TECHNICAL
• Second shipment : In the control container during the sea leg , temperatures were not uniformly maintained , indicating variability and potential risk to grape quality .”
Breaking the cold chain into five stages provided valuable insights :
• Cold store origin : Ensuring precise precooling is critical as containers cannot lower the product ' s temperature .
• Port of Cape Town : Efficient handling and minimal exposure to ambient conditions reduce temperature spikes .
• Sea leg : Maintaining consistent temperatures during transit is crucial for product integrity .
• Destination port ( Rotterdam ): Swift unloading and appropriate storage facilities at the destination are essential .
• Arrival warehouse : Proper documentation and handling at the final destination ensure the quality of the grapes .
“ Our study demonstrates that innovative airflow technologies , such as Airflo floor coverings and RAFT kits , significantly improve temperature management within reefer containers , thereby enhancing the quality and shelf life of table grapes during longdistance transportation . By integrating these technologies and adhering to best practices , the cold chain industry can better meet the demands for high-quality , temperaturesensitive products , reducing spoilage and improving profitability . This research provides a foundation for further advancements in cold chain logistics , paving the way for more efficient and reliable transportation of perishable goods ,” adds Gerber .
“ During the cold store stage , the highest temperatures were recorded in all three layers of the container fitted with Airflo , while the coolest temperatures were found in the container fitted with RAFT . At the origin port , the highest temperatures were noted in the control container , while the coolest temperatures were measured in the
Supplied by John Ackermann
Table grapes , known for their sensitivity , require precise temperature management .
top layer of the container fitted with Airflo and in the middle and bottom layers of the container fitted with RAFT .
“ We defined a temperature break as any instance where the temperature fell below -1.5 ° C or rose above 2 ° C for longer than 90 minutes . We further distinguished between sensor breaks ( single sensor deviations ) and container breaks ( two or more sensors showing deviations ).”
KEY FINDINGS
• Origin port : This stage had the most container temperature breaks , particularly in the control containers during both shipments . The control containers exhibited the highest temperatures , likely due to delays and exposure at the port .
• Sea leg : Significant temperature breaks were also observed during the sea leg , especially in the control containers . The one vessel had more temperature breaks compared to the other vessel , indicating variability in temperature control during transit .
• Sensor positions : Pallet position R9 , closest to the container doors , consistently recorded the highest temperatures across most stages , indicating that this position is more vulnerable to temperature fluctuations . This was particularly evident in the control containers .
• Quality reports : Quality assessments revealed that control containers received poor scores ( 4 ), primarily due to high levels of decay , berry cracking , and sulphur dioxide bleaching . Containers with Airflo received scores of 3 to 4 , while those with RAFT generally performed better , except for one variety which scored 4 to 5 due to berry cracking , sulphur dioxide bleaching , and skin defects .
CHALLENGES AND RECOMMENDATIONS
The study highlighted several challenges and provided recommendations for improvement :
• Cold store and origin port : Insufficient pre-cooling capacity and improper loading practices contribute to temperature spikes . Training workers to load pallets correctly and ensuring
sufficient cooling capacity are essential .
• Port operations : Delays due to equipment inefficiencies , labour issues , and paperwork handling at the Port of Cape Town result in prolonged exposure to ambient temperatures . Addressing these operational inefficiencies and ensuring quick connection to power sources can mitigate temperature rises .
• Sea leg : Long temperature breaks during the sea leg are likely due to containers being unplugged too early at the port . Ensuring continuous power connection until the containers are loaded onto the ship is crucial .
• Hotspots in storage : Both cold stores and reefer containers have hotspots . Rotating pallets within cold stores and ensuring proper airflow in containers can help maintain uniform temperatures .
• Installation of Airflo technologies : The time required to install Airflo is about 10 minutes less than RAFT . However , correct installation is vital for these technologies to function effectively .
“ The introduction of airflow technologies significantly improved temperature management within reefer containers . While RAFT performed slightly better than Airflo , the small sample size necessitates further trials to confirm these findings . Addressing the identified challenges , particularly at the cold store and origin port stages , can enhance the overall efficiency of the cold chain and reduce temperaturerelated quality issues . Our findings provide valuable insights for the table grape industry , emphasising the importance of precise temperature control and operational efficiency to maintain fruit quality during long-distance transportation .
“ This study serves as a foundation for further research , encouraging the adoption of innovative technologies and best practices to improve cold chain logistics for perishable goods ,” concludes Gerber . CLA
32 www . coldlinkafrica . co . za COLD LINK AFRICA • September 2024