New building houses a bunch of bananas

Press, 18 July 1979, Page 15

New building houses a bunch of bananas

A banana-ripening complex might not be everyone’s idea of a sound business investment, but to Macfarlane and Growers, Ltd, it means a revolution in the storage and marketing of this important fruit. Bananas are an unusual commodity to handle. They are picked green in their native Ecuador, transported halfway around the world in cold storage and then encouraged to ripen on arrival. Taking into account the fact that it takes only four days to turn a green banana into a ripe banana, the whole operation is rather tricky. In a strictly-controlled environment, however, bananas can be ripened or kept “on ice” almost at will. Previously, insulation for the fruit was provided by thick cork-lined concrete walls, But even a slight variation in temperature could cause a catastrophe. Once bananas start to ripen, the process is uncontrollable, resulting in market saturation with over-ripe, consumer-re-sisted fruit. The new storage rooms at Macfarlane and Growers will combat all that. A $650,000 protect, the build-

ing has a gross area of 1654 sq. m„ most of which is taken up by 14 banana ripening and cool storage rooms. Design of the building was undertaken by Mr M. J. Morrow of Campbell, Hamann and Partners, Consulting Engineers. Although outside the building appears unremarkable, modern technology has worked magic with the interior. Research into insulation has found a polystyrene material strong enough to build walls with, light enough to be easily handled, very hygienic and totally insulating. The banana rooms are built completely from this material, which is only 8 cm thick. Each room operates independently to a controlled temperature between minus 30 degrees and plus 30 degrees celcius, according to the needs of its banana inhabitants. The Plant Room which controls all these programmes looks for all the world like a miniature power station, with rows of neat, new and symmetrical machinery which hums, clicks and whirrs as different demands are made on it. The Plant Room gives individual control to each of the ripening rooms, increasing or decreasing the temperatures as it becomes necessary, turning on heating coils or refrigeration units to suit. When a shipment of bananas arrives in port, the cartons are placed on pallets at the ship’s side and brought directly to the ripening complex by road. A forklift transfers the

cartons to the banana rooms, where they are stacked in a special formation. The whole operation must be completed with no time wastage and the trucks that bring the bananas are covered, summer and winter, to prevent temperature variations causing havoc with the loads.

Once safely inside the rooms the cartons are stacked in a honeycomb pattern, 15 long and eight high, leaving space between each box to allow greatest air circulation. This is a scientific formation proved to be the most effective in terms of practicality, air volume and flow, and use of available space. If the bananas are to he ripened for immediate sale, the rooms involved are pre-heated to a temperature of 22 degrees cel-

sius. This temperature level is maintained until the fruit of the bananas, or pulp, is heated to between 19 and 21 degrees. When the pulp reaches the required temperature, usually after about 18 hours, a special ethylene ripening gas is introduced and continues to flow through the room for 24 hours. By this stage the bananas have started to ripen. An intricate ventilation system in each ripening room allows air replacement within a few minutes. The doors let fresh air in, and an exhaust tunnel in the ceiling removes gases and impure air almost instanteously. After the gas treatment the air inside the rooms is changed twice every day, and the temperature of the banana pulp is measured with a hyperder-

mic-like thermometer. There is. a fine line between producing ripe bananas for market requirements on the right day and producing a batch that is less than perfect. Practical experience is the main factor involved in successful banana ripening, but this is not enough without a back-up knowledge of the ripening equipment, which must be used intelligently to produce the best results. Macfarlane and Growers’ new complex can be used equally for banana ripening and for storing unripe fruit for relatively long periods. Modern techniques have given them the best facility in New Zealand, and one of the., best in the Southern Hemisphere, for the safe, scientific and effective ripening of bananas.