The technicalities of freezing food

Tatjana Milenovic, food and beverage group vice president at ABB, explains the complications and advantages of freezing frozen food.

Helsinki, Finland: Food and beverage manufacturers understand that they must reduce food waste to improve profitability and their environmental impact.

Freezing is a simple way to preserve food for long periods of time, particularly as food can be frozen either directly at the source or once it has gone through processing. This flexibility to preserve perishable food at the source is crucial across the globe. For example, in developing countries it is estimated that up to 50 per cent of root crops, fruits and vegetables are wasted due to improper transport and storage.

However, this is not to say that producing frozen food is simple. There are many different and complex processes that must work together to deliver frozen food to the consumer market. For example, freezing, storing and maintaining temperature during transportation all require specialist technology to properly maintain the product and ensure that it is kept safe for consumption.

Freezing methods
Freezing is a well-established food preservation method. However, it is a delicate task. If large ice crystal form within the products cells it can easily destroy the cellular membrane of the product, which can not only alter the thawed products taste but can potentially make it unsafe for consumption.

There are three main freezing methods; air blast, contact and immersion freezing. Each of these methods has a number of additional variants to cater for specific food types or cellular structures, which can affect the ability to freeze and subsequently thaw food correctly.

Air blast freezing works by passing products through below-freezing air flows. Since air blast can freeze products on the move, this method benefits rolling production. Contact freezing is when products are placed between two metal plates with internal cooling systems. This method is three times faster than air blast but is only suitable for products with two flat surfaces, such as prepackaged items.

Immersion freezing requires products to be immersed or sprayed with liquid refrigerant. There are a variety of different refrigerant liquids available, however, the most common are liquid nitrogen or a mixture of ethanol and dry ice.

Regardless of the method, freezer components must be tough to cope with the drastic temperature shifts between their insides and outsides. Furthermore, to keep up with hygiene requirements in the food industry, freezers must be regularly and thoroughly cleaned. This can mean that certain parts, such as paint, can corrode which could contaminate the food products.

For this reason, at ABB we provide motors that have been designed from the ground up to only include unpainted components. These motors are made for use in freezer applications where the rapid changes in temperature — from 25 degrees to minus 30 degrees Celsius — and humidity from 0–50 per cent, can lead to flaking and chipping on painted motors.

Cold supply chains
Cold supply chains are the leading modern method for transporting items that must be kept at a constant cold temperature. In a cold supply chain, every part of storage and transportation is temperature controlled to stop products from decaying. Food products can be very sensitive to temperature fluctuations, with sudden changes often leading to premature spoilage.

In fact, research demonstrates that there are several key variable factors in the food spoilage process: pH, water activity, salt content, gas composition, pressure, humidity and temperature. Of these, temperature is the main instigator, as when a product is stored above its individual temperature limit it can encounter rapid bacteria growth, which accelerates decay.

Modern food supply chains are also long, meaning that keeping produce at a constant temperature is vital. However, due to the rigorous standards that implementing a cold supply chain requires, not everyone is able to use them. This is because the window of temperatures at which products must be kept is very narrow, so any deviation and the produce will be deemed unsafe and rejected. As such, the cold system must be able to be monitored and controlled from start to finish.

Therefore, paper controls and monitoring cannot keep up with the precision needed for cold food supply chains, because they can only register an average temperature. Accurately controlling the temperature inside cold storage requires a smart system, because multiple sensors can record and analyze a constant temperature.

For example, imagine a refrigerated container being kept at minus eight degrees Celsius to store frozen fruit. If one of the cooling systems was to malfunction, a paper-based system would only register a slight anomaly in temperature variation. A smart sensor-based system would be able to identify exactly which cooling system was malfunctioning and directly identify the affected packages as well as alert maintenance and monitoring teams.

ABB’s ControlMaster range offers a choice of communications options. Ethernet communications provide the ability for users to be automatically notified of critical process events via email. The systems also allow for remote monitoring through the ControlMaster’s integrated webserver, or by simply using a standard web browser.

Overall, freezing is an extremely flexible method of preventing food waste. It can cater for all types of food and, though intricate, the tools for implementing cold supply chains are prevalent and widely accessible.

As food consumption and the global population continue to grow, food waste must be reduced. One easy method of achieving this is extending the life span of the products on the market. Freezing food is a well-developed technique that can reduce food waste in all parts of the food chain and hopefully, the one billion tons of food wasted every year will be reduced.

ABB makes electrification products, robotics and motion, industrial automation and power grids serving customers in utilities, industry and transport and infrastructure globally.

http://www.abb.com

WORLD NEWS

EU help needed to resolve Turkish border delays

Geneva, Switzerland: The IRU has called on the European Commission to intervene in the treatment of truck drivers at Turkish borders. Turkey is not allowing …

READ THE FULL STORY >

Netherlands to Russia/China pilot rail service for fresh salmon

Duisberg, Germany: DBO Bahnopertor has run the first container train load of fresh salmon from the Netherlands to Russia and China. It is the first …

READ THE FULL STORY >

GCCA partners with Distillery Association for hand gels

Washington, DC, USA: The Global Cold Chain Alliance and the Distilled Spirits Council of the United States have a website to help distillers making hand …

READ THE FULL STORY >

Lineage Logistics helps Los Angeles in food campaign

Los Angeles, USA: Lineage Logistics working with NBA superstar, Anthony Davis’ Family Foundation to the boost the Help Feed the Frontline Fighting Covid-19 – LA …

READ THE FULL STORY >

WHAT’S ON

  • Engage Conference
    Talent in Logistics Engage Conference takes place on 21 April at Cranfield, UK

Latest Tweets

Coronavirus: Another folly in the making: bit.ly/2R6rsNS pic.twitter.com/g1hX1q1fpK

© 2020 Global Cold Chain News | Terms of use | Privacy Policy
Commercial Transport Publishing Limited, registered in England and Wales, Company No: 6453302. Registered Office: 6 Corunna Court, Corunna Road, Warwick CV34 5HQ