How to Buy Canned and Frozen Vegetables

                United States Department of Agriculture

               PREPARED BY Agricultural Marketing Service

                  Home and Garden Bulletin Number 259

                        Issue date: January 1994

                               How to Buy

                      CANNED AND FROZEN VEGETABLES


Canned and frozen vegetables, preserved at the peak of goodness, can be
used as an entree...as a side dish in a main meal...or included in
salads, souffles, and other tasty dishes. They are convenient to use and
are always available.

The United States Department of Agriculture (USDA) prohibits
discrimination in its programs on the basis of race, color, national
origin, sex, religion, age, disability, political beliefs, and marital
or familial status. (Not all prohibited bases apply to all programs.)
Persons with disabilities who require alterative means for communication
of program information (braille, large print, audiotape, etc.) should
contact the USDA Office of Communications at (202) 720-5881 (voice) or
(202) 720-7808 (TDD).

To file a complaint, write the Secretary of Agriculture, U.S. Department
of Agriculture, Washington, D.C., 20250, or call (202) 720-7327 (voice)
or (202)720-1127 (TDD). USDA is an equal employment opportunity
employer.


Points to Consider


     Nutritive value...wholesomeness...quality...
convenience...informative labeling...and methods of use are some of the
points to consider when purchasing canned and frozen vegetables.


Nutritive Value


Canned and frozen vegetables provide a variety of vitamins and minerals,
they are low in fat, and they provide fiber. USDA nutritionists
recommend 3 to 5 servings from the vegetable group each day. Count as a
serving 1/2 cup cooked vegetable or 3/4 cup vegetable juice. Salt is
usually added when vegetables are canned, but some salt-free products
are available. Both canned and frozen vegetables are available in butter
or cream sauces, which may be high in fat or salt. Go easy on the fat
and salt added during cooking or at the table in the form of spreads,
sauces, dressings, seasonings, and toppings.


Wholesomeness


When you buy canned vegetables, be sure the cans are not leaking, or
bulged at either end. Bulging or swelling cans indicate spoilage. Do not
taste the contents. Badly dented cans should always be avoided. Small
dents in cans, however, usually do not harm the contents.

Packages of frozen vegetables should be firm. Vegetables should be used
immediately after defrosting to avoid loss of quality. Purchases of
packages that are limp, wet, or sweating should be avoided. These are
signs that the vegetables have defrosted or are in the process of
defrosting. Packages stained by the contents or with ice on the outside
may have been defrosted and refrozen at some stage in the marketing
process. The contents may be safe to eat, but refrozen vegetables will
normally not taste as good as fleshly frozen vegetables.


Grades for Canned and Frozen


Vegetables


All canned and frozen vegetables are wholesome and nutritious, but they
can differ in quality. The difference in quality may mean a difference
in taste, texture and appearance of the vegetable, and its price.
Because different qualities of vegetables are suited to different uses,
you can make better buys by choosing processed vegetables of the quality
that fits your needs.

The U.S. Department of Agriculture's Agricultural Marketing Service has
established U.S. grade standards as measures of quality for many canned
and frozen vegetables. USDA also provides an inspection service which
certifies the quality of processed vegetables based on these U.S. grade
standards. The inspection service is voluntary and paid for by the user.
Under the program, processed vegetables are inspected by highly trained
specialists during all phases of preparation, processing, and packaging.

The grade standards are used extensively by processors, buyers, and
others in wholesale trading to establish the value of a product
described by the grades. If you've been selecting canned or frozen
vegetables by habit, or can't tell which can or package would be best
for the use you have in mind, here's some information that can help you
make a wise choice.


U.S. Grade A

Grade A vegetables are carefully selected for color, tenderness, and
freedom from blemishes. They are the most tender, succulent, and
Flavorful vegetables produced. The term "fancy" may appear on the label
to reflect the Grade A product.


U.S. Grade B

Grade B vegetables are of excellent quality but not quite as well
selected for color and tenderness as Grade A. They are usually slightly
more mature and therefore have a slightly different taste than the more
succulent vegetables in Grade A.


U.S. Grade C

Grade C vegetables are not so uniform in color and flavor as vegetables
in the higher grades, and they are usually more mature. They are a
thrifty buy when appearance is not too important, for instance, if you
are using the vegetable as an ingredient in a soup, stew, or casserole.

