Improving Your Bakery Products with Mold Inhibitors

Microbial spoilage of bakery products is a common concern among bakeries worldwide. Given finished products just out of the oven are microorganism-free, the post-bake environment, airborne pollutants, and surface contact from equipment, packaging, or food handlers can contaminate the final product. Thus, it is vital for bakeries to protect the post-bake environment and to guarantee the microbiological stability of baked goods.

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Overview of how to prevent mold issues:

1. A clean and sanitized environment
2. Reduced water activity
3. Better Packaging like modified atmosphere packaging
4. Anti-mold ingredient

How Mold Grows

Mold is the most common microbial spoilage found on baked goods. Molds are multicellular fungi that can spoil food and pose health risks. These fungi are more complex than single-celled organisms like yeast and bacteria. Mold typically appears as fuzzy spots in various colors, including green, black, or white, and can significantly affect the shelf life and safety of baked products.¹

They are characterized by: ¹

•     Molds are non-motile, filamentous, and branched microorganisms.
•     Their cell walls are composed of cellulose, chitin, or a combination of both.
•     They typically grow in the form of fine branching filaments called hyphae which can aggregate to form a mycelium.

Mold growth can also cause undesirable odors, and blemishes on the surface of baked goods affecting the overall acceptability of the product, and causing financial losses to bakers and consumers.¹﹐²﹐³

Factors affecting mold growth include:

1. Water activity (aw) and moisture content: mold growth occurs in high aw values >0.8, except in xerophilic molds that can grow at water activities down to 0.65. Usually, baked goods are intermediate to high moisture content food products, this can affect microbial growth due to the availability of water for microbial growth. Moisture condensation on product surface due to inefficient cooling before packaging can conduct mold growth.¹
2. pH: low pH conditions limit mold growth, these acidic conditions can also impact the performance of mold inhibitors. Molds are more tolerant to pH changes than bacteria, some mold strains can resist acidic conditions of pH  3.5-5.5, and thus mold growth represents a bigger concern than bacterial contamination in baked goods with lower pH values.¹
3. Temperature: mold growth occurs ideally in a temperature interval of 18-30°C (64-86°F). Reduction of temperature conditions from the ideal growth temperature has been shown in several research studies to significantly increase product shelf life. As previously mentioned, most microbial contamination is eliminated in the baking steps, and molds and yeast are usually inactivated when the interior temperature of the product reaches about 55-60°C (135-140°F).¹
4. Organic material: raw ingredients for baked goods are all sources of potential feed for mold growth. Fungal spores are particularly widespread in bakeries due to their presence in flour and potential spread throughout the production environment via air movement. A raw material quality assurance program, followed by good manufacturing practices can prevent the spread of fungal spores that may contaminate the final product.¹

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The most commonly found molds in the baking industry are:¹

•    Aspergillus niger: Black mold
•    Aspergillus glaucus: Green or grey-green mold
•    Aspergillus flavus: Olive green mold
•    Penicillium sp.: Blue-green mold
•    Rhizopus nigricans: Grey-black mold
•    Mucor sp.: Grey mold
•    Neurospora sitophila: Pink mold

How to Prevent Mold

Mold growth can be prevented by controlling the factors affecting its growth, as mentioned before water activity, temperature, pH, and organic material are the main driving factors of mold prevention. As well as by controlling the potential contamination of the post-bake environment.

1. Reformulation

Formulating products with lower water activity by the usage of polyols, glycerol, honey, sugars, fiber, hydrocolloids, and salts can aid in the growth of mold growth by decreasing the accessibility of water. Reduction of pH values can also aid in the prevention or control of microbial growth, this can be accomplished by increasing fermentation time, usage of acidulants, like fumaric acid or acetic acid, and/or lactic acid bacteria from sourdough. ²﹐³

Finally, freezing can also aid in controlling microbial growth by limiting the amount of water available for microbial growth. ²﹐³

2. Modified Atmosphere Packaging

It has been shown that a humid environment encourages mold growth.⁵ The usage of modified atmosphere packaging has been growing as a potential alternative to prevent and control mold growth in baked goods during storage. High levels of CO² in the packaging can inhibit fungal growth. Studies have shown that packaging with 100% CO² can prevent mold growth for extended periods, regardless of water activity levels in the product. Even at lower concentrations of around 60-80% of CO², it has shown promising results significantly increasing the product shelf life. This processing technique reduces the oxygen available for microbial growth, and limits water activity.  ²﹐³

