They studied on the data related with the famous Japanese apple species, Fuji, and another species, the Tsugaru.
These species appeared to be both gradually sweeter and softer between 1970 and 2010. These datas were combined with next temperature measurements from these areas by the researchers. Laid per decade, it has become an average of 0.3 degrees Celsius warmer in the areas concerned.
The researchers attribute the changes with these species to the early flowering of apple trees and higher temperatures during the ripening of apples.
Under the influence of sunlight acids in apples transform into sugars. Fruits also lose water during the ripening at a higher temperature, through which processes are accelerated.
Previous research has shown that the flowering of apple trees occurs 2.2 days earlier on average every decade in Germany. That means also Dutch apples may become sweeter and softer.
According to the researchers, any change with the taste apples is not reported by consumers because the difference is not extremely large and the change took place gradually. “But if you taste an apple of thirty years ago and compare it with the taste of todays apples one after the other, then you would definitely notice the difference,” said one of the researchers, Toshihiko Sugiura.
Why the fruit farmers don’t act to harvest the apples are not going to maintain the acidity and texture from the seventies. Possibly the taste preferences of consumers plays an important role in that issue.