Bringing speed, flexibility and quality to your frozen food processes
Liquid nitrogen (LIN) has been used by the food and drink industry for many decades, recognised for its superior ability to control temperature. Due to its own extremely cold temperature, liquid nitrogen can enable a cryogenic system to freeze or chill food within minutes. The fast freezing creates the formation of smaller ice crystals, which then leads to an improved product quality and reduced drip loss. Furthermore, liquid nitrogen can be used to remove heat from other processes to help prevent microbial growth, reduce cycle times, and/or increase production throughput.
From a commercial point of view, the speed of cryogenic freezing enables producers to process more product, more quickly. Cryogenic freezers can also be turned on and off easily and at short notice, meaning that production lines can easily be scaled up or down to meet demand. Both the equipment and the nitrogen can be configured in a mode that matches the scale of the food processing operation.
Continuous cryogenic freezers can be used in conjunction with high speed cutting, MAP and packaging machines to form one continuous production line. This can reduce labour requirements as there is no need to physically move product from batch freezers across to the cutting line, making the whole process seamless and more efficient. With a relatively small footprint, and rental models available, cryogenic freezing tunnels can deliver a flexible means of processing with high quality results.
What are the benefits?
Due to its extremely cold temperature, liquid nitrogen freezes food within minutes, significantly faster than traditional freezing technologies.
Superior looks and texture
There is less breakdown of cell structures when defrosted, so soft fruits and other fragile food products retain their good looks and texture
Less food waste
Cryogenic processes enhance the texture of foods and can result in less wasted product through sticking and degradation. Crust freezing can also allow for thinner, cleaner slicing and less waste.
Less moisture loss
Reducing the temperature quickly can lock in moisture.
Faster production times
Reach optimum temperature reduction in minutes. Easy to clean.
Smaller footprint in comparison to mechanical freezing
In addition to the cryogenic equipment itself, processing speeds also mean your product is ready for distribution faster, resulting in less space needed
Cost effective
Competitive pricing, rental possibilities and excellent gas efficiency
Flexible
Both the equipment and the nitrogen can be configured in a mode that matches the scale of the food processing operation. Quick to install and configure too.
How does it work?
Most mechanical freezers operate around -40⁰c leading to a much slower freeze. LIN freezes the moisture in the product far quicker than any mechanical freezing process. This leads to much smaller ice crystals, causing less damage to cell membranes. LIN can be utilised in freezer tunnels, batch freezers and through injection systems, where the liquid is mixed into the product itself while being mixed or formed.
Cryogenic batch freezers
Our Freshline® Batch Freezer has been specifically designed to meet the stringent needs of cookchill and cook-freeze in the catering industry. It is also ideal for food processors with batch or low volume freezing/chilling requirements. Typically the Freshline® Batch takes 20 minutes to refrigerate 100 kg of product. Both in-out and straight through versions are available.
Continuous tunnel freezing
Cryogenic equipment can run at temperatures much colder than other freezers, therefore maximum throughput for available floor space can be achieved. Tunnels can be configured in different sizes to make to most of processing space and desired throughput.
Liquid nitrogen injection (LIN-IS)
In mixing applications, LIN can also be mixed directly into hot products with a high water content to aid mixing, forming and shaping, such as burgers and plant-based food products. The Freshline® LIN-IS can be fitted on any type of mixer.
Grinding
During grinding liquid nitrogen can be used to eliminate frictional heat to help improve the throughput of mills, while also preventing the loss of flavour and aroma components in food additives, ingredients, and functional foods.
What processes are best suited to cryogenic freezing or chilling?
The frozen food market is rapidly expanding with the growing consumer confidence in the freshness and quality of frozen produce. Desserts, fruits and vegetables, seafood, meats and plant-based products are particularly well suited to cryogenic freezing and chilling, and a number of processes are used to capitalise on the trend. Producers use liquid nitrogen for ingredient chilling, grinding and campylobacter intervention too.
Product conditioning
Crust freezing
By freezing just the outer three or four millimetres of a product enables food manufacturers to cut thinner slices, using a faster blade speed, resulting in consistent, perfectly formed slices. Critically, crust freezing also prevents tearing – a major cause of food waste in the cut meat production process. Crust freezing can also help to maintain shape, harden the surface for more delicate processing or handling, and prevent moisture loss.
IQF
'Individually quick frozen' is a popular method of freezing sticky products such as prawns, diced meats, fruits or vegetables. In coating applications, the low temperature of liquid nitrogen allows it to enrobe individually quick-frozen (IQF) products in sauces while they freeze, helping produce an even coating.
Mixing and forming
Any food mixture which requires an optimum precise and repeatable temperature before the forming process in order to obtain a perfectly formed end product is a good candidate for LIN IS. Liquid nitrogen systems can bring about a rapid drop in temperature and thus a very efficient and repeatable chilling solution. Our LIN IS systems can be designed to be either bottom or top injection.
Cryogenic v mechanical freezing
Want to know more?
To discuss how we can help optimise your food process please call 0800 389 0202, fill out the form, email apukinfo@airproducts.com or sign up to our newsletter for our latest updates here.
