Clean Label Mold Inhibitors2019-03-27T10:06:25-07:00
Clean label mold inhibitors

Clean label mold inhibitors are the alternative to chemical preservatives that help inhibit mold growth and/or prolong the shelf life of food products.

Clean Label Mold Inhibitors

Also known as Natural Mold Inhibitors

What are Clean Label Mold Inhibitors?

Clean label mold inhibitors help inhibit mold growth and/or prolong the shelf life of food products. The United States Department of Agriculture (USDA) National Organic Program (NOP) regulates that anything labelled “organic” needs to be certified by USDA NOP.

According to the Code of Federal Regulations (Title 7 Part 205.105), to be sold or labeled as “organic”, the product must be produced without the use of synthetic substances and ingredients, nonagricultural substances used in or on processed products.1 But vaccines which is GRAS (generally recognized as safe) can be used in organic products.1


There are two main natural clean label inhibitors based on their different modes of action:2 by reducing dough pH and by disrupting molds cellular membrane and cellular processes.2 The amounts to use are given in Baker’s Percentage. During the winter months, when mold problems are not as likely to occur, use the lower end of the suggested ranges.

Category 1: Reduce dough pH

Vinegar: Vinegar is a dilute solution of acetic acid. Strength (or concentration) of vinegar is measured in “grains.” One grain is equal to one-tenth of one percent of acetic acid. The vinegar found at the grocery store is a 50-grain vinegar. A 100-grain vinegar is 10% acetic acid, and a 200-grain vinegar is 20% acetic acid.

  • Active ingredient: acetic acid
  • Amount to use: 0.5-2.0% of a 50-grain vinegar, which is equal to 0.25-1.0% of a 100-grain vinegar.
  • Associated problems:3 too much could cause a vinegar odor, possibly a need to slightly increase yeast levels (vinegar may affect yeast activity) and may increase proof time.

Prune Juice Concentrate

  • Active ingredient: predominately malic acid but also Benzoic and Salicylic acid, which occur naturally in prunes.
  • Amount to use: Add at 9-12%
  • Associated problems: may cause a darker and shiner crumb
  • Additional benefits:4 mainly used in whole grain breads to “round out” the grainy flavor and soften crumb (may need to eliminate emulsifiers). It is also an aid in anti-staling, may reduce the amount of sugar in recipes, reduce mix time by 5 minutes, slightly increase bread loaf volume, nutritional profile improvement of product and natural color enhancer.

Raisin paste concentrate: made from extruded raisins through a mesh screen

  • Active ingredient: predominately the naturally occurring propionic acid for the mold inhibition but also tartaric acid.5
  • Amount to use: 5-10%
  • Additional benefits: fat replacer, as raisin paste can be used to replace 50% of the fat in some cookie recipes. Also, a humectant, natural sweetener, flavor enhancer and nutritional profile improvement of product.

Raisin juice concentrate: made in a multi-stage process where pure raisin juice is extracted with water and then concentrated under vacuum to 70 Brix (70% soluble solids). It is very similar to molasses; however, it is less viscous.

  • Active ingredient: predominately propionic acid for the mold inhibition but also tartaric acid.
  • Amount to use: most effective usage level is 5-10%
  • Additional benefits: may reduce the amount of sugar in receipts, is a natural coloring agent and flavor enhancer to “round out” a grainy taste in whole grain breads, softens crumb, maintains breakage in crisp cookies, maintains moisture in soft cookies, improves nutritional profile of product, and maintains softness in cakes. May need to reduce or eliminate use of oxidizers in bread formulations and increase mix time slightly.
  • Associated problems:6 may cause a darker and shinier crumb and may impact the aroma of raisins at high usage levels. In yeast-raised goods, it may be necessary to increase the amount of yeast; as raisin juice can inhibit yeast activity.

Category 2: Cellular membrane disruption and cellular processes


  • Active ingredients: cinnamaldehyde, eugenol, related acids and alcohols
  • Amount to use: 1-2% dry spice8


  • Active ingredients: Eugenol
  • Amount to use: about 1% dry spice8

Cultured Wheat

  • Active ingredients: propionic, acetic and 3- phenyllactic acids and  bacteriocins
  • Amount to use:  0.5-1% cultured wheat powder

Cultured Whey products

  • Active ingredient: acetic, propionic and lactic acids7
  • Amount to use: 1-2% cultured whey products


In the pH range typically found in breads and bakery products, lowering crumb pH in and of itself  may not reduce mold incidence. The current strategy in most commercial bread baking facilities is to use a cultured wheat  containing naturally occurring propionates in conjunction with lowering crumb pH to around 5.10 to bring those propionates into a reasonable activity rate range.


Product claimed organic needs to be certified by USDA NOP.9 NOP is a regulatory program housed within the USDA Agricultural Marketing Service. It is responsible for developing national standards for organically-produced agricultural products. The product claimed organic must comply with the USDA organic regulations which is listed in the Code of Federal Regulations (Title 7 Part 205).1


  1. “7 CFR Part 205.” ECFR — Code of Federal Regulations. N.p., 11 Oct. 2016.
  2. Renee Alberts-Nelson. “Clean Label Mold Inhibitors for Baking”. Oklahoma State University Cooperative Extension FAPC-173, 2010.
  3. Williams, Tony, and Gordon Pullen. “Functional Ingredients.” Technology of Breadmaking (2007): 51-91.
  4. Sanders, S. “Using Prune Juice Concentrate in Whole Wheat Bread and Other Bakery Products”. Cereal Foods World. Vol. 36 (pp. 280-283), 1991.
  5. Cantor, Stuart. “Juicing-Up Products with Fruit-Based Ingredients.” Natural Products Insider. N.p., Dec. 1996.
  6. Fagrell, E. “Raisin Usage in Baked Goods.” AIB Technical Bulletin. Volume XIV, Issue 4 (pp. 5-6), 1992.
  7. Pyler, E. J. and Gorton, L. A. Baking Science & Technology. 4th ed. Kansas City, MO: Sosland Publishing Company. (pp. 456-459), 2008.
  8. Bullerman, L. “Mold Growth in Bakery Products and Its Prevention.” AIB Technical Bulletin. Volume XXII, Issue 6. 2000.
  9. “FAQ: Becoming a Certified Operation.” Agricultural Marketing Service. N.p., n.d.