Market Requirements
At harvest, bananas destined for export need to be free of significant bruising, blemishes and foreign matter such as insects or dust. Bananas are largely graded into one of three classes, ‘Extra’ ‘Class I’ or ‘Class II’.
Maturity standards vary between countries or regions and the length of time the fruit is to be in transport and storage. Fruit is usually harvested when it is light green and the ridge corners of the fruit have turned from an angular to a rounded shape. Harvesting too early can result in fruit that loses weight in transport and takes too long to ripen. Conversely, harvesting overripe fruit will lead to significant breakdown, rotting and reduced shelf life.
The banana fruit is harvested fully mature for immediate ripening and consumption in local markets. For short distance markets, fruit should be harvested at 90% maturity and for longer distance transportation, 75% maturity is the norm. 75% maturity is when the fingers are 3/4 round, i.e. they still have pronounced ridges running the length of the fruit, but the fruit surface is convex. Various qualitative methods have been developed to test for maturity, e.g., pulp to peel ratio and skin firmness index, but the best, most practical field method is to harvest at a set date following flowering.
A quick field check of maturity may be made by immersing a cut banana in iodine, the darker the staining of the pulp, the higher the level of starch/sugars. Bunches are checked for maturity at the processing station. The pulp and skin of the cut fruit needs to be firm, and the pulp a creamy buttery consistency and uniformly yellow in color. The ‘seed’ color should be brown and there should be latex draining from the cut peel.
In the tropics, average date from flowering to harvest varies between 90-115 days. Thus, once fruit approaches the appropriate maturity date for the region, bunches are regularly checked for size and shape, to determine correct time of harvest. At this stage, fruit is cut when the middle finger on the outer whorl of the second hand is between 31-41mm in diameter. However, within this size range, the USA market prefers slightly larger diameter fruit than Europe.
Storage during shipping is at 14.5°C and the temperature and humidity conditions are closely monitored throughout the voyage. Ripening takes place in cooled stores with temperatures of between 14.5 and 18°Cand under controlled humidity conditions usually > 85% RH. Ripening programs usually run from between 4 to 8 days and aim to produce fruit of a bright consistent skin color before retailing.
