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Freezing

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Rancidity. Texture Changes. Expansion of food. Ice crystals. 8. Home Food ... Pre-treat as directed to control rancidity, flavor changes or loss of liquid. ... – PowerPoint PPT presentation

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Title: Freezing


1
Freezing
  • Rick Sloan
  • FCS Agent

2
What will we learn?
  • Principles of Freezing
  • Freezers
  • Packaging Materials
  • Freezing Foods
  • Shelf-life of Frozen Foods
  • Emergencies

2
Home Food Preservation
3
Principles of Freezing
3
Home Food Preservation
4
Principles of Freezing
  • Does not sterilize food.
  • Extreme cold (0oF or colder)
  • stops growth of microorganisms and
  • Slows chemical changes, such as enzymatic
    reactions.

4
Home Food Preservation
5
Advantages of Freezing
  • Many foods can be frozen.
  • Natural color, flavor, and nutritive value
    retained.
  • Texture usually better than other methods of food
    preservation.
  • Foods can be frozen in less time than they can be
    dried or canned.

5
Home Food Preservation
6
Advantages of Freezing
  • Simple procedures.
  • Adds convenience to food preparation.
  • Proportions can be adapted to needs unlike other
    home preservation methods.
  • Kitchen remains cool and comfortable.

6
Home Food Preservation
7
Disadvantages of Freezing
  • Texture of some foods is undesirable because of
    freezing process.
  • Initial investment and cost of maintaining
    freezer is high.
  • Storage space limited by capacity of freezer.

7
Home Food Preservation
8
How Freezing Affects Food
  • Chemical changes
  • Enzymes in vegetables
  • Enzymes in fruit
  • Rancidity
  • Texture Changes
  • Expansion of food
  • Ice crystals

8
Home Food Preservation
9
Freezers
9
Home Food Preservation
10
Freezer Selection
  • Consider
  • Size
  • Shape
  • Efficiency
  • Defrosting features
  • Available floor area
  • Amount of freezer space needed

10
Home Food Preservation
11
Freezer Selection
  • What size?
  • General Rule
  • Allow 6 cubic feet of freezer space per person (3
    cubic feet per person might be adequate if other
    methods of food preservation are used).
  • Standard Freezer
  • Capacity -- 35 pounds of frozen food per cubic
    foot or usable space.

11
Home Food Preservation
12
Types of Freezers
  • Upright
  • 6 to 22 cubic feet
  • Convenient
  • Uses small floor space
  • Easy to load and unload

12
Home Food Preservation
13
Types of Freezers
  • Chest
  • 6 to32 cubic feet
  • Takes more floor space
  • More economical to buy and to operate than
    upright
  • Loses less air when opened

13
Home Food Preservation
14
Types of Freezers
  • Refrigerator - Freezer Combination
  • 2 to 6 cubic feet
  • Be sure can set temperature at 0ºF or colder
  • Freezer can be above, below, or beside
    refrigerator area
  • Other features
  • Self defrosting or manual defrost
  • Receptacle clips - prevent accidental
    disconnecting
  • Door locks and drains for defrosting

14
Home Food Preservation
15
Location and Placement of Freezer
  • Place in convenient, cool, dry, well-ventilated
    area.
  • Do not place by stove, range, water heater or in
    the sun.
  • Do not push flush against wall. Leave space for
    air circulation and cleaning.
  • Be sure freezer is level.

