English apple storage has changed dramatically over the last 50 years, with market forces dictating the need for investment in new technology.

By the mid 1990s Cox growers were under serious threat, and with Gala and Braeburn pouring in from France and other EU countries during the English season, the demise of Cox accelerated. Many growers either sold up or, where possible, grubbed up and started planting Gala and Braeburn. These new varieties are now producing high volumes of quality fruit and, with yields per acre far in excess of Cox, can compete with prices of imported fruit. They also have the capability to be stored beyond the end of April, thus extending the opportunity for consumers to enjoy English apples.

But the store investment made in the 1970s and 80s is now inadequate for the increased volume and storage periods. Systems for controlling storage conditions like ultra low oxygen, carbon and ethylene scrubbing depend on well-constructed airtight chambers.

Research conducted early in 2012 concluded that there is an estimated shortage of economically viable fruit storage facilities of 45 per cent in the UK. Working with AC Goatham & Son and Landseer, ICA was part of a nationwide project evaluating storage potential, both in the short term but also with an eye on the increasing volume of homegrown fruit.

With an industry-stated aim of a 50 per cent market share and also the increasing use of on-farm facilities for southern hemisphere product assessment, serious improvements have had to be made. At current planting rates, by 2016 the UK should be growing 800,000 bins of fruit (273,000 tonnes), but as of mid-2012 the figure was 529,500 bin capacity of usable storage that will be economic to run in 2016, leaving a shortfall of 272,500 bins.

Two such companies working hard to bridge this facilities gap are ICA and its sister company STS. With over 70 years of experience in controlled atmosphere and cold storage these two have led the sector for many years.

Legislative changes mean that the whole storage sector is extremely conscious of the environmental impact of their materials, construction methods and longevity of their units and these two businesses, while providing a ground-up project management service for new build, also specialise in the utilisation of existing facilities and breathing new life into them through refurbishment of store spaces and the replacement/upgrading of technology.

New builds in the last 12 months alone have delivered 25,000 bin capacity of new top-fruit storage, with 3,500 bin capacity of refurbished storage to the sector, spread across 10 sites. One of the major contributing factors in store performance improvement in the last 20 years has been the move away from polyurethane and polystyrene panels (not recyclable, caused fires, variable density, do not break down for recycling) to insulated panel systems, such as those made by Kingspan.

Offering greater tensile strength, mould and fungus resistance and greater insulating properties, they also come with an end-of-life guarantee which means they can pass through conventional shredder plants when the store finishes service. Modern construction materials coupled with advanced CA plant now delivers very low energy usage, in excess of 45 per cent more efficient than in the 80s, delivered through the control of CO2 and 02 levels as well as temperature management.

CASE STUDY – Hycool installation for AC Goatham at Flanders farm

The 12 CA stores at Flanders farm (the new AC Goatham HQ complex) use the energy-saving secondary refrigeration system based on Hycool 20, a fluid that is efficient, non toxic, biodegradable and food safe.

AC Goatham has experienced the secondary system – which will in time replace the older DX refrigeration systems which have a much more harmful effect on the environment at other developments across their business. “ We have seen electricity bills fall by between 35 and 40 per cent,” said senior partner Clive Goatham. “This is more than ICA originally claimed for the system and is very impressive” . Energy economy of this system is a big appeal but the real advantage is the fast pulldown rate removing field heat so fruit can be stored in peak condition.

ICA’s sister company, STS Refrigeration, provides the expertise in the cold storage technology, and it too has had a busy year. As everybody is probably aware, refrigeration plant makes one of the highest on-farm demands on the National Grid and on grower’s pockets. Energy prices are constantly rising, and companies like STS have to look at ways of reducing the power requirements of expensive-to-run storage units, not only with new-build projects, but with existing equipment too. Many sites have a limited amount of power available to them, impinging on the potential to expand storage capacity as the national crop rises in volume.

CASE STUDY – Newmafruit

With company production at 32,000 bins and rising, the pressures of maintaining efficient storage facilities is at the forefront of development at the Chartham site of Newmafruit Farms.

With significant savings of between 30-40 per cent on farm made in the last few years through cost effectiveness, time management and efficiencies, Mike Barnett and his team turned their attention to potential savings in the CA store facilities. The first retrofit project gave an energy saving of 35 per cent on a 3,000t storage unit (with annual electricity bills for this unit running at £60,000, £21,000 off the bill is quite a saving); the second project, for the high-traffic racked storage area, required an initial investment of £11,480, and the energy bill for this area was reduced by £10,976 in the first 12 months, meaning payback was in 13 months. With the retrofit of the Danfosss and Hycool systems, structurally sound stores increase in productivity and contribution to the business.

As new technologies emerge the applications can have substantial commercial benefits for the consumer – just looking at ripening and fruit conditioning rooms alone, the change in the quality of ready-to-eat stonefruit and pears in the last five years has meant better guarantees of shelf life and product performance in the home. Air flow is the main variant in comparison to traditional store designs; the environment is managed so the whole pallet of product has an even flow of air through it at all times, the stores also have control system for managing ethylene levels, temperature and humidity.

All rooms have flexibility on pallet loading, so unlike traditional produce stores, capacity does not have to be reached to ensure perfect performance. The CA plant takes into account variable air flow so units can be zoned to manage smaller numbers of pallets.

New advances in fruit conditioning facilities include UV technology, which is being trialed at DPS site hosted by Cross and Wells. The colonisation of airborne micro-organisms and the inherent proneness of fresh produce to spoiling can pose significant problems. Maintaining exceptional air quality throughout the production process not only enhances shelf life and preserves product quality, it could also give a competitive advantage. An AirStream disinfection module has been added to one of the units in the new DPS storage units, the system re-circulates the air within the ripening room 20 times per hour, and employs 12 high-power UV-C emitters which minimise the risk of product contamination by moulds, fungi, bacteria or other pathogens.

So what does 2013 bring for fruit storage? Technological advances mean that we will see a further lowering of oxygen levels, thus reducing respiration rates, and therefore senescence in the fruit.

Dynamic CA is already being trialed across the world, especially in Italy and Holland. The theory behind dynamic CA is that each store is treated differently. Described as ‘reducing the oxygen until the pips squeak’ by David Bishop of ICA, it measures the fruit to check for stress as the oxygen is removed. These levels are then raised slightly, maintaining the conditions suitable for that individual store of fruit as opposed to the generic programme for the variety developed by research stations like EMR.

The stress point of the fruit is measured is varying ways, depending on whose system is employed; by fluorescence on the skin surface, or the alcohol levels in the fruit or measuring the respiration rate. There appears to be a consensus in the UK, at present, that the jury is out as to whether this is something for the future or not.