干果新鲜果的营养差别

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Do dried fruits contain more nutritional value than fresh fruits?

The answer is simple. When you dry fruits, you lose more than just water. You also lose nutrients. For example, when it comes to berries, much of their uniqueness is derived from their phytonutrients. Flavonoids like peonidin, petunidin, malvidin, and many others found in berries are susceptible to damage from heat, light, oxygen, and time-since-harvest. While some drying processes are harsher than others, no drying process can leave the phytonutrient content of these berries significantly unchanged.

Since fruits lose water (and therefore volume) during the drying process, their nutrient, calorie, and sugar content becomes concentrated once they are dried. When you eat a handful of dried fruit, you are consuming more calories than you would if you ate that same amount of fresh fruit.

For example, one-quarter cup of dried apricots contains about 75 calories; for that same amount of calories you could actually enjoy a whole cup of fresh apricots. In contrast to fresh fruits, which we would place in the moderate sugar category, we would classify dried fruits as high-sugar foods (using the apricot example, the one-quarter cup of dried apricots actually contains more sugar-17.4 grams-than the entire one cup of fresh apricots, which contain 14.3 grams. While the nutrient richness-the measurement of the amount of a nutrient per calorie-of some nutrients are the same in fresh and dried apricots, fresh apricots are more concentrated in several nutrients because the commercial process of drying fruit in large quantities is very hard on some nutrients. The following chart illustrates some examples:

The other thing to be aware of with commercially dried fruit is the addition of other ingredients, notably sweeteners. These are usually always added to dried cranberries (and oftentimes other berries) since cranberries are very tart. In this example, we'd suggest looking for dried cranberries sweetened with a natural sweetener such as apple juice concentrate rather than refined sugar or corn syrup.

With home dehydrating, however, it's a different story. A home dehydrator does nothing more than blow warm air up through the fresh fruit, and it's not nearly as harsh on the nutrients. (Many people like to start with fresh organic apple slices as a test.) The fruit is still "dried" and lasts much longer than fresh fruit, but it isn't dried in the same manner as a commercial processor would do it. Even though home dehydration is not a bad way to go from an overall nutrient standpoint, we all still need to be careful from the sugar and calories standpoint. Sometimes we might end up eating a lot more dehydrated apple slices, for example, than the amount of apple we would have eaten if we had a fresh, organic, whole apple in our hand. The chewing here and whole experience of eating can be quite different.