Other names may be used to describe.the quality grades of canned or
frozen vegetables--Grade A as "Fancy," Grade B as "Extra Standard," and
Grade C as "Standard."

The brand name of a frozen or canned vegetable may also be an indication
of quality. Producers of nationally advertised products spend
considerable money and effort to maintain the same quality for their
brand labels year after year. Unadvertised brands may also offer an
assurance of quality, often at a slightly lower price. Many stores,
particularly chain stores, carry two or more qualities under their own
name labels (private labels).


Labels

When a product has been officially graded under continuous inspection,
labels may carry the official grade name and the statement "Packed under
continuous inspection of the U.S. Department of Agriculture." The grade
name and the statement may also appear with shields or without shields.

You may find USDA grade shields on cans or packages of vegetables that
have been packed under continuous USDA inspection.

Sometimes the grade name, such as "Grade A," is indicated on the label
without the "U.S." in front of it. A canned or frozen vegetable with
this designation must measure up to the quality stated, even if it has
not been officially inspected for grade.

Federal regulations require that the following information be included
on the label of a can or package:

   * The common or usual name of the vegetable.

   * The form (or style) of vegetable, such as whole, slices, or halves.
     If the form is visible through the package, it need not be stated.

   * For some vegetables, the variety or color.

   * Liquid in which a vegetable is packaged must be listed near the
     name of the product.

   * The total contents (net weight) must be stated in ounces for
     containers holding 1 pound or less. Weight must be given in both
     total ounces and in pounds and ounces (or pounds and fractions of a
     pound) for products containing a net weight of 1 to 4 pounds.

The net weight shown on a label includes both vegetables and liquid. For
the best buy, figure out the cost per ounce. Large containers often cost
less per ounce, but not always. Other information required on the label,
although not on the front panel, is:

   * Ingredients, such as spices, flavoring, coloring, or N special
     sweetener, if used.

   * Any special type of treatment.

   * The packer's or distributor's name and place of business.

   * Nutritional information.

   * Labels may also give the quality or grade, count, size, and
     maturity of the vegetables, cooking directions, and recipes or
     serving ideas. If the label lists the number of servings per
     container, the law requires that the size of the serving be given
     in common measures, such as ounces or cups.


Commercial Processing

Vegetables for canning and freezing are grown especially for that
purpose, and the processing preserves much of their nutritional value.
Both canning and freezing plants are usually located in the vegetable
production areas so the harvested vegetables can be quickly brought to
the plant for processing while fresh and at their peak in quality.

In today's modern plants, most of the processing is done by automated
equipment and there is little handling of the vegetables by the plant
workers. This high-speed process brings us sanitary, wholesome products,
preserved with good flavor and quality.

The initial work in preparing canned or frozen vegetables is similar. At
the processing plant, the fresh product is usually sorted into sizes by
machine and washed in continuously circulating water or sprays of water.
Some vegetables, such as carrots, beets and potatoes, are mechanically
peeled. Next, they are moved onto conveyer belts where plant workers do
any additional peeling or cutting prior to preparation for the various
styles (whole, cut, sliced, etc.).


Canned Vegetables

Cans or glass jars are filled with vegetables by semi-automatic or
automatic machines. Next, the containers are moved to machines that fill
them with the correct amount of brine or liquid and then to machines
that pre-heat them prior to automatically sealing them. The sealed
containers are then cooked under carefully controlled conditions of time
and temperature to assure that the product will keep without
refrigeration. After the containers are cooled, they are stored in cool,
dry, well-ventilated warehouses until they are shipped to market.

Vegetables sold in glass jars with screw-on or vacuum-sealed lids are
sealed tightly to preserve the contents. If there is any indication the
lid has been tampered with, return the jar to the store and report the
matter to the store manager.


Frozen Vegetables

After initial preparation, vegetables that are to be frozen are usually
blanched, or slightly pre-cooked. This pre-cooking process ensures that
the frozen vegetables will retain much of their natural appearance and
flavor for long periods of time in storage. Without blanching, the
product would prematurely turn brown or oxidize before it could be
marketed. The vegetables, after freezing, are packaged in polyethylene
bags of varying sizes or may be packaged in retail-size fiber cartons
with a labeled over-wrap that identifies the product.


