What gas is known to accelerate the ripening of fruits during storage?

Ethylene gas is a plant hormone that plays a crucial role in the ripening process of fruits. It is naturally produced by many fruits and vegetables, and its presence signifies the beginning of the ripening process. When fruits are exposed to ethylene, it triggers a series of biochemical reactions that lead to changes in texture, color, and flavor, thus making the fruit more palatable and appealing.

During storage, ethylene can accumulate, especially when fruits are packed closely together, potentially leading to accelerated ripening. This property is commonly utilized in the agricultural and food industries to manage the timing of fruit ripening, especially during shipping and storage. For instance, fruits like bananas and tomatoes are often exposed to controlled amounts of ethylene gas to ensure they ripen uniformly and are ready for sale.

On the other hand, the other gases listed do not function in the same way. Carbon dioxide is often associated with spoilage and can inhibit the ripening process, ozone is used for its antibacterial properties and doesn't promote ripening, and acetylene has some similar effects to ethylene but is less commonly used in practical applications for fruit ripening. Thus, ethylene gas stands out as the definitive agent that accelerates the ripening process in fruits during storage.