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Radish, Raphanus sativus / Cruciferae (Brassicaceae)
Postharvest Atmosphere Management
Fresh radishes have a good preservation, specially if the green parts are removed, since they tend to accelerate the drying of the root. It is recommended to keep them in the fridge, inside a perforated plastic bag. In this way they are kept fresh for one week. It is recommended not to wash them until consumption, in order to increase their self life.

They are stored at 2ºC to 5ºC and air relative moisture between 90 and 96%.

Pre-cooling is recommended for radishes with and without leaves, by means of hydro-cooling or humid air.

The storage methods for radishes are not common techniques because they are found all the year round and they are also highly perishable when the leaves are removed. At present, the cooling and packaging systems make possible the relatively extensive transport of this type of defoliated produce. The optimal storage conditions oscillate around 0ºC and high relative moisture (90-95%) and the period of storage depends on the type of radish. The late cultivars are the most suitable for preservation during 4-6 months, whereas the early ones only last for two weeks. Nevertheless, this species is usually marketed immediately.

The controlled atmosphere is not an outstanding system for this species. However, there are evidences of positive effects shown when, due to the distance between the markets, the consumption does not take place before two weeks and the temperatures of transport are not low enough. The growth of leaves and roots is diminished when radishes are stored at 5 or 10ºC and the levels of oxygen are between1 and 2%. These benefits are maintained when they are transferred into a normal atmosphere (air) for 3 days.
Distribution
High relative moisture (90-95%) and low temperatures (0ºC) must be adapted for conservation, conferring a fresh appearance to the produce.
Postharvest Problems
The type of presentation is a condition of behaviour during post-harvesting. The leaves become a highly perishable part of the vegetable and susceptible to show symptoms of dehydration and yellowness.

The yellowing of the leaves, the loss of chlorophyll, is a phenomenon accelerated with the presence of ethylene in the atmosphere. Low temperatures and high relative moisture increase this alteration. In Spain there are no products registered to be applied when this phenomenon arises.

The most frequent alterations affecting this root are the growth of leaves and roots, the softening and loss of weight, presence of bruises, sponge appearance, physiological alterations such as frost injuries and cavities, and parasitic diseases.

The growth of leaves and roots is a phenomenon that affects the appearance of the produce in the market. These are inhibited by means of low temperatures (0ºC).

The softening and loss of weight are mainly due to the loss of water and they are controlled with high relative moisture along with low temperatures.

Bruises are due to impacts during the mechanical harvesting; when the produce is hand harvested the incidence of this damage is usually smaller. Fast pre-cooling reduces the amount of damages.

The sponge appearance is an alteration that may arise during the harvesting and continues its development during post-harvesting.

The most frequent physiological alterations are chilling injuries and cavities. Freezing takes place at temperatures of -0,7ºC. In severe cases the roots soften, loose humidity and wrinkle.

The cavities are symptoms of senescence and may occur before or after the harvesting, increasing its frequency during storage. Its incidence is reduced with low temperatures.

During the post-harvesting, as it happens in the field, radishes may be affected by parasitic diseases. The two most common diseases are Powdery mildew (caused by the fungus Peronospora) and the Bacterial black spot (caused by Xanthomonas vesicatoria).
Interempresas Media, S.L. / 2019 [ Legal notice | Política de Protección de Datos | Política de cookies | Publicidad]