Bananas are the UK’s most popular fruit. On average we each eat 10kg of bananas every year (about 100 bananas). There are hundreds of edible varieties that fall into two distinct species: the banana and the plantain banana.
Bananas have a distinct shape and a firm but creamy flesh inside a thick, inedible peel. While people think of bananas as having yellow skin, their colour changes from green (underripe) to yellow (ripe) to brown (overripe).
Although it looks like a tree, the banana is actually a plant. The banana plant grows up to 15 metres and belongs to the same family as the lily and orchid. Bananas grow in clusters of 50-150, with individual bananas grouped in bunches known as ‘hands’ of 10-20 at a time.
The most popular type of banana is the large, yellow, smooth-skinned variety of sweet banana. This banana Musa sapienta varies in size and colour and is usually eaten raw. The larger, green bananas are known as plantains. Plantain bananas are prepared in a similar way to vegetables in that they are usually cooked or fried.
Bananas are an excellent source of potassium and supply vitamin B6, fibre and carbohydrate, and some vitamin C. Since they have a lower water content than most fruit, bananas typically have more calories as well as a higher sugar content compared to other non-tropical fruits.
A 100g serving provides 81kcal, 20.3g of carbohydrate, 1.4g fibre and 18.1g of natural sugar.
Unripe bananas have a higher starch content. As they ripen, the starch is converted to sugar (and the fruit becomes sweeter). Green bananas are also a good source of pectin, which is a type of dietary fibre found in fruits and helps them keep their structural form. Pectin breaks down when a banana becomes overripe, which causes the fruit to become softer.
Bananas are loaded with valuable micronutrients, especially potassium. Potassium is one of the most important electrolytes in the body, helping to regulate heart function as well as fluid balance – a key factor in regulating blood pressure. The effectiveness of potassium-rich foods such as bananas, in lowering blood pressure and protecting against heart disease and strokes is well accepted and bolstered by considerable scientific evidence.
Bananas are soothing to the gastrointestinal tract due to their high content of pectin – as soluble fibre that not only lowers cholesterol but normalises bowel function. The high fibre content of bananas promote satiety (feelings of fullness).
The resistant starch in bananas also has a prebiotic effect, helping to fuel the gut bacteria so they increase their production of short chain fatty acids which are beneficial for digestive health.
Did you know?
The inside of a banana skin can be used to calm an itchy mosquito bite – many people find that rubbing the bite with the skin helps to reduce irritation.
Select and store
Bananas and plantains are picked underripe and transported from the tropics and set to ripen on the supermarket shelves or in our fruit bowls. Those with green tips are not quite ripe, but they will continue to ripen if stored at room temperature, particularly if placed in a plastic or paper bag as the gases they emit stimulate further ripening (and can ripen other fruits they are placed with).
When bananas have light speckles of brown on their skins it is a sign they have ripened naturally. When buying plantain, choose those with skins that are neither yellow nor too brown.
Bananas are grown in hot climates, so they do not naturally like the cold. If kept in the fridge, the enzymes that cause them to ripen are deactivated. Instead you might find the skin blackens. Although if you prefer an underripe banana you might want to keep them in the fridge.
Bananas freeze well. Peel the skin off first and put them in a freezer bag. Frozen bananas can be blended in a food processor to make a delicious dairy-free ‘ice cream’ or pop them in your blender for a cool and creamy addition to a smoothie.
As well as being eaten raw, bananas are a great addition to a variety of recipes including smoothies, baked goods and cereal where you are reducing the amount of refined sugar. Unlike bananas, plantains cannot be eaten raw – they need to be cooked. They can be grilled and then mashed into porridge or more commonly roasted or fried. Mostly viewed as a sweet fruit, some Asian cuisines treat bananas like a vegetable and use them in savoury dishes too.
This article was updated on 1st November 2019 by Kerry Torrens.
Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.
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