By Engela Duvenage
A veritable trip down memory lane – that’s what Dr Elke Crouch recently went on while preparing for her new responsibilities as Post-Harvest Physiology Research Chair in Deciduous Fruit at Stellenbosch University.
She set off for the Elgin/Grabouw area in the company of Richard Hurndall, former Postharvest Manager of Hortgro Science who initiated the revival of CA research and facility expansion in recent times. First up they headed for Fruitways Molteno storage facilities near Elgin station that was built by Molteno Brothers in 1934. The initial 7-room complex was the first commercial CA facility built outside of England, where research on the technology started in 1918.
Crouch sheds light on its significance in fruit storage history and refers to a manual that she knows well namely the 2017 South African controlled atmosphere storage operator’s manual. According to the manual, an engineer from Cambridge, Mr E Griffiths, supervised the construction work. Each room held ±6 000 lugs of fruit. When it was later enlarged to 21 rooms to hold 127 000 lugs of apples, it was one of the largest CA installations in the world.
“Some of the materials used might have been salvaged from a ship or something because some windows look like portholes,” Crouch guessed after the visit. “The best part is that this building is still being used.”
The Manual also explains that it wasn’t all plain sailing working in the facility in those early days. Mr Fausto Alberti ran the CA stores for Molteno Bros during the 1940s and 50s, is quoted as saying that he used to get extremely breathless when he went inside to change the lime, examine fruit and inspect ammonia coils. The caustic soda in the lime scrubber also damaged overalls and other clothing.
‘Ohenimuri’ apples were kept in fairly satisfactory condition until August, whilst ‘Winter Pearmains’ could be taken through to September. According to the Manual, up to 30% of fruit stored were lost due to rot. It did, however, make it possible to spread fruit sales as the local market only came into being during the 1940s.
Whereas interest in CA technology picked up elsewhere in the 1950s and 1960s, it waned in South Africa, in part thanks to significant advancements in Regular Atmosphere storage. Sterling work was done by the cold storage section of the former FFTRI (now ARC Infruitec-Nietvoorbij) led by Mr Lossie Ginsburg. It allowed ‘Golden Delicious’ and red varieties to be kept until September/October, and ‘Granny Smith’ until November.
Local interest in CA only again piqued in the late 1970s when producers realised there was a real market for apples and pears in December and January, despite competition from early stone fruit. Attempts in 1976 and 1977 to repurpose RA stores by constructing tents inside to control atmospheres and temperatures proved worthless. It did not improve fruit quality.
In 1978 a delegation of growers, cold store operators, and scientists visited CA storage facilities in Europe, Israel, UK, and the USA. Upon their return they set the proverbial ball rolling. Also in 1978, Elgin Fruit Packers Cooperative (ELFCO, now part of Two-a-Day) sent director D. H. Cunningham and engineer Charles Brislin to study CA facilities in Washington State in America. Upon their return wood was used to build the first jacketed CA store in South Africa, ready for the 1979 season. “It’s built just a stone’s throw away from the original Molteno store, and also deserves its place in South Africa’s CA history, because it was the start of new things,” Crouch believes.
On their visit to the facility, Crouch and Hurndall were escorted by Darrin Meiring, refrigeration manager at Two-a-Day. His grandfather, Harrold ‘Tinkie’ Meiring was a local carpenter who helped with its construction in 1978.
Books filled with newspaper clippings tell how excited the industry was about its construction. “Controlled-atmosphere stores stretch marketing period for apples from 6 to 12 months” one headline exclaimed, while The Argus proclaimed: “Elgin ensures quality apples”. Dr Adriaan du Toit, general manager of ELFCO, told Die Burger at the time that building the new storage facility would cost R850 000 – a huge investment at the time.
In 2007 Meiring followed in Grandpa Tinkie’s footsteps by overseeing the renovation of the facility. The wood was replaced by polystyrene, and the room sizes decreasing in line with industry requirements.
“The newer materials keep heat out and temperatures cool inside. It’s easier to seal than with wood,” Meiring says.
In line with how the industry started embracing CA technology in the late 1970s, an information-sharing group was set up in 1978. It developed into the CA Storage and Postharvest Group in 1981. The first local research was done in 1983 after the CA Storage and Operators’ Group persuaded the then Deciduous Fruit Board to experiment with the export of fruit from CA storage during June, July, and August. It led to the export of 89 000 cartons of Granny Smith and 7 000 cartons of Top Red apples.
The ARC continues its studies on the topic today. “It’s exciting to realise that from the start research was done as a team effort, and with industry support. I like the fact that everyone doing CA studies today still works together,” says Crouch, who is thankful for the cooperation that her SU Research Chair receives from Hortgro, the ARC, and ExperiCo to provide storage guidelines for different cultivars to industry.
CA in numbers:
- CA storage capacity in South Africa increased between 1978 and 1983 by 733%.
- An average growth rate of more than 35% per annum was maintained from 1984 to 1992.
- Long-term controlled atmosphere (CA) storage capacity for apples and pears in SA is estimated at 1,5 million bins.
- In some countries, more than 50% of apple and pear crops are stored in CA facilities.
CA’s baby steps
- 1821- Frenchman Jacques Bèrard shows one can control fruit respiration by altering the composition of the atmosphere surrounding it.
- 1897 – Italian Michelangelo Borelli suggests that gas mixtures be used to store fresh fruits.
- 1899 – Spaniard Manuel Belmonte receives a patent to store grapes in carbon dioxide.
- 1918 – At Cambridge University in England Franklyn Kidd and Cyril West start experiments to store apples without refrigeration in artificially generated gas mixtures.
- 1925 – They publish their first papers. The duo proves that apples can be stored successfully in gas-tight containers when O2 levels deplete through natural respiration and CO2 content increases.
- 1929 – The world’s first commercial CA store is a 30 tonne one built near Canterbury in England.
- 1930s – Scrubbers consisting of chemicals are developed to remove CO2 from the atmosphere. This included soda ash, lime, and a suspension of lime in water, ethanolamine, bicarbonate of soda, and activated charcoal.
- 1934 – Molteno Brothers in Grabouw builds the first CA store outside the UK.
- 1938 – The Netherlands gets its first 100-tonne chamber.
- 1942 – America gets its first CA store in the Hudson Valley to store ‘McIntosh’ apples.
Source: Van Bodegom, P (2017). Revised edition of the South African controlled atmosphere storage operator’s manual
Ins and outs of the first Molteno Brothers CA store:
- The initial 7-room building consisted of a steel shell, supported by lattice girders.
- It was built by Consani Engineering.
- Soap foam cement blocks served as insulation inside.
- Refrigeration was supplied by ceiling-mounted ammonia-cooled coils.
- All cooling of fruit was done by air convection and conduction. No fans were used to circulate air.
- Lime was put into the room to control some of the CO2, but the CO2 was mainly controlled by a portable scrubber consisting of a 500 gallon discarded fuel tank (probably underground petrol) on wheels containing caustic soda.
- CO2-laden air from each room was sucked through the tank. It effectively maintained CO2 concentrations at around 5%.