www.interempresas.net
  Fruits Vegetables
es en ca
 
Red Cabbage, Brassica oleracea var. rubra / Cruciferae (Brassicaceae)
Postharvest Atmosphere Management
Red Cabbage
As compared with the rest of vegetables, fresh red cabbages are preserved in good conditions for a long time. The vegetables’ drawer of the fridge is the best place to keep them at home in perforated plastic bags, lasting up to 2 or 3 weeks.

Pre-cooling is an optional technique and it is generally used when the temperature during the harvesting is high, being the most suitable method that of humid air.

In Spain, the storage of this product is not usual since there is fresh merchandise all the year round. The optimal conditions for storage are temperatures around 0ºC and 95% of high relative moisture. Curled cabbages tolerate freezing but it must be avoided.

The use of modified atmospheres with concentrations between 1 and 5% and carbon dioxide between 2 and 6% affects the delay of senescence. Modified atmospheres are used at commercial level in areas of harsh winters where the produce is stored for long periods of time.
Distribution
Temperature during distribution must be around 5 and 10ºC with average moisture and good ventilation. A good presentation is achieved by removing the yellowish leaves.
Postharvest Problems
Headed cabbages, among which the red cabbage is included, are the vegetables with greater post-harvest life. During storage they undergo a series of changes among which stand out the reduction of weight, yellowness of the leaves, the leaves’ abscission, hardening, the heart’s lengthening, growth of the axillary and apical buds, growth of the roots, parasitic diseases and physiological alterations.

Cabbages undergo the greater loss of weight during the first week of storage. The longer the time of storage and the lower the environmental relative moisture, the greater the total reduction of weight.

The loss of chlorophyll gives rise to the yellowing of the leaves, which is a symptom of senescence. This alteration is accelerated with high relative moisture and the presence of ethylene.

The presence of ethylene accelerates the loss of chlorophyll and brings about the abscission of the leaves. After two months with concentration of 1ppm in the environment the abscission of the leaves is greater.

An indicator of the end of the storage for red cabbages is the lengthening of the heart, that may take place towards the middle of the period of storage.

The development of the apical bud represents a loss of self-life for this vegetable. The behaviour of the axillary yolks also varies according to the cultivar’s capacity for storage and the effect that the environmental conditions exert on this characteristic.

Red cabbages may be affected by parasitic diseases like Botrytis cinerea, Alternaria, Mycosphaerella brassicicola, Sclerotinia sclerotiorum, Rhizoctonia solani, Phytophtora porri, Fusarium, Pseudomonas sp. and Erwinia sp. Botrytis cinerea gives rise to a grey rot, one of the main pathogens in cabbage post-harvest. Several species of Alternaria affect damaged cabbages, bringing about similar symptoms. The affected tissues show dark brown spots with flexible texture. Mycosphaerella brassicicola causes annular spots like dark greyish-brown or black injuries, and the tissue dries. Sclerotinia sclerotiorum is another important post-harvest pathogen that develops a soft and watery rot originated in the field infections. Some other fungi that may cause problems are Rhizoctonia solani, Phytophora porri, and Fusarium roseum. The bacterium Xanthomonas campestris causes a black rot. Erwinia carotovora and Pseudomonas marginalis give rise to a soft rot that in the case of the latter is wet and viscous, with an unpleasant bitter smell.

Among the most outstanding physiological alterations we find "Tip burn" or "Scorch" that causes rotting during storage, "Grey speck", that causes dark pointed spots chiefly in the basal area of the leaf blade, "Vein streaking" is an alteration that occurs in prolonged storage and is formed by black or brown signs along the petiole and central rib that may extend up to the large ribs of the leaves, The symptoms of " Black midrib" are black tissues in the petioles of the head’s leaves, " Necrotic spot" is another disorder of unknown etiology that occurs during storage, giving rise to depressed injuries of more than 1 millimetre of diameter, with a round, oval or irregular round shape, on the midrib, the sides of it or in both sides of the leaf blade.
Interempresas Media, S.L. / 2022 [ Legal notice | Política de Protección de Datos | Política de cookies | Publicidad]