Does One Bad Apple Spoil All the Apples?

Bad apples produce ethylene, a ripening accelerator.

Plants produce ethylene, a gaseous hormone that signals fruits to ripen and eventually spoil. Numerous factors influence ethylene production, including tissue damage. The ethylene gas produced by injured or diseased fruit is capable of accelerating the ripening and spoilage of other fruits nearby.

Purpose of Ripening

Plants propagate through seed dispersal. Enzymatic reactions initiated by ethylene gas ripen green, sour, hard and odorless fruits to make them more appealing to the senses. Ripening increases the probability that an animal will eat the fruit and through defecation, disperse the seeds at another location.

Controlling Ripening

Jenn Nemec, associate editor for "GRIT" magazine, claims cool temperatures inhibit the ripening process. Producers store unripe fruit in refrigerated, ethylene-clearing warehouses to retard ripening until the fruit goes to market. Consumers can accelerate ripening by placing an ethylene-producing fruit, such as a ripe banana, in a sealed paper bag with the unripe fruit.

One Bad Apple

According to Ross E Koning, a botany professor at Eastern Connecticut State University, people once packed apples in barrels for winter storage in root cellars. The cool cellar temperatures kept the apples from ripening as long as there were no damaged apples in the barrel. If a damaged apple was mistakenly included, the ethylene gas it produced accelerated the ripening and spoilage of all the other apples in the barrel.

References

• "GRIT": What Makes Fruit Ripen?
• Plant Physiology Information Website: Fruit Ripening
• "Scientific American": The Origin of Fruit Ripening

Resources

• Salk Institute: Why Fruits Ripen and Flowers Die