My garden is full of small, green tomatoes hopefully on their way to becoming larger, red tomatoes. In another word, ripe.
Today’s Saturday Swot Shop looks at the ripening process and its key component Ethylene.
When the fruit of a plant ripens what changes are taking place ?
- A fruit can be mature in size but not ripe. Ripe is the final stage of maturation and is when the colour, texture, flavour and aroma of a fruit all come together to make it ready for eating.
- The change in colour is due to the decrease in chlorophyll and the increase of carotenoids, in the case of tomatoes, lycopene, which is red in colour. Also changing are the cell walls which start to degrade and so make the fruit softer, the sugar/ acid balance and the change of starches to sugar which impacts on the flavour.
- All these changes are brought about by the release of Ethylene.
What is Ethylene ?
- A plant hormone that takes the form of a hydrocarbon gas. The tomato belongs to group of fruits called Climacteric. Climacteric fruit include melons, avocados, apples, peaches, pears and bananas. These fruit produce and emit ethylene and can ripen off, as well as on the plant.
So hence why tomatoes can be put somewhere ‘to carry on’ ripening ?
- Yes and you can either wait for green tomatoes to ripen at their own pace or speed things up by making use of another climacteric fruit.
Hence the advice to put mature but green tomatoes in with a ripe banana. A ripe banana especially if spotty, is releasing lots of Ethylene which passes to the yet to ripen tomatoes and accelerates the process.
So the leftover banana isn’t going to waste, it’s a tomato ripening device ?
- Exactly!