15
Home Food Preservation
16
Packaging Materials
16
Home Food Preservation
17
Packaging Materials
  • Moisture-vapor resistant
  • Durable and leak-proof
  • Not become brittle and crack at low temperatures.
  • Resistant to oil, grease, or water
  • Protects foods from absorption of off-flavors or
    odors
  • Easy to seal and mark

17
Home Food Preservation
18
Types of Packaging Materials
  • Rigid Containers
  • Plastic freezer containers
  • Freezer boxes with liners
  • Coffee canisters
  • Wide mouth canning/freezing jars
  • Good for liquids, soft, juicy, or liquid-packed
    foods
  • May be reusable
  • Hold their shape and can be stored upright

18
Home Food Preservation
19
Types of Packaging Materials
  • Non-Rigid Containers
  • Bags
  • Wrappings - cellophane, heavy-duty aluminum foil,
    polyethylene, laminated paper
  • Good for firm, non-juicy foods

19
Home Food Preservation
20
Freezing Foods
20
Home Food Preservation
21
General Freezing Instructions
  • Selection
  • Freezing does not improve quality.
  • Choose the highest quality available.
  • Freeze promptly.
  • Remember some foods do not freeze well.
  • Preparation
  • Work under sanitary conditions.
  • Follow recommended procedures.

21
Home Food Preservation
22
Packing Foods to be Frozen
  • Cool food before freezing.
  • Ice bath
  • Pack in serving size quantities.
  • Usually up to 1 quart
  • Pack foods tightly.
  • Allow for some headspace.
  • Vegetables like broccoli and asparagus, bony
    pieces of meat, tray packed foods, and breads, do
    not need any headspace.

22
Home Food Preservation
23
Packing Foods to be Frozen
  • Press all air from bagged foods, seal bags by
    twisting and then folding over loose edge
    (gooseneck). Secure with string, twist-tie or
    rubber band.
  • Use tight lid on rigid containers and keep
    sealing edge clean. Use freezer tape on loose
    fitting covers.

23
Home Food Preservation
24
Washing Fruits and Vegetables
  • Wash fruits and vegetables in warm water before
    freezer.
  • The only exception to this rule is that
    blueberries should not be washed before freezing.

24
Home Food Preservation
25
Labels
  • Name of product
  • Added ingredients
  • Form of food halves, whole, or ground
  • Packing date
  • Number of servings or amount

25
Home Food Preservation
26
Freezing
  • Freeze foods at lt0ºF (set freezer at -10ºF at
    least 24 hours before freezing foods).
  • Freeze foods immediately.
  • Do not overload freezer with unfrozen food.
    Freeze amount that will freeze in 24 hours -- 2
    to 3 pounds of food per cubic foot.
  • Pack already frozen foods together so they do not
    thaw.

26
Home Food Preservation
27
Freezing
  • Place unfrozen foods in contact with surfaces and
    in coldest parts of freezer.
  • Leave space so air can circulate.
  • When food is frozen, organize freezer into types
    of food.
  • Arrange frozen foods so that the foods frozen
    longer can be used first.
  • Keep a current frozen foods inventory.
  • Check freezer temperature periodically.

27
Home Food Preservation
28
Sweetened Packs for Fruit
  • Syrup Pack
  • Better texture
  • Not needed for safety
  • Fruits should be covered with syrup
  • Place crumpled water-resistant paper in top of
    container

28
Home Food Preservation
29
Sweetened Packs for Fruit
  • Sugar Pack
  • Soft sliced fruits (strawberries, peaches, etc.)
    make on syrup when mixed with the right
    proportion of sugar.
  • Layer fruit and sugar.
  • Allow it to stand for 15 minutes.

29
Home Food Preservation
30
Unsweetened Packs for Fruit
  • Dry Pack
  • Good for small whole fruits such as berries that
    do not need sugar.
  • Simply pack into containers and freeze.
  • Can freeze on a tray first, so pour easily.
  • Pectin Syrup
  • Good for strawberries and peaches.
  • Mix 1 pkg. powdered pectin and 1 cup water. Bring
    to boil, boil 1 minute. Remove from heat, cool,
    and add 1-3/4 cups more water.

30
Home Food Preservation
31
Unsweetened Packs for Fruit
  • Water or Unsweetened Juice Packs
  • Texture will be mushier.
  • Color poorer.
  • Freezes harder, takes longer to thaw.

