Apples grow primarily in the northern temperate zones of Europe, Asia and North America.
The apple is one of the most important types of fruit in Europe. Roughly 20,000 different varieties are cultivated world-wide, although only a few are economically significant. Apples are pome fruits that grow on small summer-green trees or bushes.
Apples are generally harvested long before they are considered ripe enough for consumption. The latter point is reached when the starch has disappeared almost completely from the flesh and the aroma as well as the sugar and acid content have reached optimal levels. There is a great deal of truth in the old saying that “An apple a day keeps the doctor away”. Apples contain large amounts of fibre (especially in the skin), which is believed to help regulate digestion as well as blood-fat and blood-sugar levels, among other beneficial effects. Since they also contain vitamin C and calcium, juice made from apples is especially nutritious.
Apples vary in colour from red to green, depending on the variety. The skin of the nearly round fruit is edible. Apples have white flesh and dark-brown seeds.
Depending on the type, apples have a typical, ordinarily sweet-tart flavour that results from the interplay of sugar, acids and aromatic substances. Differences in acid content are so marked that juice producers can make especially mild fruit juices, fruit beverages and smoothies from carefully selected varieties. Apples should be allowed to ripen further after picking in order to develop their full flavour.