The Early Beginnings of Controlled Atmosphere Storage
Today, the marketing of apples and pears in virtually all fruit-growing regions of the world depends upon controlled atmosphere (CA) storage technology. CA provides a means of regulating supplies of apples, pears and other produce. These fruits are harvested over a relatively short period, yet through the use of CA storage, they can now be made available to the public for most of the year.
Dr. Richard Sharples, head of the Division of Fruit Storage of the Institute of Horticultural Research at East Malling, has recently published a paper describing the development of CA storage in "Classical Papers in Horticultural Science." (1)
As early as the 19th century, research workers reported on the beneficial effects of high concentrations of carbon dioxide and low oxygen in the preservation of fruits. In 1918, the first detailed systematic research on the so-called "gas" storage of fruit was initiated by Franklin Kidd and Cyril West in England.
Their work culminated in two classical papers on the storage of apples, based on research carried out between 1918 and 1927 at the Low Temperature Laboratory for Research in Biochemistry and Biophysics at Cambridge (England). It is from Kidd and West that Drs. Bob Smock (Cornell), Archie Van Doren and Max Patterson (Washington State University), Ken Olsen and others obtained basic information about fruit behavior in CA storage. These scientists were then faced with the challenge of adapting these techniques to local varieties and growing conditions. If you wish to learn more about the development of CA storage, consult Volume 1, No. 1, of the Postharvest Pomology Newsletter.(1) Jules Janick, editor, Prentice Hall, 1989
Franklin Kidd & Cyril West
As a young scientist in the early 1900s, Franklin Kidd studied the effects of low oxygen and high carbon dioxide in seed dormancy under the supervision of Professor F. F. Blackman in Cambridge. During this time, Cyril West began the same type of work in London under V. H. Blackman, the brother of F. F. Blackman. The Blackman brothers decided that it would be useful to ask Kidd and West to work together at the Imperial College in London.
In 1917, concern over food shortages during World War I led the government to establish the Food Investigation Organization (FIO). The FIO immediately brought together workers from different disciplines. One of the major problems, pointed out to the government by a leading fruit grower, was the extensive spoilage of apples in storage. Franklin Kidd was recruited to study ways of improving fruit storage; he quickly asked Cyril West to join him.
Applying information obtained while studying seed germination, Kidd and West demonstrated that fruit ripening could be retarded by increasing carbon dioxide and lowering oxygen in the storage atmosphere. By 1926 they had constructed three special cabinets, each of which had ten gas-tight compartments. Using the relatively crude measuring systems of the day, they were able to keep careful control of the experimental conditions.
The two men began their work using refrigerated rooms in the medical school in Cambridge. Later they obtained cold storage space for their experiments at the London docks. They began some semi-commercial trials on apples during the 1920-21 season at a farm near their Cambridge laboratory. At first, their objective was to substitute gas storage for refrigeration, since refrigerated storage space was not generally available on farms.
They discovered that they could successfully hold freshly harvested apples in gas storage without refrigeration during cold weather. However, they could not demonstrate any advantage of gas storage, without refrigeration, during warm weather. They found that large quantities of fruit stored together generated heat (due to respiration). These findings convinced Kidd and West that refrigeration was needed as a component of gas storage.
The research team kept careful records of the amount and type of rots and disorders which appeared on fruit held under different storage conditions. Kidd and West soon recognized that these disorders were associated with specific storage conditions and that it would be necessary to set very precise Emits of temperature, oxygen and carbon dioxide for each variety.
They discovered that fruit volatiles accumulated in gas storage which could be harmful to the fruit, so they developed oil wraps to protect fruit from storage scald.
Once the work of Kidd and West was published, growers began to build refrigerated gas storages. The first gas storage was erected near Canterbury in 1929. By 1932 five large commercial gas storages were operating with a capacity* of 1500 tons. In all of these cases, the atmosphere was held at 8-10% carbon dioxide by restricting ventilation.
In 1927 Kidd toured Australia, Canada, the United States, South Africa and New Zealand, discussing gas storage. Two years later the Ditton Laboratory was constructed at a site adjacent to the East Malling Research Station in Kent. This laboratory was created to work on problems encountered in the transport of fruit from the southern hemisphere and other aspects of postharvest research. West was appointed Superintendent and remained so for 18 years.
By 1933 scientists from throughout the world began to study at the Ditton Laboratory. They returned home to adapt the ideas and techniques developed there. Successful application of this technology has benefited us all. One of the reasons for their success was that Kidd and West were willing to conduct trials on semicommercial storages along with their laboratory experiments. In addition, they were excellent scientists and competent communicators.
During the early 1940s, with the war raging in Europe, a group of postharvest scientists gathered in New York decided to change the name from "gas storage" to "controlled atmosphere storage," thus, the name CA was born.
Although Kidd and West collaborated on 46 papers during their lifetimes, they rarely met outside the laboratory. Kidd was an avid walker a naturalist, gardener and beekeeper. He also wrote poetry and painted. West, who was interested in systematic botany, was honored for his contribution to that field.
It is a testimony to these scientists that their results were directly and immediately applicable. The recommendations which they developed for storage of Bramley apples in the 1930s are still in use in England today.
Dr. Eugene Kupferman, Postharvest Specialist
WSU Tree Fruit Research and Extension Center
1100 N. Western Ave., Wenatchee, WA 98801
Post Harvest Pomology Newsletter, 7(2): 3-4