INCORPORATING COLD CHAIN
TECHNICAL
© Cold Link Africa
The presentation on grapes was suitably delivered in Stellenbosch .
into reefer containers , as the container ' s primary function is to maintain temperature rather than to cool the products .
“ Ensuring that pallets are not packed tightly against the container walls can prevent heat transfer from the container walls to the product . Additionally , covering the entire floor with pallets ensures even distribution of airflow .
“ Continuous monitoring of temperature and other factors such as humidity and respiration rates is crucial . Even minor , frequent temperature deviations can significantly impact product quality .
“ Incorporating advanced airflow technologies like Airflo and RAFT can substantially improve temperature management within containers , thereby maintaining product quality and reducing claims ,” she says .
The cold chain industry must continuously innovate to meet the growing demands for high-quality , temperaturesensitive products . “ Our study on table grapes demonstrates the tangible benefits of adopting new airflow technologies to enhance efficiency and product integrity in cold chain logistics . By integrating these advanced solutions and adhering to best practices , stakeholders can ensure that perishable goods reach their destinations in optimal condition , thereby reducing losses and improving profitability ,” says Gerber .
THE LINK BETWEEN RESPIRATION RATE AND SHELF LIFE
“ Fruit , being a living entity , has a respiration rate that is directly linked to its lifespan . Managing this respiration rate through optimal temperature control can significantly extend the lifespan of the fruit , ensuring that table grapes reach their destination in peak condition . Proper temperature management not only extends shelf life but also improves overall quality , reducing spoilage and financial losses . “ We began our research with an extensive review of existing literature to build on previous findings and avoid redundant efforts . We consulted with cold storage facilities and were present to place the temperature monitoring devices ourselves when the pallets were loaded into the reefer containers . We also conducted interviews with industry experts , all with over ten years of experience in the table grape sector , to gather their insights on best practices and challenges ,” she explains .
“ We accessed quality reports for all six containers of table grapes
upon arrival in Rotterdam to correlate temperature profiles with any quality issues . The temperature sensors tracked both ambient and pulp temperatures throughout the journey . Sensors were placed in strategic positions within the containers to capture comprehensive data : positions L1 , R1 , L6 , R5 , L11 , and R9 in the bottom and middle layers . Additionally , both RTM sensors and CL60 Amphenol sensors were used , along with probe sensors inserted into grape berries to measure pulp temperature .
• Airflo floor covering : Two containers were fitted with Airflo floor coverings , trapezoid-shaped pieces designed to enhance airflow . These were placed from the back of the container ( near the refrigeration unit ) forward , accommodating two pallets per piece . The installation time for the Airflo kits was recorded for efficiency analysis .
• RAFT kit : This technology involved covering the T-bar floor with a plastic sheet from the back of the container up to three metres from the doors . Styrofoam blocks were attached near the refrigeration unit , and cargo panels were placed around pallets to direct airflow and prevent shortcuts . Collapsible cardboard panels were also used to control airflow over the pallets . The RAFT kit installation process was also timed and recorded .
Upon arrival in the Netherlands , the temperature sensors were retrieved and the data downloaded into a single Excel file for analysis . “ Although the arrival warehouse did not document ( as instructed ) when the sensors were removed , a clear temperature increase in the data allowed us to pinpoint the removal time accurately . We divided the cold chain journey into five stages : cold store origin , Port of Cape Town , sea leg , destination port ( Rotterdam ), and arrival warehouse .”
VISUALISING TEMPERATURE PROFILES
“ Using software tools such as Statistica 14 for data analysis and Tableau Desktop for visualisation , we analysed temperature profiles . The figures showed the median temperatures across all sensors and shipments .
• First shipment : The temperature profiles revealed a significant spike towards the end of the cold store stage , indicating when pallets were transferred into containers .
COLD LINK AFRICA • September 2024 www . coldlinkafrica . co . za 31