Bred to be sweeter, today's cherries, bananas and apples taste different than they used to but not necessarily better. Among fruit farmers, the word "quality" is now routinely used as a standard for "high in sugar", though firmness, color and size are also considerations. In a recent study about ways to enhance the sweetness of fruit using "molecular (分子的) approaches", a group of plant scientists wrote that, in general, the sugar content of many fruits are now higher than before owing to continuous selection and breeding. Modern apple varieties, the scientists stressed, were on average sweeter than older ones.
The sweetness of fruit depends not just on how it is bred but also on growing conditions, yield and harvest. The lead researcher, Sugiura, said, "If you could taste an apple harvested 30 years ago, you would feel the difference." He believed that modern apples are picked so early that even if they are bred for sweetness, they often don't develop their full character. The fragrance never develops in fruit that is harvested too early.
Jim Cooper, an apple farmer in England, is regretful to admit the fact that many people will never taste the "strawberry hint" in a really ripe Pearmain, a type of heritage apple. In a way, the rise of consistently sweeter fruit in our lifetimes has been a victory of plant breeding. After all, it's a rare person who would seek out bitter grapes if they could have sweet ones instead.
But the sweetness of modern fruit is not without its problems, especially for people with diabetes (糖尿病), who have to reduce their intake of higher-sugar fruits. Fruit that is bred sweeter also tends to be lower in the chemicals that make it healthy. Considering health, maybe the real problem with modern fruit is that it has become yet another sweet thing in a world with sugar. Even grapefruits, which used to be quite bitter, are sometimes now as sweet as oranges. If you've never tasted a sour cherry, how can you fully appreciate a sweet one?
