diacetate

  • PURPOSE: Sodium diacetate is a mixture of sodium acetate and acetic acid; Acetic acid is a natural acid present in most fruits, while sodium acetate is commercially produced by bacterial fermentation of sugar, molasses or alcohol or by chemical synthesis from acetealdehyde. It acts as a preservative and is normally used in seasonings
  • BENEFIT OVER NATURAL: As a matter of fact, vinegar is a rising star as a natural preservative. Vinegar is primarily acetic acid but diluted acetic acid cannot be labeled as vinegar. While sodium diacetate is a colorless solid with minimal flavor impact, vinegar may change the flavor of the product and can be corrosive to food manufacturing equipment.
  • SAFETY NOTES: Sodium diacetate is not on the CSPI Chemical Cuisine list but acetic acid is under the “Safe” category. may also be used to inhibit Listeria (Food Insight).
  • FOR MORE INFO: See “Vinegars for Food Processing” from UL Prospector Knowledge Center

Sodium Erythorbate

  • PURPOSE: This additive is a molecule ascorbic acid (vitamin C) with a slightly different spatial orientation of the pieces (a stereoisomer in chem-speak). It has no nutritional value. It increases the rate at which nitrite turns into to nitric oxide. This leads to a faster cure and helps to retain the pink coloring.
  • SAFETY NOTES: The CSPI puts this in the “Safe” category
  • FOR MORE INFO: See Food-Info

Stannous Chloride


Companies should not be criticized for making clean-label commitments like this. However, consumers would benefit much more from moves like this if the companies are more transparent about WHY each ingredient is coming out, and what that ingredient was doing in the food in the first place. If you believe in this type of transparency, this type of consumer awareness, help me share this information.


Food Business News – Consumers fear some ingredients more than pathogens

Here & NowDoes Removing Artificial Ingredients Mean Healthier Food?

Science Meets FoodRenouncing Pronounce-ability



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