Sizes and Servings

Deciding which size can or package you should buy is sometimes
difficult, because canned and frozen vegetables are packed by net weight
rather than volume. Also, the amount obtained from a particular size of
container varies according to the styles of vegetables and different
ways of using them.

Industry terms for containers of canned vegetables are sometimes given
in recipes. Common fiber carton sizes for frozen vegetables range from 8
to 32 ounces, with equivalent metric weights provided in parentheses.
Vegetables packaged in large plastic bags are usually from 16 ounces to
32 ounces. You may find it more economical to buy the large plastic bag,
because you can use part of the contents for one meal and put the rest
back in your freezer to serve later.


Home Storage

Proper storage is important in maintaining the quality of processed
vegetables. If you keep unopened canned vegetables in a place no warmer
than 75 F., they will usually retain their quality for a year or more.
The color, flavor, and texture of canned vegetables that have been
stored at very high temperatures or for prolonged periods of time may
not stay at top quality, but the vegetables will still be safe to eat.
Once a can has been opened, the vegetables should be refrigerated if it
is not for immediate use. Vegetables stored in a refrigerator usually
will keep well for only a few days.

To maintain the quality of frozen vegetables for a longer period of
time, store them in a freezer that can maintain a temperature of 0 F.
or lower. If you wish to use only a portion of an opened package, be
sure to return the remaining portion to the freezer before it has
thawed.


Styles, Seasonings, and Sauces

Both canned and frozen vegetables are sold in many forms or styles.
Carrots, green beans, potatoes, and other vegetables may be found whole,
cut, sliced, diced, and in other forms.

Whole vegetables generally cost more than cut styles because they are
specially selected for appearance and uniformity of size, shape, and
color. Whole vegetables make attractive servings, either hot or cold.

Short-cut green beans, diced carrots, and tomato pieces are examples of
the least expensive styles of processed vegetables, and the styles that
are best used in soups, souffles, and stews. Many frozen vegetables are
available in butter or cream sauces, with mushrooms, or other garnishes
or flavorings. Some canned vegetables are also available in butter
sauces or with other garnishes, such as tomatoes with green peppers and
onions. Such vegetables, of course, cost more than the plain product,
but let you serve something different without any extra work.


Consumer's Guide

The grade and style of a vegetable, whether or not special seasonings or
sauces are added, all affect the cost of the processed product. It may
determine the best way to serve the vegetable, so you get the most for
your money and the most out of the vegetable.

Selecting the style, seasonings, and sauces is easy enough, because
these are shown on the label. The grade or quality often is not
indicated, but you can learn to tell differences in quality by trying
different processors' or distributors' products.

To help you choose the vegetable that will suit the use you have in
mind, some of the most popular vegetables, along with the styles in
which the vegetables are available, are described in the list that
follows.


Artichokes

Artichoke hearts, the tender inner part of the vegetable, are available
frozen and canned. Artichoke hearts are also packed in vinegar and
sauces, to be used like pickles or hors d'oeuvres. Canned whole
artichokes are also available, and they may be served like the fresh
vegetable. The repeated handpicking necessary to harvest artichokes
makes it a relatively expensive vegetable.


Asparagus

Asparagus is more expensive than other vegetables, because much of the
harvesting and preparation during processing is done by hand. The spear,
or stalk, consists of the stem and head (tip). There are two types of
asparagus: green and white. Green asparagus is canned or frozen; white
asparagus is canned. White asparagus is a delicacy, produced by mounding
earth around the plants so that the stalks develop entirely underground.
Sometimes canned asparagus is packed in glass jars with a note on the
label that a color preservative (stannous chloride) has been added. Some
canned asparagus spears may have shattered heads, because asparagus is
such a delicate product.


Beans, baked, kidney, and-others

Many varieties of mature dry beans are processed by canning. Baked beans
are processed in tomato sauce or brown sugar and molasses, usually with
pork, and cooked in ovens. Small white beans and lima beans are also
available in tomato sauce, sometimes with a small amount of pork or meat
flavoring. Red or kidney beans are prepared in a sweetened sauce or
clear salt brine.

Top-quality, mature dry beans have a smooth sauce, and few broken or
mashed beans are found in a can. Because of the unusually high protein
content and food energy of these vegetables, they may be used as main
dishes as well as side dishes or ingredients in salads.


