FOOD PRESERVATION TEACHING OUTLINE

Transcription

1 FOOD PRESERVATION TEACHING OUTLINE Why freeze? A. Advantages Simplest Least time consuming Tastes most like fresh B. Disadvantages Cost of freezer and energy to maintain it Freezing Foods SP Revised February 2017 General Tips A. Start with good quality produce must be fresh for best color, flavor, and nutritive value. B. Prepare ready to serve. Cut vegetables into serving size pieces. Peel, core, and slice fruit, etc. C. Use within 1 year or less for best quality. D. Keep inventory and map of freezer. E. Organize your freezer. Store like foods together in baskets or bags. Be sure to label foods. F. Freeze food as quickly as possible for best texture. The higher the water content of the food, the mushier the food will be when thawed. Spoilage A. Not dangerous to health most is quality change in color or flavor. B. Thaw with caution Bacteria still there multiply fast when thawed. C. Enzymes cause toughening, darkening Vegetables blanch to stop enzymes Fruits antioxidants to inhibit browning D. Freezer burn caused by improper wrapping. E. Large ice crystals caused by slow freezing or refreezing. F. Browning of fruits caused by oxidation results in loss of Vitamin C. G. Rancidity of meats caused by improper wrapping. Fat becomes rancid when exposed to oxygen over a longer period of time. H. The lower the temperature of freezer the better the quality. Equipment A. Most will be around kitchen no special needs. B. Packaging Moisture/vapor resistant, food grade Strong, durable, leak proof Not become brittle and crack at low temperatures. Easy to fill, seal, and label. Resistant to oil, grease, or water. Protects food from absorbing off flavors or odors. Easy to store (space and stacking). Page 1

2 C. Vacuum Sealers Work best for dry packs. Help prevent oxidation. To prevent botulism, keep vacuum sealed foods frozen until ready to use, open when thawing to let oxygen in Great for fish. The Freezer A. Selection advantages and disadvantages Upright: 6-22 cubic feet, 3-7 shelves Chest: 6-22 cubic feet Refrigerator-freezer combination: 2-16 cubic feet, make sure it is a true freezer and maintains food at 0 F. Frost-free vs. regular Good rule of thumb for size is to figure 6 cubic feet of freezer space/person. You can figure about 35 pounds of frozen food/cubic foot of freezer space. B. Placement of freezer Convenient for use Cool, dry place Well ventilated C. Care Use a thermometer to test temperature. Leave a freezer bag of ice cubes in freezer. If they melt and refreeze then you know freezer has been off or not working. Defrost regularly. Clean with baking soda water. Tips for Loading Freezer A. Foods added to freezer should freeze within 24 hours (2-3 lbs/cubic foot) B. Best not to stack thawed foods directly on frozen packages. C. Place packages in a single layer until frozen. D. Be sure food is cold before freezing E. Organize freezer (make a map). F. Rotate food. G. Be sure food is labeled. H. Place meat and cooked foods toward back. I. If food does not freeze quickly, it could be a safety concern as well as affect quality. Freezing Fruits A. Select fully ripe not soft or mushy. Best if tree or vine ripened. B. Select varieties suitable for freezing (check seed catalog or ask grower). C. Preparation: wash, sort, trim, discard green or bruised. Sort by size, ripeness, and color. D. Peel, trim, pit, slice appropriately for intended use. Use sanitary method. E. Method of pretreatment and packing Page 2

3 Antioxidants (for light-colored fruits such as peaches and apples) - Powdered or crystalline ascorbic acid available at pharmacy or health food stores. ½ tsp/4 cups water sprinkle over fruit, add syrup at same rate. - Soak fruit in ascorbic acid solution of 6 Vitamin C tablets (500 mg) per gallon of water. - Commercial preparation follow manufacturer s instructions. Packing - Syrup see PNW 214 for recipes. - Sugar be sure sugar is dissolved before packaging fruit. Note: undissolved sugar can grow into large crystals in freezer. - Dry pack. (might like to flash freeze berries and fruit pieces before packaging. - Juice Cover fruit with fruit juice. Orange and pineapple juice is high in ascorbic acid so helps prevent browning. - Water pack. - Pectin pack. 1 package dry pectin and 3 cups sugar will sweeten 3 gallons berries. See SP Preserving Berries. Great for strawberries F. Packaging Crumple wax paper or plastic wrap on top food in containers to fill up head space before placing lid on container. Helps prevent browning and ice crystals forming on top of food. Leave headspace for expansion if using freezing cartons or jar. Not necessary if using freezer bags. G. Labeling Date, contents, how packed. H. Serving Fruit should be served with a few crystals still in fruit piece Freezing Vegetables A. Select top quality young/tender. Harvest early in day or evening. Keep cold until ready to freeze. For best quality 6 hours from field to freezer is recommended. B. Wash and sort in cold water. C. Cut for table use. D. Blanch to stop enzymes which cause undesirable changes in color, nutritive value, flavor, and texture. Boiling water 1 gallon/pound of food (2 gallons/pound of leafy) Best method for broccoli, cauliflower and Brussels sprouts. Heat penetrates better and less strong flavor produced when stored in freezer. Steam takes longer and results in uneven heating Microwave uneven heating ok for small amounts. Be sure to stir. Not recommended for broccoli or cauliflower E. Packing Dry Packing in flat bags or container not more than 1 inch thick for thawing and cooking in microwave. Flash freeze before packaging if you like individual pieces. F. Label and store. G. Thawing no need to thaw before cooking except for corn on cob or if vegetables frozen in large quantities. Thaw with care because frozen vegetables are blanched and considered a cooked low acid food so more susceptible to spoilage that can cause illness. Page 3

