January 20, 2014

Cold Chain First: Key Factors to Succeed


The importance of keeping the cold chain linked tightly to ensure quality and protection of perishable cargo can never be taken for granted. Proper cargo management and safety procedures within the cold chain from harvest through delivery are essential to protecting the industry, consumers and profits. In this issue of 20/40, Gino Ansaldi, sales and service manager for Thermo King Marine, offers a refresher on the concepts and importance of a closed cold chain, specifically in pre- and post-harvest techniques.


“Today’s expectations are high in regards to product quality and enhanced shelf life,” explained Ansaldi. “The technology and performance of modern refrigeration equipment have allowed amazing opportunities around the world in terms of exports and imports of fresh commodities. However, it is important to note, that even the best container reefer in the world cannot erase damage done due to incorrect pre- and post-harvest handling. This is a training area that Thermo King believes strongly in supporting to ensure customer success and profitability.”

Pre-harvest Techniques

 A key factor of perishable produce transportation, pre-harvest techniques involve proper land utilization, appropriate watering or irrigation and proper fertilizers and management. In addition, harvesting products at the right time is crucial. The produce must be of right maturity and it should be picked in the early morning, when ambient temperatures are coolest.

Post-harvest Techniques

Pre-cooling Vital to Extending Shelf Life:  Pre-cooling, proper packaging and effective, temperature-controlled transportation of products throughout the cold chain are all key factors in extending a product’s shelf life. Depending on the region and scope of operation, pre-cooling techniques can vary greatly in size, expense and methodology. Some options include forced air with a cooling tunnel or cold storage facility; hydro-cooling, which utilizes cold water to remove heat from sensitive products like cherries.

Cooling produce down quickly after harvest is vital to slow down the respiration of produce. Certain fresh commodities such as apples, kiwi, bananas and cantaloupe, continue to respire after harvesting. Low oxygen (O2) levels will slow down the ripening process for most of these fruits, which are known as ‘climacteric.’ Some fruits, such as oranges, strawberries and watermelon, are known as ‘non-climacteric.’ High carbon dioxide (CO2) levels have an anti-bacterial and anti-fungal effect on some of these fruits. It is important to understand the attributes of each commodity, respiration rates and necessary shipping parameters to ensure the longest life possible. Most importantly, shippers need to remember that heat is always the enemy.

Strict Loading Techniques that Preserve Product Quality:  Correct loading practices are conducive to proper airflow and circulation. Paths on all six sides of the load should be free from obstruction. There should be no open floor space at the front or end bulkhead or side walls of a container. Cargo should NOT be loaded to the ceiling; red line limitations should always be respected. Cargo should be stacked on double-faced block pallets. Weight should be evenly distributed in the container for maximum stability. If cargo is palletized, place dunnage or air bags in center channel between panels. Other factors to consider in achieving optimum airflow include keeping floor under the load free from obstructions, cleaning container before loading, and ensuring T-Floor is free of debris (i.e. shrink wrap, paper) as this can block air circulation or be sucked into evaporator fans.

Contact your Thermo King dealer or representative if you have questions or would like to schedule a specialized training on this topic. Look for Part II of Gino’s refresher course on the Cold Chain in the next edition of 20/40. 

Packaging that Protects … and Vents: Proper packaging and loading techniques are crucial for preserving quality. Vented-side, crush-proof packaging should always be used for fresh products as opposed to solid side packaging for used for frozen products. Packaging must be properly designed, constructed and stowed to protect the product from rough handling, overloading and moisture loss. Ventilation must be incorporated into the packaging of fresh products to allow proper temperature management and control.

Quick Fact: Poor air distribution is one of the primary causes of product deterioration, even when unit capacity is more than adequate. Obstructions anywhere around the load can result in product ‘hot spots.’

In addition, the product must be pre-cooled to optimal temperature before loading. Check product temperature during loading. Reefer units are designed and optimized to maintain product temperature, NOT LOWER IT.

Quick Fact: Human errors account for more than 80% of lost loads in the container industry. Improper pre-cooling and cargo loading practices make up 34% of this number.