Cooked Purees: Vegetables, Applesauce
Most vegetable purees are made by first
cooking the vegetable to soften its tissues,
break apart the cells, and free their thickening
molecules.
Some that develop an
especially suave smoothness have cell walls
rich in soluble pectin, which escapes from
the softened wall fragments during pureeing.
These vegetables include carrots, cauliflower,
and capsicum peppers; more than
75% of the cell-wall solids in capsicum
puree is pectin.
Many root and tuber vegetables
(though not carrots) contain starch
granules, which when cooked absorb much
of the water in the vegetable and make it
less watery.
However, such vegetables are
best crushed gently, without breaking open
the cells.Thorough pureeing that liberates
the gelated starch turns the vegetable into a
super-thick potato gravy, gluey and stringy.