Ozone Gas in the Flour Industry: Organic-Compatible Disinfection for Lentil, Chickpea, and Buckwheat Flours
Introduction
Microbiological safety in the flour industry is becoming an increasingly critical issue not just for wheat flour, but for alternative grain and legume flours such as lentil, chickpea, and buckwheat. In organic-certified production in particular, chemical fumigants are off the table, leaving producers with a much narrower set of tools for microbial load control and insect/mould risk management.
Ozone gas offers a residue-free, effective solution at this exact point for both conventional and organic flour producers. This post explains how ozone is used in flour production, the specific challenges that arise in alternative flours like lentil, chickpea, and buckwheat, and the advantage ozone offers from an organic certification standpoint.
Why Do Alternative Flours Carry a Different Risk Profile?
Unlike wheat flour, legume- and pseudo-cereal-based flours carry their own distinct microbiological and storage risks:
Lentil flour: Due to its high protein content and moisture retention capacity, lentil flour is more prone to mould growth than wheat flour. Legume-based flours also carry a higher risk of insect contamination.
Chickpea flour: Despite its relatively low moisture content, its high protein content makes it prone to mould growth and insect contamination under unsuitable storage conditions compared to wheat flour; being legume-based, it also carries additional risk from grain weevils.
Buckwheat flour: Although technically a pseudo-cereal, its high moisture absorption capacity and relatively higher fat content make it a product requiring close attention to mould and yeast development during storage.
As these flours are increasingly in demand alongside the gluten-free and organic nutrition trends, producers are pushed to seek alternatives to chemical fumigation.
The Incompatibility of Conventional Fumigation with Organic Production
Phosphine gas and similar chemical fumigants widely used in the flour industry are directly incompatible with organic certification standards (EU Organic Farming Regulation, USDA Organic, Turkish Organic Farming Regulation). Using these chemicals causes the product to lose its organic status.
This pushes organic flour producers toward either purely passive methods (cooling, vacuum packaging) or an effective, organic-compatible active solution. Ozone stands out as the leading technology in the second category.
How Is Ozone Used in Flour Production?
Ozone application in the flour sector comes into play at three core points:
1. Raw material disinfection: Before processing, lentil, chickpea, or buckwheat grains are treated with ozonated air to inactivate surface microbial load and insect eggs.
2. Storage area disinfection: Continuous low-concentration ozone injection into silos and storage areas reduces the risk of recontamination during storage and interrupts the insect development cycle.
3. Finished product (flour) surface treatment: After milling and before packaging, low-dose ozone can be integrated into the flour flow to further reduce microbial load in the final product — a step particularly favoured in organic flours where shelf life is critical.
Ozone's Advantage for Organic Certification
Ozone reverts to oxygen on its own within minutes of use, leaving no chemical residue on the product, equipment, or packaging. As a result:
- It is recognised as a permitted processing method under EU Organic Farming Regulation
- It does not require residue analysis reports during organic certification audits
- For brands labelling gluten-free products, it provides an additional layer of safety without increasing cross-contamination risk
These qualities also make ozone valuable from a marketing perspective for lentil, chickpea, and buckwheat flour producers specifically targeting an "organic" or "natural" positioning.
Points to Consider in Application
Ozone dose and contact time must be adjusted according to the flour's fat content and protein structure. In high-fat flours such as buckwheat in particular, excessive ozone exposure can accelerate fat oxidation, leading to undesirable flavour changes. Pilot testing and sensory evaluation are therefore an essential step before commercial-scale application.
When applied correctly, ozone offers a balanced solution that increases microbial safety while preserving the flour's nutritional value and sensory qualities.
The OCS Ozone Approach
At OCS Ozone, we offer flour producers customised ozone solutions for both conventional and organic-certified production lines. Taking into account the distinct fat and protein structure of alternative flours such as lentil, chickpea, and buckwheat, we determine the correct dose and application point together through pilot testing and sensory evaluation.
If you would like information about an organic-compatible, residue-free disinfection solution for your flour facility, get in touch.