Have you ever faced this frustrating situation?
You've added oxygen absorbers to your packaging, yet the product still develops mold. Not only does this increase spoilage and waste, but it can also seriously damage brand credibility.
When oxygen absorbers "don't work," the issue is rarely the absorber alone. In most cases, the root cause lies somewhere in the overall packaging and production system. Below, we break down the problem from four critical angles to help you quickly identify risks and implement effective solutions.
1. Start with the Packaging System
If mold appears despite the use of oxygen absorbers, packaging is often the first place to investigate. Packaging is the product's primary barrier-once it fails, even the best absorber cannot compensate.
Seal integrity
Poor sealing is one of the most common causes. Issues such as pinholes in laminated films, wrinkled seals, or insufficient heat-sealing temperature or pressure allow oxygen to continuously enter the package. As a result, the oxygen absorber becomes overwhelmed or exhausted prematurely.
How to check:
- Submerge the sealed package in water and gently squeeze it. Visible bubbles indicate leakage points (effective for obvious leaks).
- For more precise evaluation, use a professional seal integrity tester to detect slow or micro leaks.
Barrier performance
Even without visible damage, packaging films with a high oxygen transmission rate (OTR) allow oxygen to slowly permeate over time, eventually disrupting the preservation balance.
For most food products, laminated films with an OTR of ≤ 20 cm³/(m²·24h·0.1 MPa) are recommended, though this should be adjusted based on product characteristics and shelf-life requirements.
2. Check Whether the Oxygen Absorber Is Used Correctly
Once packaging issues are ruled out, the next step is to evaluate oxygen absorber selection and handling-an area that is often underestimated.
Correct type and capacity
Oxygen absorbers are not universal. The required capacity must be calculated based on package volume:
Required absorber capacity ≥ package volume × 21%
(the oxygen concentration in air)
In addition, different food types require different absorber designs. For example, high-moisture products such as baked goods should use Yome oil- and moisture-resistant oxygen absorbers to prevent premature deactivation.
Proper handling and placement
- After opening, Yome oxygen absorbers should be used and sealed within one hour to avoid early oxygen consumption.
- When using multiple absorbers from the same pack, spread them evenly on the work surface. Stacking absorbers accelerates oxygen uptake and heat generation, reducing their effective lifespan.
- Yome oxygen absorbers are single-use only and must never be reused.
3. Understand the Product's Inherent Risk Factors
If the product itself is highly susceptible to spoilage, even optimized packaging may fall short. Three key parameters must be tightly controlled:
Water activity (Aw)
Most molds can grow at Aw > 0.80. Even in low-oxygen environments, certain oxygen-tolerant molds can still develop slowly. Water activity should be measured accurately using a water activity meter.
pH level
Products with neutral or slightly alkaline pH values are more prone to mold growth. Where appropriate and compliant, pH adjustment using approved acidulants can improve stability.
Initial microbial load
High mold counts in raw materials are often the true root cause. Raw materials should be tested before production, and any non-compliant batches must be rejected to reduce contamination at the source.
4. Review the Production and Processing Workflow
Even minor lapses during processing can undo all preservation efforts. Pay close attention to the following areas:
Sterilization
If processing temperature or time is insufficient, mold spores may survive. Oxygen absorbers cannot stop the growth of spores that were never properly inactivated.
Cooling and environmental hygiene
Sealing products while they are still hot can lead to condensation inside the package, increasing water activity. Poor hygiene in cooling or packaging areas may also cause secondary contamination. Packaging rooms should be regularly monitored to maintain proper cleanliness standards.
Time required for oxygen reduction
Oxygen absorbers typically need 24–48 hours to reduce oxygen levels below 0.1%. If contamination occurs during this window, later oxygen removal will not reverse mold growth. This makes strict hygiene control throughout the entire process essential.
Key Takeaways & Corrective Actions
To reduce mold risk effectively, follow this structured checklist:
- Verify packaging seal integrity and barrier performance; optimize sealing parameters or switch to compliant materials if needed.
- Confirm Yome oxygen absorber type, capacity, and shelf life; standardize storage and handling procedures.
- Measure water activity, pH, and raw-material microbial levels; adjust formulations or processes accordingly.
- Improve sterilization, cooling, and production-area hygiene controls.
If mold persists after these steps, oxygen-tolerant molds (such as Penicillium or Aspergillus) may be involved. In such cases, a combined strategy-approved preservatives, low-temperature storage, and controlled comparison testing-may be required to pinpoint and resolve the issue.
Have questions about your specific product?
Whether you package baked goods, nuts, freeze-dried foods, or meat products, feel free to reach out. Our team can help analyze your application and recommend targeted improvements to protect product quality and shelf life.
