due to a number of organic acids, notably
oxalic acid, which contributes about a tenth of
the total acidity of 2–2.5%. (This is double or
triple the oxalate content of spinach and
beets.) Rhubarb leaves are said to be toxic in
part due to their high oxalate content, as much
as 1% of the leaf weight, but other chemicals
are probably also responsible. Today rhubarb
is available much of the year thanks to
greenhouse production, though some cooks
prefer the more intense flavor and color of the
field-grown crop of late spring. The color of
red stalks is best preserved by minimizing
both the cooking time and the quantity of
added liquid, which dilutes the pigments.
Fruits From Warm
Climates: Melons, Citrus
Fruits, Tropical Fruits,
and Others
Melons