Transcript preservation ppt

Preservation
1
Canning Jars
• Glass jars
• pint to quart size
• Do not use other jars like mayonnaise jars
• Two piece vacuum caps
– Screw band and a flat metal lid
2
• Preparing jars and Closures
• Hot, soapy water and rinse them
• Submerge in a sink for 10 minutes
• Place in a dishwasher to sterilize and get
them hot
– If it is processed less than 10 minutes you
need to sterilize them
3
• Hot water bath (ten minutes)
• Filling Canning Jars
• Raw pack – pack raw fruit, veggies tightly into
jars
• Hot pack – heat food in water, steam, syrup or
juice
– Pack loosely in jars and cover with cooking liquid
4
• Headspace – space between the food and the
closure of a food storage container
• ½ inch for high-acid foods
• 1 inch for low-acid, pg 408
• ¼ inch for jams and jellies
• Liquid should cover food or it will turn brown
5
Food Spoilage
• Microorganisms – microscopic living
substances
• Bacteria, mold, yeast
• Bacteria – single celled, can cause
diseases
6
• Mold – growth produced on damp or
decaying organic matter
• Yeast – microscopic fungus that can cause
fermentation
• Enzymes –complex proteins produced by
living cells that cause specific chemical
reactions (buttermilk, sauerkraut)
7
• Need to grow:
• 1. food
• 2. moisture
• 3. temperature
8
Canning Foods
• Why?????
• Over abundance in gardens
• Special recipes
• Avoid preservatives
• Seasonal fruit
9
Food used in Canning
• Fruits, vegetables, juices, meats, pickles,
and jellies
10
Pressure Canning
• Use for green beans (low acid)
• Meats, poultry and fish
• Petcock –allows air to be exhausted
• Pressure gauge – measures steam
pressure
11
Processing Time
• Amount of time canned foods remain
under heat
12
• Boiling Water Canning
• For high acid foods like tomatoes, fruits, and
pickled vegetables
• Use a large metal container, fill the water to
•
•
cover jars and to boil freely
Use a cover but don’t lock in place
When water comes to a rolling boil, start time
13
After Canning
• Press center of each lid
• Remove each screw band carefully
14
Check for Spoilage
• Flat-sour – caused by bacteria (looks
normal but acidic)
• Botulism – food borne illness from spore
forming bacteria (improperly processed)
soft and mushy, smells like rancid
cheese
15
• Jelly products
– Made from fruit juice
• Fruit juice
– Jelly bag to extract juice
– Thoroughly washed fruit
16
Ingredients
• Pectin – carbohydrate found in fruits to
make jell
• Acid --- adds flavor and helps to jell
• Sugar – helps jelly become firm and adds
flavor and preserves jelly
17
Making Jelly
• Bring mixture to full boil, remove from
heat, skim off foam
• Pour into jelly jars
18
Other Jellied Products
• Marmalade – tender jelly containing
small pieces of fruit or fruit rind
• Jam – made from crushed fruit
• Preserves – are whole fruits or large
pieces of fruit
19
• Conserves – made from a mixture of
fruits including citrus
• Fruit butters – are not jellied but cooked
and pureed fruit
20
Freezing Foods
• Quick Freezing
• Subjected to temps between -25 & -40
degrees
21
• Equipment
• Chest and upright
• Containers
• Moisture and vapor resistant
• Shape of containers affect how much food
you can store
22
• Freezing fruits
• Can freeze most fruits, wash and separate,
do not soak
23
• Anti darkening Treatments
• Ascorbic acid – prevents color and flavor
loss
– Another name for Vitamin C
• Ascorbic Acid mixtures – contain
ascorbic acid and sugar or with sugar and
citric acid
24
Packing Fruit
• Dry pack – fruit placed in shallow pan
and frozen (may treat with anti darkening
agent)
• Sugar pack – shallow pan and then add
sugar, turn piece until sugar dissolves
• Syrup pack – prepare syrup and chill
25
Freezing Vegetables
• Blanch – placing in boiling water for a
short amount of time
• Prevents vitamin loss, spoilage
• Cool veggies and drain as soon as possible
26
Packing Veggies
• Put in air tight containers as soon as
possible
27
Freezing Meat
• No special preparation
• Do not freeze in original wrappers
• Rewrap in moisture proof and vapor proof
paper
28
Freezing Prepared Foods
• Baked pastry, cookies, breads, etc
• Freeze casseroles, stews
29
Thawing Frozen Foods
• Cook some veggies without thawing
• Does take extra cooking time
30
Food Drying
• Drying removes moisture
• Dry fruit, veggies, meats, etc
• Are lightweight
• Fruit leathers – pliable sheets of dried
fruit puree
31
Preparing to Dry
• Dry food completely to prevent spoilage
• Select young and tender veggies
• Sulfuring is an anti darkening treatment
used on fruits
32
Procedure for Drying
• 1 sun drying
• 2. oven drying
• Trays and screens to help air circulate
33
Storing and Using Food
• Eat in dry or re-hydrated state
• Freeze drying – involves the removal of
water vapor from foods
• Aseptic packaging – food and its
packaging material are sterilized
separately
34
• Retort packaging – food is sealed in foil
pouch
• Irradiation – exposes food to low level
doses of gamma rays, electron beams, or
X rays
35