CoolBerry 2: Innovations for in-field cooling of soft fruit

"Removal of field heat from perishable produce is critical for quality and storability. This project will develop and test a mobile field based Cooling-rig, initially for soft fruit, that will enable growers to rapidly remove the field-heat from produce immediately after harvest to below 5°C.

Currently, in-field cooling options are not used in the UK. Existing technology is available in the USA, but utilises direct expansion cooling, has low energy efficiency and lacks precision, therefore increasing moisture loss.

By taking the cooling technology to a higher level of sophistication, the development of the Cooling Cell will have a major impact on retaining optimum fruit quality, increasing shelf-life of fruit and reducing losses in the supply chain incurred due to weight loss, bruising and disease development. While the focus will initially be on soft fruit, the technology will then be expanded to include stone fruit and fine vegetables.

The project will start by building test Cooling-Cells to optimise the process in terms of rate of cooling, and control of humidity to minimise moisture loss, which can be a major problem during cooling. Tests will also be carried out to determine whether moisture loss can be reduced further by using pressures elevated above atmospheric during cooling. The design and composition of packaging will also be optimised to improve the rate and efficiency of cooling, thereby reducing energy usage.

The prototype cooling rig will be developed with growers to ensure that it is appropriate for the logistics of complex field harvesting logistics. It is envisaged that the final Cooling-rig will accommodate several pallets of produce (up to six in total) in segmented chambers. Cooling will be delivered individually to the three pairs of chambers allowing pallets to be cooled immediately after harvest and removed via a temperature cooled van to the pack-house to minimise temperature fluctuations in the supply chain."