Agri Health

Overview

The  food choice expectations of people living in developed countries are  made possible by affordable refrigeration systems across the entire food  supply chain. Introducing similar systems for developing countries will  be difficult and will require large amounts of energy. Avoiding  refrigeration dependence is difficult when economic development depends  on exporting food to more industrialized countries (FAO Policy Brief).  Refrigerated storage can account for up to 10 percent of the total  carbon footprint for some products when electricity inputs, the  manufacturing of cooling equipment, and GHG emissions from lost  refrigerants are taken into account (Cleland, 2010).
Active cooling  depends on electricity supply. Further solutions are passive  evaporative-cooling technologies and stand-alone solar chiller – once  they become economically viable. According to Bundschuh and Chen  improvements to technical elements and operation of modern refrigeration  systems have the potential to reduce energy consumption by 15-40%.
In the post-harvest cycle cooling is particularly crucial in the stages of pre-cooling and cold storage.

Pre-Cooling

According  to the FAO, pre-cooling is “amongst the most efficient quality  enhancements available” and is regarded “as one of the most value-adding  activities in the horticultural chain”.

 Pre-cooling refers to the rapid removal of field heat shortly after the  harvest of a crop. Field heat can be defined as the difference in  temperature between the temperature of the crop harvested and the  optimal storage temperature of that product. Benefits of pre-cooling  include:

· lowering the required workload of a cold storage since optimum storage temperature is reached more quickly

·  restricting and minimizing respiratory activity, thereby conserving the  weight of the produce, and enzymatic degradation of the produce  harvested; thus preventing softening, water loss and wilting

· preventing microbial growth, such as bacteria and fungi thereby decreasing the rate of decay

· decreasing rate of ethylene production and the impact on ethylene sensitive produce

· delaying chilling injuries for certain fruits

· increasing  the daily intake into storage facilities which should not exceed 10% of  its cooling capacity if produce is not pre-cooled

There  are several methods that can be chosen to pre-cool produce. Which  method is the most suitable choice depends on various factors of which  some are listed below:

· Produce characteristics: characteristics  of produce, such as chilling sensibility or the need for rapid heat  removal, lead to differing cooling requirements making methods more or  less suited. Products also differ in their flow capacity; the faster  products can be cooled down, the better. Some methods cannot be  tolerated by some fruits and vegetables, e.g. if they cannot get in  contact with water

· Packaging: the way produce is being packaged makes precooling methods more or less suitable

· Scale: size of operations/amount of produce to be cooled

· Efficiency: depending on the circumstances some methods will be more energy efficient than others

· Skilled labor:  methods require various levels of skilled and trained personnel. The  availability of such trained personnel has to be considered

· Economic viability: the  price of precooling methods differ and have to be considered. This is  true with regards to investment as well as running costs, e.g.  electricity. In general, the cost of the pre-cooling method has to  justifiable with regards to product volume and the increase in product  value in order to make economic sense.

Regardless  of which method is used, the process should always be monitored in  order to ensure that precooling is achieved in the most efficient way.  Depending on method and product at hand, produce will cool at different  rates.

Cold Storage

Roughly  30% of food that is consumed in developing countries is  perishable. Cold storage facilities are crucial to minimize post-harvest  losses; however, losses occur at every step in the post harvest cycle,  and therefore cold storages cannot be considered as independent  solutions to prevent post harvest spoilage but as one component that  needs to be integrated in a cold chain network from the point of harvest  to the point of purchase by the end consumer.

· The different stages in the post-harvest cycle can be summarized as:

· harvest

· precooling

· transportation & packaging

· cold storage

· display at the market

During  these different stages, not only temperature control, but also proper  and minimal handling of produce including handling, cleaning, sorting  and adequate packing is crucial.

Additionally,  socioeconomic factors add to the post harvest loss issue: the lack of  marketing systems, transportation facilities and market information are  key hindering factors. Also, government regulation, often intended to  keep prices low for consumers or to ensure a certain minimum price for  farmers, can be counterproductive regarding incentivizing the production  of high quality produce. Often, simply the required equipment, such as  harvesting tools, containers, cleaning, packing and cooling equipment  are not available. Furthermore, the knowledge on post harvest handling  and marketing of farmers and other actors handling the produce, for  example during transport, is generally very limited leading to  suboptimal treatment of the produce.

Source:Energypedia

https://energypedia.info/wiki/Cooling_for_Agriculture

References

1.   FAO Policy Brief. The Case for Energy-Smart Food.

2.  Cleland  D, 2010. Towards a sustainable cold chain, 1st International Cold Chain  Conference, International Institute of Refrigeration, Cambridge, UK.  March.