Israel: Benefits of modified packing and storage for cucumbers

Cucumbers belong to the gourd family (Cucurbitaceae) and although in culinary terms they are considered a vegetable, botanically speaking, they are a seed bearing fruit. Although cucumbers have very few calories (approx. 15 in 100g) they certainly don’t lack important nutrients providing a variety of health supportive phytonutrients including flavonoids, triterpenes and lignans (1). They are also an excellent source of molybdenum, vitamin K, vitamin C, potassium, magnesium, manganese, and vitamin B5.

Commercial production of cucumbers is usually divided into two types. "Slicing cucumbers" are produced for fresh consumption whereas "Pickling cucumbers" are produced for eventual processing into pickles. Slicing cucumbers are usually larger and have thicker skins, while pickling cucumbers are usually smaller and have thinner skins. Depending on cultivar and temperature, the time from flowering to harvest may be 55 to 60 days. Generally, fruit is harvested at a slightly immature stage, near full size but before seeds fully enlarge and harden. At proper harvest maturity, a jellylike material has begun to form in the seed cavity.

Harvesting should be done by cutting free of the vine rather than by tearing. Cucumbers are highly impact and pressure-sensitive and should be handled gently to avoid mechanical damage which will result in spoilage. Cucumbers should be harvested into light colored crates that should be well ventilated and kept out of the sun to avoid temperature increase. As for other produce items, crates should be regularly washed to prevent cross contamination.

Cucumbers should be cooled promptly after arrival at the packing house to remove field heat and extend storability. The optimum storage conditions for cucumbers are 10-12°C and 90-95% relative humidity.

Within this very narrow range of temperatures, cucumbers can be kept for 10-14 days.

Storage of cucumbers at below
100C will result in chilling injury which manifests itself as water soaked areas, surface pitting and increased susceptibility to decay and yellowing. The symptoms of chilling injury are more prominent once the fruits are transferred to higher temperatures.

Storage of cucumbers at temperatures above 10-12°C results in rapid senescence, decay, and in same cultivars, development of warts on the surface which is a physiological disorder.

Since cucumbers are highly sensitive to exogenous ethylene, they should not be stored with ethylene producing commodities and exposure to low levels will result in accelerated yellowing and decay.

Modified atmosphere packaging and storage
Cucumbers benefit from modified atmosphere conditions which slow down ageing, inhibit decay and chilling injury. The high relative humidity within the packaging environment also reduces weight loss. Nevertheless, storage in Polyethylene based modified atmosphere packaging poses a risk since the film has a low moisture vapor transmission rate, excess moisture in the packaging is likely to expedite decay either during the storage/transportation period or after removal from the packaging.
When cucumbers are handled correctly and stored in Xtend® MA/MH packaging, characterized by high moisture vapor transmission rates, storability can be extended to up to three weeks. The major benefits of the packaging are:

Reduced dehydration and weight loss, thereby preserving firmness
Reduced decay
Inhibition of chilling injury
Slowed senescence (ageing)

These benefits allows for expansion of markets and more uniform and higher quality at any one time.

Typical storability in Xtend® packaging is given in the table below:

For more information:
Ms. Andy Swersky
StePac L.A. Ltd
Tel: +972 (0)4-987-2131
info@stepac.com
www.stepac.com