3. Usage of Mold Inhibitors

1. Conventional mold inhibitors

• Sorbic acids and sorbates: they are recognized anti-mold agents, and are generally recognized as safe for usage in food products. The usage level of sorbate in baked goods ranges from 0.0001-0.3%, at this concentration sorbate does not significantly impact quality. However, higher levels have been shown to affect taste and flavor. Another drawback is the negative effect on yeast, affecting loaf volume and producing sticky dough that it’s difficult to process. ²﹐³
• Propionic acids and propionates: calcium propionate is used to prevent bacterial and mold growth in food products. Usage in formulation can range from 0.003-0.3%. In contrast with sorbates, they can be directly applied to the formulation without affecting yeast activity. ²﹐³

     2.    Natural alternatives:

• Vinegar:  is a natural mold inhibitor due to its acetic acid content, which lowers the pH of baked goods, creating an unfavorable environment for mold growth. It can be used at levels ranging from 0.5% to 2.5%, depending on the desired level of mold inhibition and the product’s pH. ⁴
• Cultured wheat: is a fermented wheat product that contains organic acids, primarily lactic and acetic acid, which inhibit mold growth by lowering the pH. It is typically used at levels of 1% to 5% in baked goods, depending on the desired level of mold inhibition and the product’s pH. ⁴
• Raising juices: produced by fermenting various fruit or vegetable juices, contain organic acids such as acetic and lactic acid that inhibit mold growth by lowering the pH. These juices can be used at levels ranging from 1% to 3% in baked goods, with specific usage levels varying based on the type of raising juice and its acid content. ⁴

Solutions Offered by AB Mauri

AB Mauri offers a certified organic clean-label preservation technology with its Organic BakeGard™ VP. This buffered organic vinegar product offers a functional replacement for cultured wheat, cultured starch, and calcium propionate that is more effective than traditional vinegar and free propionic acid for use in bread/rolls, tortillas, and other yeast-raised bakery applications.

Functional Properties

• Functional replacement for cultured mold inhibitors or calcium propionate
• Recommended for use in breads, rolls, tortillas, and other yeast-raised applications
• Safer to use and better performance than traditional vinegar
• Produces a clean flavor profile and does not influence the baked crumb color
• Does not utilize propionic acid as the functional anti-microbial organic acid
• Inhibits a broad spectrum of molds and rope in yeast-raised applications and some chemically leavened applications such as tortillas
• Verified 100% biobased through C14 testing
• Safe processing and handling
• A shelf life of twenty-four months can be obtained when stored unopened in a cool, dry area.  
• Certified Kosher

Recommended Usage Rates

For 100 pounds of flour or cereal:

•  Breads and rolls 0.75% – 2.50%
• Bagels and flatbreads 0.75% – 2.50%
• Flour tortillas 0.75% – 2.50%
• English muffins 1.00% – 2.50%
• Pizza 0.75% – 2.50%

Good Manufacturing Practices

Controlling the contamination of the production post-bake environment is one of the most effective ways to prevent and control mold growth. Minimizing the potential risk of contamination lowers the need for other prevention and control strategies by limiting the risk of the contamination itself. Following good manufacturing practices, having quality control systems for incoming ingredients, and developing the appropriate hygiene and sanitization procedures can significantly reduce the risk of microbial contamination.²﹐³

In conclusion, mold growth is one of the biggest challenges confronted by bakeries worldwide. Hundreds of tons are thrown away daily due to mold. It is important to provide safe and delicious products to consumers and steps to guarantee microbiological safety. Several techniques are available to prevent and control mold growth since there is no one solution for preventing mold growth. An integrated solution that takes into account all these potential affecting factors is needed.⁶

References

1. “Mold: Baking Processes.” BAKERpedia, 24 Feb. 2024, bakerpedia.com/processes/mold/. Accessed 21 July 2024.
2. Garcia, Marcelo Valle, Angélica Olivier Bernardi, and Marina Venturini Copetti. “The fungal problem in bread production: Insights of causes, consequences, and control methods.” Current Opinion in Food Science 29 (2019): 1-6.
3. Saranraj, P., and M. Geetha. “Microbial spoilage of bakery products and its control by preservatives.” International Journal of Pharmaceutical & biological archives 3.1 (2012): 38-48.
4. “Clean Label Mold Inhibitors: Baking Ingredients.” BAKERpedia, 22 Feb. 2024, bakerpedia.com/ingredients/clean-label-mold-inhibitors/#:~:text=What%20are%20Clean%20Label%20Mold,a%20wide%20range%20of%20benefits. Accessed 21 July 2024.
5. Alpers, Thekla, et al. “Impact of storing condition on staling and microbial spoilage behavior of bread and their contribution to prevent food waste.” Foods 10.1 (2021): 76.
6. Ben Rejeb, Ines, et al. “Bread surplus: a cumulative waste or a staple material for high-value products?.” Molecules 27.23 (2022): 8410.

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