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Cucumbers that stay green longer

The key to the improved fruit shelf life, is mutation of the “stay green gene” in the cucumber plant

Cucumbers which have a shelf life of up to 5 weeks – thanks to mutation induced in the cucumber plant’s DNA – are described in a patent application by Enza Zaden Beheer B.V.

According to documents recently published by the World Intellectual Property Organization (WIPO), even if conventional cucumbers are wrapped in foil to extend their shelf life, they still turn yellow within 1-2 weeks. And while cooling extends the shelf life of some other fresh produce, low temperatures tend to cause chill injury when it comes to cucumbers.

But the Dutch plant breeding company says its invention involves a cucumber plant (Cucumis sativus) producing fruit that, under standard storage conditions, takes 4-5 weeks to turn yellow.

Once ripe and yellow, cucumbers are usually bitter and sour, which is why they are mainly eaten in their unripe green form, it says.

The key to the improved fruit shelf life is mutation of the “stay green gene” in the cucumber plant. The application says the mutation can be introduced by use of mutagenic chemicals such as ethyl methane sulfonate (EMS) or by irradiation of plant material with gamma rays or fast neutrons.

Compared to that in conventional cucumber plants, the expression of the stay green gene in the new plant, or the enzymatic activity of the protein which the gene encodes, is lower.

“In the research that led to the present invention, it was surprisingly found that a reduced expression of the present gene or a reduced enzymatic activity of the present protein provided fruits having an extended shelf life for a time period up to five weeks when stored under standard storing conditions for cucumbers,” the application says.

Source: WIPO, 1. (WO2016012346) STAY GREEN CUCUMBER PLANT:

Image: conventional cucumbers

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Patent sought for orchard climate control system

Inventors Anibal Schurter and John Warmerdam say their orchard climate control system is especially useful for growing kiwifruit and similarly delicate crops.

Kiwifruit can be grown in most moderate temperature marine type climates with adequate summer heat but growing them away from coastal environments can be challenging. Indeed, efforts to grow some of the most popular varieties of kiwifruit in warmer and drier climates have failed, almost universally, says a patent application recently published by the Word Intellectual Property Organization (WIPO).

Thus comes the invention of a humidity and temperature control system for use in the outdoor cultivation of kiwifruit that features an angled sunshade and various fogging type nozzles.

Inventors Anibal Schurter and John Warmerdam say in the application that their climate control system provides for the efficient and controlled introduction of water vapor into an outdoor orchard. “The system is especially useful when employed in the cultivation of kiwifruit and similarly delicate crops, and serves to substantially reduce stresses from heat and low humidity or arid growing conditions.”

“The coupling of shade control and climate control in an outdoor orchard setting is a development of critical importance to the viable cultivation of delicate, humidity and temperature sensitive fruits, such as the kiwifruit,” they say in the application. They also mention its suitability for other fruit susceptible to damage or stress from temperature and humidity variance outside its nominal growing conditions, such as many varieties of apples and pome fruits in general, and most varieties of cherries and stone fruits.


In a preferred embodiment of the orchard climate control system, as employed in a kiwifruit orchard and shown in Figure 1, kiwifruit vines are planted in a row and supported on a trellis with laterals (as seen in figure 2) which train and support the kiwifruit vines. The trellis helps support the shade structure, the water supply pipe and foggers, the application says.

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New way to extend shelf life for ready-to-eat fruit and vegetables

With demand growing for ready-to-eat fruits and vegetables – such as peeled and sliced items – the challenge is to minimise development of microorganisms and changes in the colour, taste and structure of the produce.

One of Turkey’s leading food scientists says he has found a new way to extend the shelf life of ready-to-eat fresh fruits and vegetables.

Vural Gökmen’s method involves immersing the cut fruit and vegetables in a solution containing chitosan and ascorbic acid.

A professor in the food engineering department at Hacettepe University in Ankara, Gökmen says in patent application documents that chitosan is an antibacterial substance that also has antioxidant and anticarcinogenic properties, while the ascorbic acid enables the chitosan to dissolve in the solution and helps prevent browning of the cut fruit or vegetables.

He says that because these substances pose no harm to health, the fruit and vegetables can be eaten without having to be washed.

With demand growing for ready-to-eat fruits and vegetables – such as peeled and sliced items – the challenge is to minimise development of microorganisms and changes in the colour, taste and structure of the produce.

Vural Gökmen, professor in the food engineering department at Hacettepe University, Ankara, Turkey

According to Gökmen, various existing methods for extending shelf life are not effective solutions because they cause the natural colours of the produce to deteriorate or cannot preserve its taste. Also, the produce sometimes needs to be washed before being eaten to remove the antimicrobial substances used to extend its shelf life, which in some cases are toxic.

Gökmen said that in his method, the amount of chitosan within the aqueous solution is preferably 10 gram/litre, while that of ascorbic acid can range from 10–50 gram/litre, according to the particular fruit or vegetable.

Tests on pomegranate seeds using his method with a 1% chitosan and 1% ascorbic acid solution found that 3 weeks later there were no microbiological risks and no change in smell, colour or taste in the pomegranate seeds, Gökmen says in documents published by Patentscope.

Image of pomegrante arils by Ramnath Bhat from PUNE, India [CC BY 2.0 (], via Wikimedia Commons