31
Home Food Preservation
32
Packs for Purees or Juices
  • Pack as is, with or without sugar.
  • Add ascorbic acid if light-colored.

32
Home Food Preservation
33
Artificial Sweeteners
  • Can be used in the pectin syrup, juice, or water
    packs.
  • Or could be added just before serving
  • Do not help with color retention or texture, like
    sugar does.
  • Use amounts on product labels.

33
Home Food Preservation
34
Preventing Fruit Darkening
  • The following work well
  • 1 teaspoon (3000 mg) ascorbic acid to one gallon
    of water
  • Commercial ascorbic acid mixture
  • Heating the fruit
  • The following do not work as well
  • Citric acid solution
  • Lemon juice
  • Sugar syrup
  • Salt/vinegar solution

34
Home Food Preservation
35
Preventing Discoloration during Freezing
  • Ascorbic Acid
  • Is the most economical.
  • Use powdered or tablet form.
  • 1/2 teaspoon powdered ascorbic acid 1500 mg
  • Crush tablets well.
  • Use amount specified for each fruit.
  • In syrup or liquid packs, add powder to liquid.

35
Home Food Preservation
36
Preventing Discoloration during Freezing
  • In sugar or dry packs, dissolve 2 to 3
    tablespoons in cold water and sprinkle over
    fruit.
  • For crushed fruit, purees or juices, mix with
    fruit about 1/8 teaspoon per quart.
  • Ascorbic Acid Mixtures
  • Follow package directions

36
Home Food Preservation
37
Preventing Discoloration during Freezing
  • Citric Acid or Lemon Juice
  • Not as effective
  • May mask flavors
  • Steaming
  • Best for fruits that will be cooked before use
  • Follow directions in freezing publications

37
Home Food Preservation
38
Freezing Vegetables
  • Select young, tender, high-quality vegetables.
  • Sort for size and ripeness.
  • Wash and drain before removing skins or shells.
  • Wash small lots at a time, lifting out of water.
    Do not soak.
  • Work in small quantities, preparing per
    instructions.

38
Home Food Preservation
39
Preventing Flavor and Color Changes in Vegetables
  • Water blanching
  • Use 1 gallon water per pound of vegetables.
  • Place vegetables in blanching basket.
  • Lower into vigorously boiling water.
  • Cover and begin timing.

39
Home Food Preservation
40
Blanching Vegetables
  • Steam Blanching
  • Use kettle with tight lid and basket.
  • Put 1 to 2 inches of boiling water in the bottom
    of pan.
  • Vegetables should be in a single layer in basket.
  • Start timing when covered.
  • Takes 1-1/2 times longer than water blanching.

40
Home Food Preservation
41
Blanching Vegetables
  • Microwave Blanching (not recommended)
  • Enzymes might not be inactivated.
  • Does not save time or energy.
  • Use specific directions and blanch small
    quantities at a time.
  • After blanching, cool immediately in cold water.
  • Change water frequently.

41
Home Food Preservation
42
Types of Pack for Vegetables
  • Dry Pack
  • Pack after blanched, cooled, and drained.
  • Pack quickly, excluding air.

42
Home Food Preservation
43
Types of Pack for Vegetables
  • Tray Pack
  • After draining, spread in a single layer on a
    shallow pan.
  • Freeze firm.
  • After first hour, check often.
  • Pack quickly, excluding air.

43
Home Food Preservation
44
Freezing Meats and Poultry
  • Keep meat or poultry and everything they touch as
    clean as possible.
  • Keep cold until frozen.
  • Never stuff poultry before freezing.
  • Store-bought meats must be over-wrapped.
  • Freeze meats and poultry using the drugstore or
    butcher wrap (drugstore wrap preferred except for
    irregular meat cuts).