Beans, green and wax

Called string beans before the development of string-less varieties, or
snap beans, pole beans, or bush beans when they are fresh, the canned
and frozen products are usually known as green beans and wax beans. Wax
beans are so called because of their waxy yellow color. There is little
difference in nutritional value of the two types of beans, but green
beans are better known. "Blue Lake," a popular variety of green beans
used for canning and freezing, is often named on the can or package.
Italian or "Romano" green beans are large flat beans.

Styles of both frozen and canned green and wax beans are: whole,
French-style, cut, and a mixture of cuts of various lengths. Whole-style
beans are sometimes packed vertically in cans. When beans are of about
the same length and packed vertically, they may be labeled "whole
asparagus style." Beans sliced lengthwise are labeled "French-style,"
"julienne," or "shoestring." Beans labeled "cuts" or "short cuts" are
sliced crosswise. Beans cut diagonally are sometimes called "kitchen
cuts" or "home cuts."


Beans, lima

Several types of lima beans are canned and frozen. The Fordhook variety,
a name often shown on labels, is a large, thick bean. Several varieties
of lima beans have small, thin beans. These are usually called baby
limas. Lima beans are white, yellow, or green, depending on the variety
and their maturity when harvested. Each color has its own flavor. Green
limas are usually the youngest beans.

Speckled butter beans are another variety of lima bean, found mostly in
frozen form. They are larger than most other lima beans and have a
different flavor. These beans range in color from green, pink, and red
to lavender and purple, with brown, purple, and other speckling.

Top-quality lima beans are less starchy than the lower grade and baby
limas are less starchy than the larger beans.


Beets

Canned beets are available whole, sliced, quartered, diced, and in
strips. Beets prepared in a slightly thickened, sweet vinegar sauce are
called Harvard beets.


Broccoli

Frozen broccoli is prepared as whole spears or stalks, short spear or
florets (the head with a short portion of the stalk), cuts or pieces,
and chopped.

The highest quality frozen broccoli looks much like the fresh vegetable.
It has compact bud clusters that are dark green or sage green, sometimes
with a decidedly purplish cast. Second-quality broccoli may have
slightly spread bud clusters.


Brussels Sprouts

Brussels sprouts are a member of the cabbage family and they look like
miniature cabbages. They get their name from Brussels, Belgium, where
they originated.

Top-quality frozen Brussels sprouts have tight-fitting leaves and are
free from defects.


Cabbage

Sauerkraut is one form of processed cabbage. The shredded cabbage is
fermented in a brine of its own juice and salt, and it may be flavored
with peppers, pimentos, tomatoes, and various spices. It is available
canned and in refrigerated packages, and, at times, a semi-fresh product
is sold from barrels or similar containers. "Sweet and sour" red cabbage
is also sold.


Carrots

Canned and frozen carrots are available whole, quartered, diced, as
strips, round slices (cuts), and chips (frozen only). Canned small baby
whole carrots are especially flavorful.


Cauliflower

Frozen cauliflower is separated into florets before it is frozen.
Top-grade cauliflower is white to creamy-white while the lower grade
often looks slightly gray or brown, but usually turns white when cooked.


Corn

Processed sweet corn is found in various forms, styles, and grades.
Canned corn may be cream style, with large or small pieces of kernels in
a thick, creamy sauce prepared from corn, salt, sugar, water and
sometimes small amounts of starch. Another canned style is whole-grain,
with the kernels generally whole and packed in a relatively clear
liquid. Vacuum-pack is a canning process with whole-grain kernels
intact, but little or no liquid present. Most canned corn is prepared
from yellow or golden-colored varieties, but some white corn also is
canned. "Shoe peg" corn, a whole-grain white corn, has small, narrow
kernels with a distinctly sweet flavor.

Most frozen corn is whole-grain yellow or golden corn. A considerable
amount is frozen on the cob.

Both canned and frozen corn may have peppers or pimentos or other foods
added for flavor or appearance.


Hominy

Hominy is prepared from the mature kernels of sweet corn or regular
field corn. The kernels are soaked and cooked slightly. Then the hard
outer coveting is removed before further processing. Hominy is available
in plastic bags in refrigerator cases, but it is usually canned either
in a brine or as jellied hominy. It is a starchy vegetable like potatoes
or sweet corn and is served hot. Jellied hominy may be sliced and fried
like potato cakes.


