Common Microorganisms in Baked Goods: How Natural Preservatives Work
Baked goods are loved by consumers for their soft texture and rich flavors. However, during production, storage, and transportation, they are prone to spoilage due to microbial growth. This not only affects taste and causes economic losses but may also lead to food safety issues. Understanding the most common microorganisms in baked goods and choosing scientific preservation methods is key to ensuring product quality.
The 3 Types of Microorganisms Baked Goods "Fear Most": Why Do They Grow Easily?
Raw materials for baked goods—such as flour, sugar, oil, dairy products, and eggs—are rich in carbohydrates, proteins, and moisture. Additionally, issues like "exposure during cooling" and "varied packaging tightness" during production create a "breeding ground" for microorganisms. Among them, the following 3 types are the main causes of baked good spoilage:
Mold: The Microorganism That Causes "Visible Spoilage"
Mold is the "number one enemy" of baked goods, especially in high-moisture, high-sugar, and high-oil products like cakes, bread, and egg yolk pastries. Common types include:
- Penicillium: Often forms blue-green spots on the surface of bread and pastries, accompanied by a moldy smell. In severe cases, it produces harmful mycotoxins.
- Aspergillus: Prefers baked goods with oil and nuts. Its colonies are usually yellow or brown, and it breaks down oil to produce a rancid taste.
- Rhizopus: Grows easily in high-humidity environments, forming white fluffy hyphae that turn black over time.
Temperature greatly affects mold growth: at 20-30°C, visible colonies can form on baked goods in just 2-3 days. Low temperatures slow growth but cannot stop it completely.
Yeast: The "Invisible Spoilage Microorganism" That Alters Flavor
Unlike mold, yeast does not form obvious mold spots. However, it breaks down sugars in baked goods to produce alcohol and carbon dioxide, causing products to "taste off" and "expand". It is common in:
- High-sugar baked goods: Such as donuts and caramel bread. When sugar concentration is high but fails to fully inhibit yeast activity, yeast ferments slowly, giving products a slight alcoholic taste.
- Baked goods with dairy products: Such as cheese bread and cream cakes. Lactose in dairy products provides nutrients for yeast, which may reduce the product’s "softness" and make its flavor "sour".
Yeast growth is often hard to detect. By the time consumers notice "something is wrong with the taste", the product is no longer edible, which harms brand reputation.
Bacteria: A "Potential Threat" During Low-Temperature Storage
Compared to mold and yeast, bacteria are less "noticeable" in baked goods. However, some low-temperature-tolerant bacteria still pose risks, such as:
Bacillus cereus: Common in whole-wheat bread and multigrain crackers. Its spores can withstand high baking temperatures and reactivate at room temperature after cooling, possibly causing stomach discomfort.
- Lactic acid bacteria: Grow easily in baked goods with dairy products or fermented ingredients. They break down lactose to produce lactic acid, making the product "sour-tasting" and "sticky".
The growth of these bacteria is mostly related to "contamination after cooling" and "fluctuations in storage temperature". The risk increases significantly, especially when room temperatures are high in summer.
The 3 Natural Preservatives: How to Use Them Alone to Target Microorganisms?
To solve baked good spoilage, traditional chemical preservatives like sodium benzoate are gradually being phased out due to "safety concerns". Instead, ε-polylysine, natamycin, and nisin have become mainstream choices in the baking industry, thanks to their "high safety" and "targeted antimicrobial effects".
ε-Polylysine: A "Versatile" Broad-Spectrum Preservative for Mold, Yeast, and Bacteria
ε-Polylysine is a natural peptide produced by microbial fermentation. It is highly water-soluble (solubility up to 500g/L) and inhibits microbial growth by damaging cell membranes—making it a "broad-spectrum preservation guard" for baked goods:
- Against mold: It effectively inhibits the spore germination of Penicillium and Aspergillus. Adding 0.03-0.05g/kg to cakes and bread can extend mold growth time from 2-3 days to 7-10 days.
- Against yeast: For yeast in high-sugar baked goods, ε-polylysine blocks sugar metabolism and prevents alcoholic tastes.
- Against bacteria: It inhibits Bacillus cereus and lactic acid bacteria. Adding it to whole-wheat bread reduces the risk of bacterial reactivation during low-temperature storage.
Another major advantage of ε-polylysine is "high safety": it breaks down quickly into amino acids in the human body, leaving no residues or side effects—fully aligning with the consumer trend of "natural and healthy" baked goods.
Natamycin: The "Specialized Killer" for Yeast and Mold
Natamycin is a natural antifungal agent. It has a strong inhibitory effect on mold and yeast but little effect on bacteria—making it a "mold-specific guard" for baked goods:
Targeted mold inhibition: The minimum inhibitory concentration for Penicillium and Rhizopus is only 0.5-5μg/mL. Spraying it on pastry surfaces or adding 0.02-0.04g/kg inside can completely prevent mold spots, making it ideal for "mold-prone" baked goods.
- No impact on flavor: Natamycin is stable and does not break down at high baking temperatures. It also does not react with ingredients like flour and oil, preserving the original flavor of baked goods.
- Wide application: It can be added directly to dough or sprayed on surfaces before packaging to form a "protective film", blocking mold contamination in two ways.
For bakeries where "mold spoilage is the main issue", natamycin is a cost-effective choice.
Nisin: The "Inhibitor" for Bacteria, Protecting Products After High Temperatures
Nisin is a peptide preservative produced by lactic acid bacteria fermentation. It mainly targets Gram-positive bacteria and has little effect on mold and yeast—making it key for "bacteria control" in baked goods:
Inhibiting heat-tolerant bacteria: It effectively kills Bacillus cereus spores remaining after baking. Adding 0.03-0.06g/kg to multigrain bread and steamed buns reduces the risk of "stomach discomfort" caused by bacteria.
- Heat resistance: It can withstand high-temperature sterilization at 121°C and remains effective during baking—suitable for baked goods that require reheating.
- Synergistic flavor enhancement: Nisin is produced by lactic acid bacteria. A small amount added does not affect the taste of baked goods; instead, it works with dairy ingredients to "enhance flavor richness".
For bakeries where "bacterial contamination is the main risk", nisin is an essential preservative.
Combined Use Is More Effective: 2 Matching Plans for Full-Scenario Preservation
In actual production, baked good spoilage is rarely caused by "a single type of microorganism". For example, bread may face both mold and bacterial contamination. Combining the three preservatives achieves an "1+1>2" antimicrobial effect while reducing the amount of a single preservative used—better meeting safety standards. If you need a combined use plan, Bainafo Company is ready to help!
3 Key Tips for Bakeries Using Natural Preservatives
1. Choose the "main preservative" based on product characteristics: If mold spoilage is the main issue, prioritize natamycin; if bacterial risk is the main concern, prioritize nisin; for all-around protection, ε-polylysine is the basic choice.
2. Control the amount added to meet safety standards: The amount of all three preservatives must comply with safety regulations—avoid over-adding.
3. Combine with processes to improve preservation effects: Preservatives are not "omnipotent". They need to be paired with "low-temperature cooling", "airtight packaging", and "clean production" to maximize shelf life.
Conclusion
Spoilage of baked goods is essentially a "struggle between microorganisms, products, and the environment". As representatives of natural preservatives, ε-polylysine, natamycin, and nisin not only solve the problem of mold, yeast, and bacterial growth but also meet consumers’ demand for "natural and healthy" products. Whether used alone or in combination, choosing the right plan and method ensures food safety, extends product shelf life, and provides strong support for bakeries to reduce losses and improve competitiveness. Bring us your questions—Bainafo Company is always ready!