44
Home Food Preservation
45
Freezing Fish
  • Pre-treat as directed to control rancidity,
    flavor changes or loss of liquid.
  • Package using one of the following
  • Lemon-gelatin glaze
  • Ice glaze
  • Water

45
Home Food Preservation
46
Lemon-gelatin Glaze
  • Mix 1/4 cup lemon juice and 1-3/4 cups water.
  • Dissolve 1 packet unflavored gelatin into 1/2 cup
    of this mixture.
  • Heat remaining mixture to boiling and add
    dissolved gelatin.
  • Cool, dip fish, wrap and freeze.

46
Home Food Preservation
47
Freezing Prepared Foods
  • Many can be frozen.
  • Follow directions in a credible freezer
    publication.

47
Home Food Preservation
48
Foods that Do Not Freeze Well
  • Cabbage, celery, cress, cucumbers, endive,
    lettuce, parsley, radishes
  • White potatoes
  • Cooked macaroni, spaghetti, rice
  • Egg whites
  • Meringue
  • Icings made from egg whites
  • Cream or custard filling
  • Milk sauces
  • Sour cream
  • Cheese
  • Mayonnaise or salad dressing
  • Gelatin
  • Fruit jelly
  • Fried foods

48
Home Food Preservation
49
Thawing Foods for Serving
  • Fruits
  • Best if served with ice crystals present.
  • Thaw
  • In refrigerator -- 6 to 8 hours per pound of
    fruit in syrup
  • At room temperature -- 1 to 2 hours per pound
  • At room temperature in cool water -- 1/2 to 1
    hour per pound
  • In microwave oven - follow manufacturers
    instructions.

49
Home Food Preservation
50
Thawing Foods for Serving
  • Dry sugar packs thaw faster than syrup packs.
  • Unsweetened packs thaw the slowest.
  • When used in recipes, allow for added sugar and
    more juice.

50
Home Food Preservation
51
Thawing Foods for Serving
  • Vegetables
  • Cook without thawing except partially thaw
    corn-on-the-cob and leafy greens.

51
Home Food Preservation
52
Thawing Foods for Serving
  • Meat, Poultry, and Fish
  • Can be cooked when thawed or frozen (might 1-1/2
    times longer if cooked frozen).
  • Thaw
  • In refrigerator
  • In microwave oven (follow manufacturers
    directions)
  • In cold water (keep water cold)

52
Home Food Preservation
53
Shelf-Life of Frozen Foods
53
Home Food Preservation
54
Vegetable Storage
  • Temperature
  • 0ºF
  • 5ºF
  • 10ºF
  • 15ºF
  • 20ºF
  • 25ºF
  • 30ºF
  • Length of Storage
  • 1 year
  • 5 months
  • 2 months
  • 1 month
  • 2 weeks
  • 1 week
  • 3 days

54
Home Food Preservation
55
Emergencies
55
Home Food Preservation
56
Freezer Emergencies
  • If power will be off, set freezer controls to
    10ºF to -20ºF immediately.
  • Do not open door.
  • Foods stay frozen longer if freezer is full,
    well-insulated, and in cool area.
  • Full freezer -- keeps 2 to 4 days
  • Half full freezer -- 24 hours

56
Home Food Preservation
57
Freezer Emergencies
  • If power interruption will be longer than 1 to 2
    days, use dry ice
  • 50 lbs -- keeps full 20 cubic foot freezer below
    freezing for 3 to 4 days
  • 50 lbs -- keeps half-full freezer for 2 to 3 days
  • Keep dry ice on boards or heavy cardboard on top
    of food.
  • Do not touch dry ice.
  • Do not open freezer.
  • Ventilate room.

57
Home Food Preservation
58
Refreezing Thawed Foods
  • Texture will not be as good.
  • General rule
  • Refreeze if freezer temperature is 40ºF or colder
    or if ice crystals are still present.

58
Home Food Preservation
59
Best Advice for Freezing
  • Freeze foods quickly.
  • Set freezer temperature at -10ºF 24 hours before
    freezing foods.
  • Spread packages out until frozen, then stack.
  • Hold at 0ºF or colder for best quality.

59
Home Food Preservation
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