With food waste at the top of all food producers' agendas, finding ways to reduce it across the whole production cycle has never been more important. Here, Neil Hansford, Industrial Cryogenic and Food Expert at Air Products, explains how crust freezing can make the cutting and slicing process more efficient and how simply it can be integrated into an existing production line.
Although slicing is one of the final stages in the food production process, it can result in substantial waste. If cutting is not done cleanly, food can tear, reducing the product quality and in some cases making it unsaleable.

However, crust freezing offers a solution that ensures product consistency and reduces waste by enabling accurate, clean cutting. The process of crust freezing uses the extremely low temperature of liquid nitrogen (LIN), which reaches -196°, to very quickly freeze just the outer three or four millimetres of a product. 

This enables food manufacturers to cut thinner slices of meat more accurately, 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. 
The extreme cold from 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 in the meat, and reduces moisture loss, maintaining the texture and quality of the meat slices.
The freezer technology associated with the use of LIN can be added to existing production lines without the need for major changes. Continuous cryogenic freezers can be used in conjunction with high speed cutting, MAP and packaging machines to form one continuous production line making the whole process seamless and more efficient. Smaller processors, who may not have the throughput or floor space to warrant investing in a continuous, in-line tunnel can also benefit from crust freezing by using a cryogenic batch freezer.

From a commercial point of view, the speed of cryogenic crust freezing makes it more energy efficient than traditional mechanical freezing, and enables producers to slice 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. This is critical for producers who need to be 'retail ready' and able to react quickly to new or increased orders.

Crucially for manufacturers of 'fresh' product, like raw meats, because such a thin outer layer of the product is frozen, it doesn't affect a product's 'chilled' or 'fresh' labelling. When it comes to more delicate bakery or confectionary products, such as cakes, gateaux or cheesecake, crust freezing prevents slices becoming deformed and ensures portions are evenly sized.

As well as cutting, crust freezing can be used to facilitate accurate product scoring. For example, a manufacturer of cookie dough crust freezes slabs of the dough before scoring individual portions so that sections can be snapped off easily and cleanly when needed.

With all food manufacturers driving towards optimised yields and reduced waste, crust freezing can deliver significant efficiencies that will help meet these goals.