Mixed Vegetables

There are many varieties of mixed vegetables available, both canned and
frozen. Most of them contain vegetables of top quality. These blends are
usually more expensive than buying the vegetables individually, because
they require more handling, but they are tasty and convenient to use.

Among the traditional vegetable blends are: peas and carrots, succotash,
and the product called "mixed vegetables."

"Mixed vegetables" are usually a combination of green beans, lima beans,
carrots, corn, and peas. Sometimes diced potatoes are added to this
mixture when the product is canned.

Succotash is a mixture of beans and corn. Canned succotash may contain
cream-style or whole-grain corn and lima or green beans, with or without
tomatoes added. Frozen succotash normally consists of white or yellow
corn and lima beans. The proportion of corn and beans in both canned and
frozen succotash may vary somewhat from packer to packer.

These more traditional mixed vegetable products have been joined by many
new combinations, especially frozen. Among the new frozen blends, which
are sometimes packed with sauces, are peas and small onions; vegetables
for making stew; oriental or other exotic mixtures; and a mixture of
vegetables, such as peas and mushrooms with rice.


Mushrooms

Mushrooms are canned in several styles: whole (including the stems), as
buttons (the top only), sliced, and stems and pieces. They are sometimes
processed in butter, and broiled before they are canned. You may also
find frozen mushrooms in some stores.


Okra

Sometimes called "gumbo," okra is quite popular in the Southern States.
It is often used to flavor and thicken gumbos or thick soups. Since okra
is now available canned and frozen, its use is spreading to other
regions.

Small whole okra pods and pods cut into rings are available both canned
and frozen. Canned, fermented okra is partially fermented in a salt
brine and has an acid, kraut-like flavor. Usually firm, with a bright
green color, canned, fermented okra may be served as a side dish, but is
usually used in soups or other foods. Small okra pods are also available
pickled.


Onions

Whole onions are available both canned and frozen, and breaded onion
rings are available frozen. Canned whole onions are usually packed in a
salt brine. Top-grade canned and frozen onions are specially selected
for variety, size, and shape so that they will keep their good
appearance during processing.


Peas, Southern varieties

Several varieties of peas are known as black-eyed or Southern peas, and
sometimes by other names such as "cream" and "purple hull." These
immature, succulent peas are both canned and frozen. Sometimes a few
"snaps," tender pieces of the pod, are included with the peas for flavor
or garnish. Some canned Southern peas are prepared from mature dry peas.
These peas are somewhat starchy and have a different flavor.


Peas, green

Either canned or frozen, peas are one of the most popular processed
vegetables. Different varieties are grown for the two methods of
processing, because of the different effects of canning and freezing on
flavor and color. Two types of peas are used for canning: the
smooth-skinned, early or early June type, and the dimple-skinned or
sweet type. Most peas for freezing are of the sweet type, especially
developed for deep-green color.

Many canned peas are sorted for size: tiny, small, medium small, medium
large, large, or extra large. Sizes are often shown on the label.

"Garden ran" or "field ran" means no size separation has been made.
"Assorted sizes" means two adjacent sizes. "Mixed sizes" means three or
more sizes. "Sifted" means that some sizes have been removed.

Frozen peas are not usually sized, although a limited supply of
excellent-quality small round or early June type peas is frozen.

The higher quality canned peas are tender and flavorful. Their color is
the typical soft pea-green and their packing liquid is slightly green
and water-like. Off-color peas are rarely found in a can. Lower grades
of canned peas tend to be mealy and do not taste as sweet, although they
are not off flavor. Their color may be variable with a few off-color or
broken peas in a can. Also, the liquid may be slightly cloudy, or light
green.


Peppers

Both green and red peppers are frozen whole, with or without stems, as
well as halved, sliced, and diced. Frozen peppers are convenient to use
for stuffing or a garnish. Red and green peppers are sometimes available
canned.


