In some countries tomatoes are picked when they change colour from green to the initial stage of ripening. For better flavour, tomatoes should be harvested after the colour has changed completely.
Plant nutrients, climate, fruit management, pre- and post harvesting temperatures as well as logistics all affect the shelf-life of tomatoes. Decades of cultivation have resulted in the adaptation of new generations of tomatoes that are firmer and last longer.
In some countries tomatoes are harvested when the fruit are at the stage of mature green to the start of colouring. This is because consumers still think that red tomatoes are overripe. They don’t realise that it is possible to harvest ripe fruit without making a difference to shelf life.
Picking tomatoes when they are red to full ripe helps to unlock the full taste and colour potential of these fruit. Picking these new improved tomatoes at the wrong stage of ripeness result in them losing their inherent keeping ability.
Other factors such as time and distance from the market as well as cold chain management also play a role. The temperature must be kept constant within certain limits while the crop is on its way to its ultimate destination.
SIGNS OF MATURITY
The size of the fruit is seldom an indication of the degree of maturity, because some cultivars bear bigger fruit than other cultivars. There are seven identification and marketing classification stages in the ripening process of tomatoes, namely:
- mature green
- first stage of colouring
- half ripe
- red ripe
- full ripe
There are 6 size gradings:
- cherry (smaller than 30 mm in circumference)
- small (smaller than 35 mm)
- medium (56 mm to 73 mm)
- large (73 mm to 82 mm)
- extra large (83 mm to 94 mm)
- extra extra large (95 mm and larger)
FACTORS TO CONSIDER
The stages of mature green to the start of colouring come just before the fruit begins to ripen to light red or the so-called champagne colour. The inside of the fruit has then already started to change colour.
Some farmers are far away from markets, so this is the stage of ripening when they normally pick.
These fruit will change colour from the under ripe stage to the ripe stage while being transported to the markets. If there are low temperatures at this stage, the tomatoes will only change colour when they reach the market. The fruit starts to change colour at the blossom (flower) end, or on the side that gets the most sunlight.
At the under ripe stage, the colour of the fruit has changed to light red. This is the stage at which some consumers buy their tomatoes.
If the farmer gets an indication that rain or inclement weather is on its way, this can be the appropriate stage at which to pick tomatoes, because these conditions are beneficial for the slow change in colour.
BEST FLAVOUR AND TASTE
The best time to buy tomatoes is when tomatoes are ripe or fully ripe. At this stage the fruit not only shows off to best advantage, but the flavour is also at its best. The highest possible sugar content can be expected in the fruit at this stage.
Tomatoes destined to be used in the factory for the manufacturing of tomato paste, are harvested when they are ripe or fully ripe. If picked at this stage of ripeness, new-generation tomatoes having a long shelf life can retain quality for three weeks or longer.
Farmers should always remember that the quality of the product goes hand in hand with profitability.
The information and photographs were supplied by Starke-Ayres.