Energy content of ripe vs unripe fruit

Factual Questions
1

I was pondering this while eating a banana. I prefer the taste and texture of slightly under-ripe bananas – over-ripe ones I find too sweet and cloying. But does the calorie content of the fruit increase as it ripens?

My first thought was, of course it does – the ripe fruit is sweeter, it obviously contains more sugar. But then I thought, well how can it? Where would the extra energy come from? The fruit is no longer photosynthesising as it sits in the fruit bowl. Presumably the whatever-it-is that turns into sugar as it ripens is already there in the fruit in another form. But what form? Starch?

Then I got confused, and ate another banana, but I was still none the wiser.

What sayeth the Dope?

2

Yes, it’s the starch in bananas that turns into sugar in the ripening process. And yes, that means the fruit has slightly more calories when ripe.

3

One first consideration would be: are you asking about total energy content when burnt to ashes, or calories that your body can use?

4

Both. But mainly energy that can be used by the body.

5

Cite? The fruit has the same amount of carbs in either form. Some have just been converted to sugar.

Unripe fruit may need to be chewed more thoroughly to ensure maximum absorption, but I don’t see how the calorie count would change significantly.

6

Doesn’t sugar have the same number of calories per gram as any other carbohydrate - 4?

7

Neglecting the energy used by the banana during the ripening process, the energy content is about the same, as long as the banana ripens after being picked. Starch is hydrolyzed to sugar in the digestive track

8

Don’t forget the metabolic cost of digesting the food. It takes energy to break down the nutrients, which can affect the net calories available to you. It’s not much in this case, but it’s still worth mentioning.