The cold chain

Cold chain management is essential for preserving the harvested quality of fresh produce. Effective cold chain management begins on the farm and ends in the refrigerator at home.

The International Institute of Refrigeration (IIR) estimated that about one quarter of food production is lost due to a lack of or an incomplete cold chain in developing countries on average. In developed countries this number is about 9%. International Institut of Refrigeration :  Food Waste Reduction & Cold Chain Technologies, October 2015.

Temperature management is one of the most important factors affecting the quality of fresh produce. There is an optimum storage temperature for all products. This implies a number of steps where refrigeration is essential, by which the harvested or picked material will be: Harvested while it’s cool or Cooled in the field.

Transported to the pack house where they are regularly cooled: The longer a fresh vegetable is exposed to heat after it is cut, the more bacteria and excess moisture take their toll on quality. Quickly cooling stops bacteria growth and ensures freshness. Most storage rooms do not have the refrigeration capacity needed for rapid cooling. Therefore precooling must be a separate operation using special equipment.

Fresh foods continue to metabolize and consume their nutrients throughout their shelf life, from harvest or slaughter through packing, distribution, marketing and sale. Carbohydrates, proteins and other nutrients are broken down into simpler compounds often resulting in reduced quality or quantity of the foods, through respiration, enzymatic breakdown and microbial degradation. All of these processes are highly dependent upon temperature2.

The cold chain includes fresh tropical produce (at 12 to 18°C), chilled fresh produce and food products (at 0 to 4°C), or frozen food products (at -18°C). Reliable temperature control is required during storage and distribution.

An integrated cold chain includes:

  • 1. packing and cooling fresh food products,
  • 2. food processing including freezing of certain processed foods
  • 3. cold storage in short or long term warehousing of chilled or frozen foods
  • 4. distribution, cold transport and temporary warehousing under temperature controlled conditions
  • 5. retail refrigerated or freezer storage and displays at wholesale, retail and foodservice operations.

The cold chain sectors are shown below:

cold-chain

From the 2015 November food cold chain conference in Montreal, presentation by Roberto A. Peixoto Maua Institute of Technology- IMT, UNEP RTOC.

Refrigerated transport is a critical component of the cold chain and is explained in the infographic.

delivering-food

The importance of the cold chain in reducing greenhouse gas emissions

A 2015 study by the Global Food Cold Chain Council (GFCCC) highlights the importance of refrigeration technology in reducing greenhouse gas emissions associated with food waste (rotting food releases greenhouse gases such as CO2 and methane). According to a study by Bio Intelligence Service, a member of the Deloitte network, expansion of the food cold chain in developing countries could reduce net food waste greenhouse gas emissions by 180-550 million tons of CO2 equivalent annually between now and 2050, representing more than a 50% reduction in the carbon footprint of food waste currently due to the lack and/or inefficiencies of cold chains. GFCCC Executive Director Kevin Fay said, “It is important that we remain focused on all aspects of potential for greenhouse gas emissions reduction, especially those associated with food waste. Technology offers substantial savings today and in the future as new innovations evolve.”

 

There is an increasing recognition of the need to understand the total impact of the cold chain in terms of GHG emissions, food waste, and food waste greenhouse gas emissions and how these factors interlink. A recent review paper3 examines the cold chain as a transformative technology, identifying key intrinsic, indirect, and external factors that will favorably, unfavorably, or ambiguously impact the environmental profile of the food system. The review identifies key interactions and feedbacks between the cold chain, food production and consumption decisions, infrastructure development, and the global environment which are largely unexamined and in need of empirical data. Viewing cold chain expansion from this broader perspective is essential to understanding the changing impacts of the food system in developing countries and may inform future sustainability planning. The cold chain’s development is unlikely to wane, and as such, there is a need for studies which understand the relationships and effects of expanded refrigeration within the global food system. Refrigeration must be viewed from a larger perspective which includes analysis of social and behavioral shifts, creating a more complete assessment of the system’s sustainability impacts.

The figure shows the key factors related to the cold chain and their primary categorizations. Intrinsic factors relate to the technology itself; indirect factors are those relating to the technology’s adoption and interaction with other systems, and external factors occur independently of the technology’s presence.

The review paper concludes that analyzing the feedback loop between refrigeration, global temperature, energy consumption, and GHG emissions will be a critical task in anticipating the environmental impacts of the cold chain. Only by understanding the relationship between these factors, and promoting interventions such as efficiency improvements or changes to lower-emitting energy sources, can the cold chain be expected to expand in a way which aligns with sustainability objectives.

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thecold-chain

1 Food Waste Reduction & Cold Chain Technologies, October 2015.

2 Use of cold chains for reducing food losses in developing countries, PEF White Paper No. 13-03 Lisa Kitinoja The Postharvest Education Foundation (PEF) December 2013.

3Critical Research Needed to Examine the Environmental Impacts of Expanded Refrigeration on the Food System, Brent R. Heard and Shelie A. Miller, Environ. Sci. Technol. Advance Publication: Date (Web): Oct 14, 2016 DOI: 10.1021/acs.est.6b02740