Studies of the Physiologically-Active Volatile Organic Compounds Produced By Fruits: I. The Concentrations of Volatile Organic Compounds Occurring in Gas Stores Containing Apples

When apples begin to ripen after gathering, volatile products are given off. Some of these account for the smell of the fruit; another is the gas ethylene. These volatile products affect the rate at which the apples ripen, and are probably also responsible for such diseases of storage as superficial scald and spotting of the lenticels. The volatile products tend to collect in the atmosphere of the store and hence also m the fruit, particularly with tight packing or when the ventilation is restricted, as in gas storage. It is necessary to use oiled paper wraps in gas-storage, to prevent scald, but this is a laborious and somewhat costly procedure. It is hoped to reduce the amount of the volatiles in the atmosphere of the store, and thus to control scald, by employing a filter containing some material to absorb the volatiles. The filter would have the atmosphere of the store circulated through it, and could be fitted either inside or outside the store.This paper describes an investigation, the first of its kind, of the amounts of the volatile products occurring in the atmosphere of gas-stores under present methods of operation. The main feature is the suprisingly high concentration of ethylene found in the stores. The amount present would, in ordinary air, be expected to cause stimulation and acceleration of ripening.This raises the question whether, if ethylene could be removed, further benefits in delay of ripening could be obtained.