The same energy that warms your skin in the sun is now transforming how our food is prepared, making it safer, tastier, and more nutritious while saving energy.
When you bite into a perfectly roasted nut or enjoy a brightly colored dried fruit, you're probably not thinking about the heating technology that made it possible. Yet, behind the scenes, a quiet revolution is underway in food processing, powered by a technology we experience every day—infrared radiation. The same fundamental energy that warms your skin in the sunlight is now being harnessed to make food processing faster, more energy-efficient, and better at preserving the foods we love.
Infrared heating might sound like science fiction, but it's one of the oldest forms of heat transfer in the universe. What's new is our ability to precisely control it for everything from killing harmful bacteria to peeling fruits with minimal waste1 8 . This technology offers a compelling alternative to conventional heating methods, with remarkable benefits for our food, our planet, and our palates.
Infrared radiation occupies a sweet spot in the electromagnetic spectrum—between visible light and microwaves—with wavelengths ranging from 0.75 to 1000 micrometers2 7 . While invisible to our eyes, we perceive it as heat, much like the warmth we feel from sunlight or a fire.
What makes infrared heating unique is how it transfers energy. Unlike conventional heating that slowly warms food from the outside in through hot air or surfaces (convection and conduction), infrared energy travels directly into the food, causing water molecules within to vibrate rapidly at frequencies of 60,000-150,000 MHz, generating heat from the inside out2 6 .
Wavelengths of 0.75-1.4 μm, effective for rapid surface heating
Wavelengths of 1.4-3 μm, balanced surface and penetration
| Product | Spectral Peak (μm) | Depth of Penetration (mm) |
|---|---|---|
| Wheat Bread | 1.00 | 11-12 |
| Potato | 1.00 | 6 |
| Raw Apple | 1.16 | 4.1 |
| Raw Apple | 2.36 | 7.4 |
| Wheat Grain | 1.00 | 2 |
| Carrot | 1.00 | 1.5 |
| Tomato Paste | 1.00 | 1 |
Source: Adapted from Ginzberg, 19696
The applications of infrared technology in food processing are surprisingly diverse, offering advantages at nearly every stage of production.
Infrared heating provides an effective non-chemical method for reducing pathogens on food surfaces1 . Its limited penetration depth, often considered a drawback for some applications, makes it perfect for surface decontamination without unnecessarily heating the entire product8 . This has proven effective for everything from decontaminating spices to surface pasteurization of eggs and fruits8 .
Infrared peeling represents a significant advancement for fruits and vegetables like tomatoes, peaches, and ginger. Traditional methods using steam or lye often damage the edible portion and create significant waste. Infrared peeling efficiently removes skins with minimal damage to the edible portion, making it an eco-friendly option that preserves more of the valuable food material1 8 .
Infrared drying operations have shown remarkable efficiency in preserving the quality of fruits, vegetables, and grains. Compared to conventional hot-air drying, infrared can better retain heat-sensitive nutrients and compounds while reducing processing time1 2 . Similarly, infrared roasting contributes to the development of desirable color, flavor, and texture attributes in nuts and coffee beans while using less energy1 .
Anyone who has thawed frozen food knows the problem of uneven results—partially cooked edges while the center remains frozen. Infrared thawing provides faster and more uniform heating, reducing the problematic "drip loss" that diminishes quality and results in better-preserved textures1 .
To understand how scientists are validating infrared technology, let's examine a crucial experiment detailed in a 2025 study that combined computational modeling with real-world testing to design an industrial-scale surface decontamination process8 .
Researchers began with experimental studies using both a black aluminum cylinder and fig samples to measure temperature changes during infrared heating. They carefully monitored the effects of different infrared source configurations and surrounding air temperatures.
Next, they developed a sophisticated computational mathematical model to simulate the complex heat transfer occurring during infrared processes. This model accounted for multiple infrared sources and reflectors within a heating cavity—a significant advancement over earlier, simpler models.
The model was then validated against experimental data to ensure its accuracy before being applied to simulate surface decontamination processes and design an industrial-scale system8 .
The research team found strong agreement between their computational model and experimental results, confirming the model's reliability for predicting temperature changes during infrared processing.
When applied to surface decontamination of figs, the validated model demonstrated that infrared heating could effectively reduce microbial contamination while preserving fruit quality. The model also revealed how strategic placement of multiple infrared sources and reflectors could optimize heating uniformity—a crucial factor for industrial applications where consistent results are essential8 .
| Food Product | Infrared Type | Reduction in Microbial Load | Quality Preservation |
|---|---|---|---|
| Figs | Far-IR with UV | Significant reduction | High - maintained texture & color |
| Shell Eggs | Far-IR | Effective surface pasteurization | Excellent - no damage to internal quality |
| Frankfurters | Far-IR | Pathogen reduction achieved | Good - maintained sensory properties |
| Strawberries | Far-IR | Effective surface decontamination | High - preserved appearance & firmness |
| Almonds | Mid-IR | Significant microbial reduction | Excellent - maintained crunch & flavor |
Source: Adapted from various studies8
The advantages of infrared heating over conventional methods are substantial and multifaceted:
Infrared systems convert most electrical energy directly into radiant energy, with electrical emitters achieving 78-85% conversion efficiency—significantly higher than many conventional systems6 .
Infrared systems produce no volatile organic compounds, carbon monoxide, or nitrogen oxides during operation, and don't contribute to air pollution like fossil fuel-based systems2 .
Infrared equipment tends to be more compact than conventional systems, saving valuable floor space in processing facilities2 .
| Equipment Type | Key Features | Common Food Applications |
|---|---|---|
| Short-wave/Electric Emitters | Very high emissive power; temperatures >400°C; 78-85% efficiency | Rapid surface heating, baking, thin-layer drying |
| Medium-wave IR Emitters | Wavelength 1.4-3.0 μm; moderate penetration | Drying, curing, roasting of nuts and grains |
| Long-wave/Far-IR Emitters | Wavelength 3.0-1000 μm; well-absorbed by foods | Low-temperature processes, combination heating |
| Catalytic Flameless Gas Emitters | No visible flame; wide wavelength range; 30-75% efficiency | Surface pasteurization, gentle drying applications |
| Reflector Systems | Direct and focus IR energy; improve efficiency | All applications - crucial for uniform heating |
Despite its considerable advantages, infrared heating does face some challenges. The limited penetration depth can restrict its effectiveness for thick foods, and the high surface temperatures require careful control to prevent burning4 7 . Additionally, different food components absorb infrared energy differently, requiring process optimization for each application.
The future of infrared heating likely lies in combination approaches. Researchers are finding that pairing infrared with other technologies like microwaves, ultraviolet, or conventional heating creates synergistic effects that overcome the limitations of individual methods while enhancing their advantages1 2 .
"Further research on optimization, process modelling, and the integration of IR heating with other technologies could expand its applicability and effectiveness, paving the way for more sustainable and high-quality food processing solutions"1 .
Infrared heating represents more than just another technological innovation—it's a fundamental shift toward more intelligent, efficient, and sustainable food processing. By harnessing the natural principle of radiant energy transfer, this technology offers solutions to some of the most persistent challenges in food preservation and safety.
As research continues to optimize and expand its applications, we're likely to see infrared technology play an increasingly important role in creating the safe, nutritious, and high-quality foods we'll enjoy in the future. The invisible light that brings warmth to our world may well be the key to building a better food system for generations to come.