By: Hamburg Süd
Whether in a smoothie, in a salad or on a sandwich – the appetite for avocados is growing worldwide. The fresh products are transported in reefer containers from their countries of origin to their destination. During the journey, temperature-controlled air must be circulated both around the fruit inside the carton and throughout the entire load to remove respiratory heat, water vapor, and gases such as carbon dioxide and ethylene. To make sure that this happens, the right stuffing method is key.
Reefer containers are equipped with bottom air supply: temperature-controlled air is forced down the bulkhead and blown in at the bottom of the refrigeration unit through the gratings in the ducted floor, or T-floor. “Air always takes the path of least resistance,” explains Michaela Steineker, State Certified Food Chemist and Head of Reefer Competence at Hamburg Süd. If air gaps or chimneys are left in the stow, they provide an easier route for airflow than that through the cargo. “The avocado pallets must therefore cover the entire T-floor to ensure proper distribution of temperature-controlled air.” Where the pallets do not cover the entire T-floor, some type of filler material, e.g. heavy cardboard, must be placed wherever there is no cargo.
It is referred to as bottom blocking when the open T-floor and the front face of the last pallets at the door-end are covered. Another possible method to ensure the required airflow through and around the avocado cartons is top blocking, where cardboard is instead placed at the top of the last pallets, between the last carton row and the container ceiling. If properly secured, a top blocking should be preferred as it provides increased airflow between the cargo and the doors and can therewith further reduce the exposure to hot or cold ambient temperatures.
One method of blocking at the door end, either bottom blocking or top blocking, should be used – however, they should never be used both at the same time.
Attend to the World Avocado Congress and learn more about the industry of the avocado. September 23 to 27 in Medellín, Colombia.