Pectin is a natural polysaccharide soluble dietary fiber that is used as a thickening agent in jams, jellies and preserves. It also may help stabilize glucose levels, lower cholesterol levels, reduce heart disease and prevent gallstones. Present in varying degrees in all plants, pectin is present in particularly high amounts in under-ripe fruit such as green apples, grapefruits, oranges and blackberries. Cooking brings out the gelling ability of pectin, but overcooking destroys it.
Citrus Fruits
All citrus fruits -- grapefruits, oranges, tangerines, clementines -- contain a high amount of pectin in the peel, but very little in the fruit itself. According to the Cholesterol Database website, 60 to 70 percent of the dietary fiber found in citrus fruits comes from pectin.
Sour Fruits
Crab apples, sour apples, unripe blackberries, gooseberries, loganberries and cranberries are high in pectin. The pectin content in all fruits is higher when the fruit is barely ripe and decreases as the fruit ripens. Jam and jelly recipes often call for 3/4 ripe fruit and 1/4 unripe fruit to balance flavor, sugar content and pectin.
Other Fruits
Grapes, plums and quince have high levels of pectin, while elderberries, chokecherries, loquats and cherries have some pectin. Adding an acid, such as lemon juice, helps to draw the pectin out of fruit.
