Research brings ideal pear storage within reach

Optimization of storage spaces for pears leads to a significantly higher product quality and lower energy use. That's the conclusion following research carried out by Wageningen UR, on behalf of GreenPort Noord-Holland Noord. The project, which involved several chain parties, has yielded innovations and insights with which the fruit sector can strengthen its international competitive edge.

The researchers improved the cold store, working closely together with seven SMEs, on five points. They tested a prototype for an evaporator that can save up to 70% in fan energy, and causes less fluid loss in pears. In addition, the partners came up with an easily applicable method to optimize the air circulation in the cold store. This means the fruit directly behind the door of the cold store will, from now on, be kept under better conditions. A fruit thermostat was developed in the project as well – for sale since 2014 – which gives insight into the air circulation in the room. That enables accurate managing of the cold store climate, and thus the storage quality. The project has also yielded valuable insights for the development of innovative sensors for decay detection. There are now also concrete reference points for optimization of the CO2 scrubber system that filters carbon dioxide out of the air.

Long shelf life pears
"Together, the improvements lead to an estimated 20% lower liquid loss in long-term storage of pears. The energy use can be reduced to 0.15 kWh per tonne per day. That means the energy costs stay about 50% below the national average," says Jan-Willem van der Klugt, project leader of GreenPort Noord-Holland Noord, coordinator of the project. "Growers can store their pears longer and with fewer losses, and are more flexible in the choice of selling market and moment. That means they can negotiate more sharply on sales prices, and improve their international competitive edge."

Multidisciplinary approach
"We have looked at cold stores from different angles: from grower to cold store specialist and sensor developer. That has led to solutions that complement and strengthen each other," says Matthijs Montsma, researcher at the Fresh Food and Chains division of Wageningen UR Food & Biobased Research, and project leader of the study. "This cooperation proves that a multidisciplinary approach works." Apart from Wageningen UR and GreenPort Noord-Holland Noord, the companies Environmental Monitoring Systems (EMS), producer company Fa. J&W Kuin, VDH Control, Koelhuis WFO, Salco BV, Van Amerongen CA Technology and Van Kempen Koudetechniek also participated in the project.

Evaporator, sensors, scrubber system
The project will be followed up in various ways. Food & Biobased Research, together with Dutch refrigeration manufacturer Van Kempen Koudetechniek and Koelhuis WFO from North Holland, is setting up a pilot study to further optimize the prototype of the energy-efficient evaporator. Based on this, the machine is made ready for the market. This year, follow-up studies are also undertaken, focused on sensors for decay detection and redesign of the CO2 scrubber system, for instance through Agrivizier, a subsidy of the EFRO under the banner of GreenPort Noord-Holland Noord.

IPC project Sustainable Storage of Agri Products

The recently completed research project was part of the Innovation Performance Contracts (IPC) project Sustainable Storage of Agri Products (2012-2014), with a total of 11 participating SMEs. Apart from the 'pear cold store of the future', it focused on vacuum drying flower bulbs.