Transcript Nutrition Now J. Brown

Understanding Food
Chapter 17:
Vegetables
Classification of Vegetables
• Webster’s dictionary
refers to vegetables as
“any plant,” but more
specifically as those
that are edible.
• Vegetables may be derived
from almost any part of a
plant:
– Roots
– Bulbs
– Stems
– Leaves
– Seeds
– Flowers
Composition of Vegetables
• Plant pigments fall into three major groups:
– Carotenoids
– Chlorophylls
– Flavonoids
• Carotenoids and chlorophylls are found in
plastids and are fat soluble.
• Flavonoid pigments are water soluble, and
have a tendency to be lost in cooking water.
Preparation of Vegetables
Vegetables can be
prepared by:
• Dry-heat methods
– Baking
– Roasting
– Sautéing
– Deep-fat frying
• Moist-heat methods
– Simmering
– Steaming
– Microwaving
Preparation of Vegetables
• Regardless of the cooking method or serving style
selected, some general principles governing the
handling and preparation of vegetables should be
followed:
– Buying
– Storage
– Washing
– Cooking liquid
– Timing
Preparation of Vegetables
• When heated, vegetables undergo several changes in:
– Texture
– Flavor
– Odor
– Color
– Nutrient retention
• Understanding these phenomena can help to retain as much
of their quality as possible during preparation.
Storage of Vegetables
Refrigerated
• A cooler temperature is
the most important factor
in reducing respiration
rates, and most fresh
vegetables will last at least
three days if refrigerated.
• Storage times for various
vegetables are ultimately
based on their water
content.
• Some vegetables require
special storage treatment.
For example:
– Bean sprouts are best
stored in a bowl of
cold water in the
refrigerator, and the
water should be
changed frequently.
– Ginger root should be
frozen or stored in an
airtight container to
trap its moisture.
Storage of Vegetables
Dry Storage
• Proper storage does not automatically imply refrigeration.
For instance:
– Tomatoes (unripe)
– Eggplant
– Winter squash
– Tubers (potatoes)
– Dried legumes
– Most bulbs (onions)
…should never be stored in a refrigerator.