Potatoes

Processed white potatoes are available in many forms, including canned,
small whole, or sliced potatoes and french-fried shoe strings,
vacuum-packed and ready-to-eat. Frozen potatoes, in many sizes and
shapes, are available either fried or unfried. The frozen unfried
products are ready-to-cook patties and whole, sliced, diced, or shredded
potatoes. Frozen french fried potatoes include the ever-popular strips,
sliced or diced products, patties, and puffs. Most frozen french fries
for home use are designed for preparation in the oven, although deep or
shallow frying also produces excellent results.

Top-quality frozen french fries can range in length from 2 to 3 inches,
although the length of the french fries in individual packages should be
fairy uniform. Top-quality french fries also have a uniform color (from
light to medium brown when "fried"). They are uniform in shape and have
few if any defects such as dark spots and pieces of peel. Texture may
vary a little from brand to brand depending on the variety of potato
used by the packer, but french fries should be tender, cooked
throughout, and not soggy. Traditional french fries are moderately crisp
on the surface while shoestrings and dices may be quite crisp
throughout.


Spinach and Other Greens

Various leafy greens are available in canned or frozen form. Among them
are spinach, collards, kale, mustard, turnips (with or without immature
roots), poke salad, endive, and Swiss chard. Spinach is processed whole
leaf, cut leaf, and chopped styles, sometimes with various sauces and
flavorings. The highest grade of these products is produced from young,
tender plants.


Squash

Canned and frozen summer squash is prepared from small succulent
squashes usually cut crosswise. Several varieties are available,
including the flavorful zucchini.

Canned and frozen winter squashes, very similar to pumpkin, are usually
cooked and ready for use as a vegetable or in a pie filling.


Sweet Potatoes

Processed sweet potatoes come in many forms. Canned sweet potatoes may
be vacuum-packed (without any liquid), in a syrup with or without
garnishes like mandarin oranges and pineapple, or solid pack (lightly
packed with little liquid). They are canned in the styles of whole,
halved, mashed, or as pieces. Frozen sweet potatoes are available whole
or halved, baked, stuffed in a shell, sliced, french cut, diced, mashed,
and sometimes formed into cakes.


Tomatoes

Canned tomatoes are usually peeled and packed in their own juice, but
they may have some added tomato pulp or semi-solid paste. The higher
grades have a better color, usually more whole than broken pieces, and
are practically free from peel, core, and other defects.

Many canned tomato specialties are also available. They include pear or
plum-shaped tomatoes and slices, dices, and wedges which are firm and
have little juice. Many of these can be used in salads. Other
specialties are: stewed tomatoes, which contain onion, pepper and other
flavorful ingredients; tomatoes and okra; tomatoes and hot peppers; and
crushed tomatoes.


For information about nutrition, write:
U.S. Department of Agriculture,
Human Nutrition Information Service,
6505 Belcrest Road,
Hyattsville, MD 20782.


Use the Food Guide Pyramid to help you eat better every day...the
Dietary Guidelines way. Start with plenty of Breads, Cereals, Rice, and
Pasta; Vegetables; and Fruits. Add two to three servings from the Milk
group and two to three servings from the Meat group. Each of these food
groups provides some, but not all, of the nutrients you need. No one
food group is more important than another--for good health you need them
all. Go easy on the fats, oils, and sweets, the foods in the small tip
of the Pyramid.

The "Food Guide Pyramid" booklet (U.S. Department of Agriculture, Human
Nutrition Information Service, August 1992, Leaflet No. 572) can be
purchased from the Consumer Information Center, Department 119-A,
Pueblo, CO 81009. Make check or money order payable to the
Superintendent of Documents.


HOW TO BUY CANNED AND FROZEN VEGETABLES

* Look for the U.S. Grade Name

The U.S. Grade name on a can or package means the vegetable has been
packed under continuous USDA inspection. The grade name or the
continuous inspection statement may be shown within the USDA shield.

* Know the Grade

Grade A:

Top quality in tenderness, flavor, appearance, and uniformity. They make
the most attractive servings for special luncheons or dinners.

Grade B:

Very good quality, slightly more mature and not quite as tender as Grade
A vegetables.

Grade C:

Not as uniform in color and flavor as the higher grades and usually more
mature. These vegetables are generally to be used as an ingredient in
soups, souffles, casseroles, stews, etc.

This pamphlet supersedes: HOW TO BUY CANNED AND FROZEN VEGETABLES Home
and Garden Bulletin 167 Agricultural Marketing Service 1977