Biology’s relationship with water and oxygen starts at “it’s complicated” and drifts into “seeing other people.” All life needs water and oxygen to live, but water and oxygen destroy life. Preserving food from farm to table has long been about keeping these two elements at bay.
In the early days, dehydrating items and locking them away in airless vaults accomplished this. Refrigeration and freezing came along next to enhance preservation without removing flavor/texture. Those efforts had some mediocre results.
It’s been a long time since the 60s and 70s. The evolution of IQF technology has brought the concept of individual quick freezing into a streamlined state. The fresh vs. frozen foods perception battle has gotten more complicated.
This list provides details on how IQF is doing now and how these advancements are impacting food products.
The benefits of IQF speak for themselves. The downside is in upfront costs and recouping that value from consumers. Frozen foods continue to struggle in an uphill battle against the perceived superiority of fresh food.
With these advancements, costs go down, and production speeds go up. On the retail front, fights for floor space show a definitive benefit for frozen foods.
Small and private labels make up 21 percent of frozen food sales. Consumers show long-term loyalty to cottage brands of frozen items.
Advancements in IQF tech stretch across both mechanical and cryogenic methods.
The first, and arguably, the most efficient form of IQF dominated the industry in the past few years. Most of the innovations come from a drive to improve mechanical IQF output.
Improvements to the process include power and resource optimization. Efficiency boosts prove useful, but movement and better separation of products are paramount.
Separation of the products (the key to IQF) creates innovation and hurdles for engineers working on these new technologies.
Adjusting the speed of fans and limiting the space inside of a freezer leads to better airflow. In turn, airflow improvements result in less snow and dehydration.
Less snow doesn’t only affect the product. With less build-up, up time for a vessel before defrosting also improves.
Voltage inverters regulate power consumption better than uncontrolled units. Regulating the power of fans, the conveyor, and temperatures allow fine-tuned control. This creates overall savings in energy with no change to the quality of products.
The use of frequency converters across a freezer system shows a total energy savings of up to 30 percent in some units.
Movement of product is everything in IQF. Too little movement and products clump together, creating texture and portion issues when defrosting. Too much movement and delicate products shred and tear.
The movement also has to transfer product through the freezing chamber while changing facing.
The following movement improvements still find use. Each iteration improves on and takes advantage of the strengths of its predecessors.
The original still sees use with hearty products such as corn and carrots. Airflow above and an open mesh below cools product with minimal snow. Cleaning is easy as the tray is removable.
The low number of moving parts is also a big win, as the airflow does all the work of moving the product.
The introduction of belts made softer and leafier foods freezable. With belts lower, wind speed achieved the same cooling.
The downside? Belts take a lot of cleaning between each product run. The entire machine needs to be stopped and scrubbed.
Currently, bedplates provide the best IQF movement results. The plates run asymmetrically through the vessel. This agitates the product while allowing for lower airflow speeds.
Workers remove the bedplates for external cleaning, allowing a quick swap to new bedplates to resume production.
The ability to remove bedplates also allows customization in the machine. The optimization of plates in the form of hole sizes and airflow speed maximizes fluidization.
This first major improvement in IQF processes finds new uses with new tech. Originally, the cost of liquid nitrogen to bathe products was prohibitive. The return in product quality was difficult to justify.
New technology makes use of hybrid methods to conserve the amount of chemicals consumed. This means less freezing solution with each kilogram of product produced.
Rolling-wave technology uses liquid nitrogen or carbon dioxide as its main freezing medium. Rather than submerging the product in these chilling solutions in bulk, the rolling-wave works like a bedplate.
The product moves in and out of the solution while agitating motion keeps it separated. The result freezes delicate products thoroughly while limiting oxidation. This works well for delicate items such as seafood which is prone to tissue damage from other freezing methods.
Not all oxygen is harmful when freezing. Some products, such as fish and mushrooms, start to break down quickly when deprived of oxygen. Oxygen injection creates better cell health while not impeding the freezing process.
Rather than dunking the product into carbon dioxide, this process drops an intensely cold semi-solid mixture. This works more like mechanical IQF, relying on product flow and controlled drops.
The end result is much the same. Leafy products or any other larger flat surface area products do well with this method.
Anti Cycle Vibration Cold systems (ACVCS) recycle air inside of a vessel. Instead of chilling external air, the air recycles within to lower energy consumption.
A bonus of this technique comes from fans in new positions to facilitate the recycling process. As air crosses through the product at multiple angles, it gives a more even freeze. Computers monitor the airflow to keep delicate products from tearing or stripping during the process.
Improvements to IQF technology continue to produce higher volumes of product at lower costs. Barring some massive shift in the paradigm of technique, this will be a gradual process.
The benefits that already exist continue to grow. Get involved with a stable and improving food preservation system like our Cold Chain Program.