Tomatoes
| Infobox on Tomatoes | |
|---|---|
| Example of Tomatoes |  |
| Freshness facts | |
| Optimum carrying temperature | 12°C to 15°C (mature green) 10°C to 12°C (turning) 8°C to 10°C (ripe) |
| Highest freezing point | -0,5°C |
| Acceptable product temp. at loading into containers | Max. 2°C above carrying temperature |
| Optimum humidity | 90% |
| Ventilation setting for containers | 25 m³/hr |
| Storage life | 1-2 weeks (mature green/turning) 1 week (ripe) |
| Climacteric / non-climacteric | Climacteric |
| Ethylene production | Very low |
| Ethylene sensitivity | High |
| Modified / controlled atmosphere | 3%-5% O2; 2%-3% CO2 (see text) |
| Potential benefits | Reduced O2; reduced ripening, respiration and ethylene production. Increased CO2; delayed ripening |
| Availability | |
| On demand | |
Tomatoes
Contents
Harvesting and Handling
There are four main varieties of tomatoes, viz., Round (spherical), Beef, Cherry and Plum tomatoes.
Depending on the market and production area, tomatoes are harvested at stages of maturity ranging from physiological maturity (mature-green stage) through full-ripe.
Ripeness stages are defined according to the following standards for red-fleshed tomatoes:
Ripeness Stage External Color
(1) Green Fruit surface is completely green; the shade of green may vary from light to dark.
(2) Breaker there is a definite break in color from green to tannish-yellow, pink or red on not more than 10% of the surface
(3) Turning 10% to 30% of the surface is not green; in the aggregate, shows a definite change from green to tannish-yellow, pink, red, or a combination thereof
(4) Pink 30% to 60% of the surface is not green; in the aggregate, shows pink or red color
(5) Light red 60% to 90% of the surface is not green; in the aggregate, shows pinkish-red or red
(6) Red More than 90% of the surface is not green; in the aggregate, shows red color
High quality fruit have a firm, turgid appearance, uniform and shiny colour, without signs of mechanical injuries, shrivelling or decay. Principle causes for postharvest losses are decay, external damage incurred during harvest and handling, and harvest at an improper maturity stage.
Cooling and Storage
Following commercial packing, tomatoes are routinely palletised and cooled to 20°C for ripening or to 12°C for storage. Optimal storage temperatures depend on the maturity stage of the tomatoes. Ideal conditions for ripening are 19°C to 21°C with 90% to 95%RH.
Storage >27°C reduces intensity of red colour, while storage <13°C retards ripening and can lead to development of chilling injury, particularly in tomatoes at the mature-green stage. Red tomatoes can be stored at 7°C for a couple of days; tomatoes stored at 10°C were rated lower in flavour and aroma than those held at 13°C.
Tomatoes are climacteric and show a pronounced increase in respiration during ripening. The intensity and duration of the climacteric varies among fruit species. Respiration also varies with temperatures and atmospheric composition.
Tomatoes are chilling sensitive at temperatures below 10°C (50°F) if held for longer than 2 weeks or at 5°C (41°F) for longer than 6-8 days. Consequences of chilling injury are failure to ripen and develop full colour and flavour, irregular (blotchy) colour development, premature softening, surface pitting, browning of seeds, and increased decay. Chilling injury is cumulative and may be initiated in the field prior to harvest.
Controlled atmosphere considerations
Tomatoes can be stored under CA to extent product quality. The exact combination of CO2 and O2 varies among maturity stages and cultivars; but a satisfactory CA is 3% O2 and 2% CO2. Storage in 3% O2 and 97% N2 extended postharvest life of mature-green tomatoes for 6 weeks at 13°C without development of off-flavours.
Storage disorders
Alternaria rot, Anthracnose, Bacterial soft rot, Bacterial speck, Blight, Canker, Chilling injury, Grey mould rot, Internal browning, Leaf spot, Splitting, Water rot, Watery soft rot.