Ethylene: The responsible for the ripening of fruits and vegetables
Ethylene is a plant hormone, and it is the only hormone that is a gas.
Ethylene is a gaseous organic compound, consisting of two carbon atoms and four hydrogen atoms and is the first term of the alkene series. It is a colorless gas with a pleasant odor. Ethylene is not only of industrial importance, but it is also a hormone synthesized by plants and its action affects the development of plants, from seed germination to senescence and death of the seeds.
Ethylene is considered “the aging hormone of plants”. This gas is responsible for the ripening of fruits and vegetables, causing them to change color, obtain a softer texture and develop their characteristic flavor and aroma.
Fruits are classified into climacteric and non-climacteric according to their respiratory pattern and ethylene production during ripening:
Climacteric fruits significantly increase respiratory rate and ethylene production during ripening. The associated changes (color, flavor, aroma, texture) are rapid and intense. Among others: Apple, Mango, Avocado, Banana, Plum, Custard Apple, Fig, Melon, Peach, Pear, Tomato, Watermelon, Onions.
In non-climacteric fruits, ripening processes are continuous and gradual, maintaining low levels of respiration and ethylene production at all times. Among others: Cherry, Pumpkin, Grape, Grapefruit, Grapefruit, Pineapple, Lemon, Orange, Tangerine, Strawberry.
In addition to this, there are fruits and vegetables that are very sensitive to ethylene. For example, broccoli, lettuce, asparagus, potatoes or carrots. See Table 2.
When a ripe fruit releases ethylene it accelerates the ripening of the fruits around it, causing them to decompose much faster than normal: bitter taste in carrots, increased roughness of asparagus leaves, reddish spots on lettuce, loss of color in broccoli or softening of ripe green tomatoes.
Maintaining good post-harvest food quality and ensuring that it reaches the consumer in perfect condition is very important for any fruit grower or distributor. As natural post-harvest ethylene production is inevitable, in addition to other artificial sources of this gas such as internal combustion engines, it is essential to take the necessary measures to ensure that ethylene does not affect the quality of fruits and vegetables transported to supermarkets.
Other sources of ethylene in the environment
In addition to the ethylene produced by the fruits themselves, fruits are exposed to different sources of exogenous ethylene during storage and transport:
Sources of Pathogens: Many species of bacteria and fungi produce ethylene.
Human sources: Any human activity involving combustion will produce ethylene.
Cross-contamination: Both in fruits in the same container and between containers and chambers.