Freezing food has been one of humanity’s staple food preservation methods for many thousands of years. This time-proven technique has continued to innovate and accelerate its development after the coming of the industrial age, but only in 1920 flash freezing was first discovered. A fisherman once realized that the fish he caught and then stored on the ice was just as appetizing as if it would have been cooked immediately. Armed with this newfound knowledge, Clarence Birdseye has gone on to invent the world’s first quick-freezing machine, which combined pressurized brine and water to freeze vegetables in record time.
Since its invention, flash freezing has become a staple of modern freezing technology. Continuing to develop this approach, more technology geared towards freezing food at more economic, efficient, and effective rates has been developed. In this article, we’ll look at some of them, and break it all down to see how it works.
Frozen food processing equipment can be distinguished into various subtypes, depending on the cooling method:
- Cryogenic – by using liquid nitrogen or carbon dioxide, which has already cooled, it’s possible to achieve a high grade of heat transfer and cool down food in a matter of seconds.
- Contact – by bringing the food in direct contact with cold surfaces, or placing it within a very cold liquid, this approach ensures the food is cooled quickly and significantly.
- Air-blast – one of the most common freezing approaches, it uses cool air to chill the food to a remarkably high degree, by moving frigid wind throughout the freezer.
Each cooling method comes with its advantages and disadvantages, from cooling substance scarcity to ease of operation. Some machines even combine different approaches to maximize yield or speed, depending on the specific needs of the processing company.
Another way of looking at the machinery that produces frozen food is to assess the final product. Here we can distinguish to possibilities:
- Packaged products – these products are typically frozen after storage, most often in conjunction with the contact freezing method. The advantage of these products is that it’s possible to freeze a large quantity with relatively minimal investment, however, the disadvantage is that freezing and unfreezing take significant amounts of time and the product itself is often damaged in the process.
- IQF freezing technology – IQF stands for individually quick-frozen, which is a type of freezing that is done while separating the individual pieces of the frozen goods. This is most often seen in air-blast or cryogenic freezing approaches, as processing tends to be much faster and allows for the attention to detail this type of freezing would require. Most often you will notice that berries, several types of fruit, vegetables, seafood, certain dairy products, and even poultry will be processed that way. The reason for this is that it allows the buyer to have an easier time picking out just as much as they need, and it creates a premium product that’s available for affordable prices.
In the modern freezing industry, IQF freezers hold special importance as they provide the tools for efficient freezing of individual products at high rates. Depending on the type of set-up, it’s even possible to freeze diverse types of products inside the same freezer all year around, for instance. Given this, it’s important to investigate what kinds of freezing techniques are used to make it as productive as possible.
- Impingement freezers – these are a type of freezers that feature a high volume of pressurized freezing air, spread across the frozen product at remarkably high velocities to induce a quick and effective freeze. By maximizing speed it’s easier to ensure that the frozen product preserves most of its natural properties, including taste, smell, texture, and more.
- High yield – one of the main priorities of IQF freezing is speed, as it helps the product keep its natural appeal and minimise product dehydration. Given high processing speeds and low dehydration, it’s only natural that the yield would be high too. Coupled with bedplates that are well equipped to house exceedingly high volumes, the modern IQF freezer can process up to 15 000 kg/h.
- Energy efficiency – progress in the freezing industry has created the perfect opportunity to minimize costs by innovating sustainable solutions. As a result, recirculated air flow becomes a valuable resource to cut down on expenses. Additionally, being able to adjust fan speeds lets the frozen food production company adapt to several types of products on the fly. It also means that significant savings can be made when the volume necessary to freeze is low.
- Food safety – finally, food-safe technology has become a necessity, as availability has taken the backstage. People nowadays are much more aware of what they are consuming and food standards have tightened the regulations to allow only high-quality products to go through. That’s why food processing companies need to step up and offer a design that’s ahead of the curve and can offer long-term food-safety.
Depending on the type of frozen food, special considerations need to be taken to ensure the packaging will provide the necessary support towards freezing, storage, transportation, and in some cases, even cooking.
Common packaging materials are derived from polyethylene film that can withstand extremely low temperatures without becoming damaged. Less modern approaches involve using cardboard boxes, laminated paper, and aluminum foil.
The freezing world is ripe for innovation and change, as progress continuously has been made to make the lives of consumers better. Frozen foods have become a growing reality for many consumers, offering a more affordable, less time-intensive alternative for cooking and eating healthy. The blend of convenience, easy storage, and good nutritional value depending on the freezing process, creates a product that’s hard to resist. Additionally, frozen food production serves to directly combat worldwide food waste, as products can be stored for as long as needed and used in the necessary context. From your favorite restaurant to a quick and easy meal on a Wednesday night, we’ve all benefited and will continue to benefit from them in the future.