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Simple, Safe, Easy to Learn Freezing Fruits and Vegetables Today’s Topics Basics of freezing fruits and vegetables Preventing fruits from discoloring Blanching vegetables Packaging frozen fruits and vegetables Thawing methods for fruits and vegetables Before preserving any food,
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Today’s Topics Basics of freezing fruits and vegetables Preventing fruits from discoloring Blanching vegetables Packaging frozen fruits and vegetables Thawing methods for fruits and vegetables
Before preserving any food, consider the types of foods your family enjoys and the usefulness of the preserved product in your lifestyle.
Basics for Handling Food Safely • Prevent bacteria from spreading through your kitchen • Wash hands: • Warm water and soap for 20 seconds before and after handling food • Sanitize: Cutting boards, utensils, and countertops • Use a solution of 1 tablespoon of unscented, liquid chlorine bleach in 1 gallon of water
Freezing — Overview Easy, convenient and the least time-consuming Slows growth of microorganisms and chemical changes Preserves the greatest quantity of nutrients
Selection • Vegetables: • Choose young and tender • Over-mature may be hard, tough or flavorless • Fruit: • Fully ripe, but firm • Under ripe may be bitter • Freeze soft, very ripe fruits as purées
Preparing Food for Freezing • Thoroughly wash all fruits and vegetables in cold water- DO NOT SOAK! • Enzymes: • Vegetables: • Destroyed by heat, blanching, before packaging and freezing • Fruits: • Enzymatic browning • Controlled by ascorbic acid (vitamin C) or other additives • Usually not blanched
What is the Freezing Effect? • Textural Changes: • Water freezes and expands foods • Ice crystals cause the cell walls of fruits and vegetables to rupture, making them softer when thawed • Vegetables with very high water content do not freeze well • Ex. Celery, lettuce and tomatoes • Vegetables with lower water content become more compact • Ex. Spinach and broccoli
Freezing Pointers • Check freezer temperature • 0o F for best quality • Freeze foods quickly • Don’t stack food packages until they are solidly frozen
Fruit: Freezing Overview • Frozen in many forms • Whole, sliced, crushed, juiced etc. • Best quality- choose fully ripe, but firm, fruit • Immature or overripe produce lower quality when frozen
Fruit: Preventing Darkening and Discoloration • Best for peaches, apples, pears and apricots • Treat washed and sorted fruit with ascorbic acid (Vitamin C) • 1 tsp of ascorbic acid to one gallon of cool water • Use commercial ascorbic acid mixtures • i.e. Fruit Fresh™ (follow manufacturers directions) • Lemon juice or citric acid solutions
Fruit: Types of Packs • Syrup pack (see fact sheet) • Sugar pack • Best for slices of soft fruits like strawberries and peaches • Dry (Tray) pack • Good for small whole fruits such as berries • Unsweetened and water packs • Artificial sweeteners
Fruit: Dry “Tray” Pack • Fruit pieces may be frozen individually, in single layer, on a tray • Freeze until firm then package in rigid container or bag • Will pour out of container easily when frozen • Fruit pieces do not “clump” as when packed directly into containers or with sugar syrup
Fruit: Thawing for Serving • Timing: • Dry sugar packs thaw faster than syrup packs • Unsweetened packs thaw the slowest • Pointers: • When used in recipes, allow for added sugar and more juice • Not all fruits need to be thawed before using
Vegetables: Freezing Overview • Select young, tender, high-quality vegetables • Sort for size and ripeness • Wash small lots at a time, lifting out of water- DO NOT SOAK!
Vegetables: Water Blanching • Primary method of destroying enzymesin vegetables • Directions: • Boil water in a kettle with lid • 1 gallon water per 1 lb. of vegetables • Lower vegetables into vigorously boiling water. Put lid on. Water should hardly stop boiling or return to a boil within a minute. Start timing the blanching as soon as water returns to a boil. • At end of blanching time, quickly remove vegetables from boiling water and place in cold or ice water bath to stop cooking process.
Vegetables: Steam Blanching • Directions: • Use kettle with tight lid and basket • 1 to 2 inches of boiling water in bottom of pan • Vegetable should be in a single layer in basket • Start timing as soon as the lid is on • Remove from kettle and place in cold or ice water bath • Takes 1 to 1 ½ times longer than water blanching- check times for each food
Vegetables: Cooling After Blanching After blanching in water or steam, cool immediately in cold water Change water frequently or use running water or iced water (1 lb. ice per 1 lb. vegetable) Cooling time should be the same as the blanching time Drain thoroughly
Vegetables: Types of Packing • Dry Packing • Pack after the vegetables are blanched, cooled, and drained • Pack quickly, pushing air out of package as you work towards top • Tray Packing • After draining, spread pieces in a single layer on a shallow pan • Freeze firm • Package quickly, pushing air out as you work
Vegetables: Packaging • Use freezer bags or rigid freezer-safe containers • Squeeze air from bags before sealing • Leave ½ to I inch headspace for expansion in rigid containers • Use only moisture–proof, vapor-proof packaging designed for freezing • Do not reuse cardboard containers or plastic containers from commercially prepared food products • Label and date product
Vegetables: Thawing for Serving Most vegetables can be cooked without thawing Corn-on-the-cob should be partially thawed before cooking so that it will heat all the way through Leafy greens cook more evenly if partially thawed
Recommended Storage Times • Fruits • Most frozen fruits maintain high quality for 8 to 12 months • Unsweetened fruits lose quality faster than fruits packed in sugar or sugar syrups • Vegetables • Most vegetables will maintain high quality for 12 to 18 months at 0°F or lower • Use your home-frozen vegetables before the next year’s crop is ready for freezing
What to do if the freezer stops working: • Keep the freezer closed • If the freezer will be stopped for more than 24 hours use dry ice (if obtainable) or move the food to another freezer • Thawed fruits that still have ice crystals can be refrozen or used in cooking, baking and making jams and jellies • Vegetables containing ice crystals or at 40 ° F or below can be refrozen • Thawed vegetables should be thrown out
Summary Freezing fruits and vegetables is a safe, easy way to preserve foods Wash all fruits and vegetables thoroughly Follow blanching charts for vegetables Use proper procedures and equipment, including freezer-safe materials Use the freezing process that works best for your family meal needs
Questions? “This material has not been peer-reviewed for statewide distribution -- blind peer review pending.”
References: Angell, D., & Shertzer, J.(2009) Freezing Fruits. Cooperative Extension, The Ohio State University. Angell, D., & Shertzer.J.(2009) Freezing Basics. Cooperative Extension, The Ohio State University. Angell, D., & Shertzer, J. (2009) Freezing Vegetables. Cooperative Extension, The Ohio State University. Andress, E., & Harrison, J. (2006) So Easy to Preserve (5th ed.). Cooperative Extension, The University of Georgia.