Food, Nutrition & Science

from our newsletter, broadcast on
Sunday December 30, 2007

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Bananas

Seasonal

Bananas
SEASONAL
Bananas
With Jack Frost nipping at our noses up here in the Northern Hemisphere, it’s hard to imagine a place where tropical breezes still warm the soul. But thanks to the position of the sun’s rays, temperatures are always hot close to the equator. It is in this warm, moist climate that bananas make their home. Sweet, soft and season-less – they are available year round – bananas are a good source of vitamin C, potassium and dietary fiber.
 
Bananas have been in cultivation since recorded history began. Some horticulturists believe that bananas could have been the Earth’s first fruit. Officially introduced to Americans at the 1876 Philadelphia Centennial Exhibition, bananas have become the most widely consumed and popular fruits in our country.
 
Bananas don’t grow on trees. They grow on plants that are related to the lily and orchid family. Bananas need temperatures around 80°F, an annual rainfall of about 79 to 98 inches, moist soil and good drainage. That means most bananas are grown between 30 degrees North and 30 degrees South latitude. As the largest plants on earth without a woody stem, banana plants are fragile and require intense care – including the clearing away of jungle growth, and propping to counter bending from the weight of heavy fruit.
 
Reaching its full height of about 15 to 30 feet in one year, banana plants only bear one stem of fruit. Two new stems – known as the daughter and granddaughter – can be cultivated from the main plant. At harvest, when the bananas are still green, stems average 150 “fingers” or single bananas. Groups of bananas growing together are called “hands.” Once the main stem is removed, the remaining daughter and granddaughter stems become the main plant, repeating the cycle of growth.
 
Post harvest, bananas are removed by hand, then cut into smaller clusters. Clusters are washed in moving fresh water, and after examined for quality control. Heat and humidity speed up the ripening process, so bananas must be maintained at 58 degrees Fahrenheit during shipment. Once they arrive in North America, they are ripened in a controlled environment. Many bananas are ripened artificially with ethylene gas – a substance that triggers maturation.
 
One of the few fruits that ripen off the plant, bananas sweeten considerably as the starch inside the fruit converts to sugar. The color of the peel is the ultimate determining factor for a bananas readiness for market. On a scale of 1 to 7, with 1 being hard green, and 7 being flecking and brown, most bananas ship to retailers at color stage 3.5 (more green than yellow). Interestingly, bananas can be stored in the refrigerator until desired ripeness is achieved. Even though the skin will turn brown, the fruit inside will be delicious and not over ripe.
 
There are hundreds of varieties of banana plants, though not all produce bananas. Some produce no fruit at all, and some produce plantains, which are starchy and taste more like squash or potatoes. The main store varieties include Cavendish bananas – the commercial variety available in most local supermarkets, Dwarf or Finger bananas – smaller versions of the Cavendish, Apple bananas – a short, plump variety with an apple taste, and Red bananas – sweet, chunky, creamy bananas with a red skin that turns purple when ripe.
 
On average, Americans consume over 28 pounds of bananas each year, with over 96% of households purchasing bananas at least once each month. That’s why it’s hard to believe – especially in light of these numbers – that the future of the banana is actually extremely uncertain. Since each banana is a genetic duplicate of the next, the fruit is extremely susceptible to blight.
 
The Cavendish, the most well-known variety, is currently battling a blight called Panama Disease, for which there is no cure. The disease has already ravaged the crop in many Asian nations, including virtually all the crop in Malaysia. It has even spread as far as Australia. Although the disease has not yet reached Latin America, which supplies all of the bananas we eat in the U.S., it could appear here within the next 20 years.
 
The good news for retailers is that the blight does not affect fruit that has come to market, and it cannot sicken ordinary people. It also doesn’t affect a grocer’s ability to keep bananas fresh. Still, Dan Koeppel, author of the recent release Banana: The Fate of the Fruit That Changed the World, says that it’s a race against time to save the world’s most beloved fruit.
 
“This is not an immediate problem for grocers, but it is indicative of the globalization of the fruit trade. Disease can spread easily in this global market,” says Koeppel. “The effort to make a disease resistant banana that tastes right, ripens properly and transports well is a huge challenge, and may eventually require genetic modification or a switch to another variety.”
 
This isn’t the first time that bananas have faced such a threat. For the first half of the 20th century, consumers enjoyed a banana known as the Gros Michel. By the 1960s, however, the entire crop had been devastated by the same Panana Disease that is now threatening the Cavendish variety. Eventually, the more disease-resistant Cavendish moved in to replace the now extinct Gros Michel. But recent strains of Panama Disease, found in Asia over the last 15 years, can infect the Cavendish – and wipe out an entire country’s banana crop in just five to 10 years.
 
“Real concern exists for those who rely on bananas for almost all of their daily nutrition. In some parts of Uganda, people eat up to 900 pounds of bananas per year,” says Koeppel. “The reality is that within the next 50 years, we’re likely looking at a completely changed industry.”