A recently published paper [Remote Quality Monitoring in the Banana Chain, Jedermann et al; Philosophical Transactions A 2015; 373(issue2038)] provides a novel approach for the control of quality problems in the transportation of bananas.
The authors present different models to predict the effects of the atmosphere in the storage stability of banana, as well as to evaluate the cooling efficiency, packaging and stowage in the amount of respiratory heat produced.
“Quality problems occurring during or after sea transportation of bananas in refrigerated containers are mainly caused by insufficient cooling and non-optimal atmospheric conditions, but also by the heat generated by respiration activity. Spontaneous ripening causes higher respiration heat and CO2 production rate. The resulting risk for creation of hot spots increases in positions in which the respiration heat exceeds the available cooling capacity”.
“Bananas are very sensitive to ethylene. The ethylene emission of one pallet load in a poor-quality state can initiate spontaneous ripening of the full container load. The response to ethylene depends on fruit maturity, exposure time and temperature.
- At 15°C, ripening of green ‘Cavendish’ bananas is initiated with 0.1 ppm of ethylene in air for 2 days.
- At 20°C with 0.1 ppm ethylene, fruit ripening is initiated already after 20 h”.
“The start of ripening is accompanied by an increase in ethylene production from 0.15 μl/kg−1 h−1 to 5 μl/kg−1 h−1 at 15°C, thus leading to an autocatalytic effect as the following example calculation shows: one 18 kg box of yellow bananas produces within 2.2 days sufficient ethylene to increase the concentration in the whole container with a free air volume of 47.4 m3 to a critical threshold of 0.1 ppm, if the air flaps are closed, and no ethylene is released to the ambient”.
“The ethylene production of single fruits can increase owing to mechanical stress or fungal infections. The autocatalytic effect has to be considered for the whole container load and not individually for single boxes, because the polyethylene packaging is semi-permeable to ethylene gas”.
“The efficiency of cooling can be greatly improved by better packaging and stowage. For the standard packing, only 10% of the available cooling capacity actually affects the fruit inside the boxes. We showed that the air flow and therefore the cooling capacity could be improved by up to 50% through changes in packaging and stowage pattern”.