Can I use more than 150 ppm of ethylene to speed up the ripening?
It serves no purpose because the additional ethylene has no effect. Any ethylene exposure over 150 ppm does not hurt the fruit* but the extra ethylene provides no benefit. Once the proper ethylene level is attained, the only thing that will speed up the ripening process is a higher temperature. Sometime fruit that has been ripened at too high of a pulp temperature is referred to as “overgassed.” Often the cause of poor quality associated with this misnomer is not excessive ethylene but extreme pulp temperature at some period in the postharvest life of the fruit, or poor fruit quality, such as old, stale fruit. *Note: Citrus is an exception; it cannot be exposed to more than 10 ppm and the precise ppm level depends upon variety).
