I like to grow my own food, particularly tomatoes. I find that the ones I grow myself are much sweeter and less watery than the ones I get from the supermarket. I particularly like a variety called Ailsa Craig.
Over at Not Exactly Rocket Science they’re revealed the reason and it turns out to be genetics.
Over the years tomatoes have been selectively bred to look good and keep for a long time on the supermarket shelves. Farmers have been picking those tomatoes with these properties and cross breeding them, disposing of any offspring that don’t show this trait. The tomatoes have got rounder and redder and they certainly keep for longer, but what’s most important is they ripen uniformly.
In my garden tomatoes the whole tomato doesn’t turn red at once. The unripe tomatoes have a darker green part at the top and a paler part at the bottom. The red then develops unevenly across the fruit. The dark green is what is responsible for the sweetness of my tomatoes.
The green is caused by the presence of chloroplasts (and the pigment chlorophyll) in the fruit. The darker the green, the more chloroplasts are present. In chloroplasts, the process of photosynthesis is occurring. This is the process by which plants turn carbon dioxide and water into sugar and oxygen.
Darker green = more chloroplasts = more photosynthesis = more sugar in the fruit.
What do we need to do to make supermarket tomatoes taste better?
Simples! We could use genetic engineering to add the gene for the dark green pigment to the tomatoes, thus making them sweeter.
Or we could all just grow our own and reduce our carbon footprints…