4 Freezing Meat, Fish, Poultry A. Selection of fresh meats, fish B. Preparation clean fish, remove viscera immediately. Freeze whole or in service size pieces. C. Freshly harvested meats and poultry should be cooled quickly and allow to age for at least 24 hours before freezing to produce a more tender end product D. Commercially purchased meats from the store should be rewrapped for the freezer for long term storage. E. Packaging (show kinds of paper, double wrap). Butcher wrap Drug store wrap Water pack for fish glazing Vacuum sealing F. Label and store G. Thaw safely General Summary A. Use high quality foods B. Use sanitary conditions C. Be organized and work fast D. Use approved packaging E. Follow recommended instructions Blanching vegetables Use antioxidants for fruit Cool freshly butchered meat before freezing F. Use air tight containers G. Label H. Freeze quickly I. Maintain freezer at 0 F or lower J. Rotate food and keep inventory K. Use foods within recommended time L. Thaw foods properly Page 4

5 Demo Freeze strawberries in several ways. Thaw them at a future lesson to compare the taste, color, and texture. o Sliced sugared, sliced dry (without sugar) o Sliced in sugar/pectin mixture (see recipe in SP Preserving Berries) o Individually frozen whole on a cookie sheet and then packaged Compare different types of packaging. Discuss the advantages and disadvantages of the different containers and wrap. Include information on cost. o Zipper-type sandwich, storage, and freezer weight bags o Plastic freezer cartons vs. recycled cartons (cottage cheese and yogurt containers). o Samples of other freezer bags and containers on the market in your area including glass/plastic freezer jars. o Butcher paper vs. heavy weight foil. Discuss the advantages and disadvantages of vacuum sealers. If you don t own one, ask if a member of the class could bring and demonstrate one. See SP Should I Vacuum Package Foods at Home Discuss the cost of the vacuum bags as well as the safety hazards of vacuum sealing perishable foods and storing them at room temperature. (They re great for dried foods and frozen fish.) Show how to package fruit in a zippered plastic bag and in a carton (topped with a piece of crumpled plastic wrap) or wax paper. Freeze fruit in fruit juices; flash freeze strawberries on cookie sheet then package in pectin/sugar mixture. Show how to freeze vegetables. Demonstrate how to cut broccoli into serving-sized pieces and stir-fry style. Show blanching (in water, steam and microwave) and cooling. Discuss the advantages and disadvantages of each method. Show freezing stir-fry pieces on a cookie sheet then packaging (so they don t stick together). Show how to freeze meat and fish. Demonstrate how to wrap a cut-up chicken (it can be used later in the canning meats class). Show how to freeze fish in water pack and water glaze larger fish (fish can be used in the classes on smoking or pickling). Demonstrate how to wrap and label prepared dishes for the freezer. Show different storage containers. Page 5

6 Benefits of freezing convenient foods Freezing Convenience Foods A. Prepare foods when you have time. B. Use oven more efficiently by baking more than one dish at a time. C. Avoid waste by freezing leftovers. D. Prepare special diet foods and baby food in single serving portions. E. Save time by doubling or tripling recipes. F. Cook in larger quantities/package serving size portions. G. Save money by making own convenience foods. Disadvantages A. Lots of packaging, energy use of freezer. B. Uses more energy to cook, freeze, and reheat. C. Prepared foods have a shorter storage life compared to fruits, vegetables, meat etc. D. Some products do NOT freeze well. Packaging A. Use containers that you can freeze, thaw and cook in. B. Label with instructions. C. Pack in serving size portions. Serving A. Foods that were cooked and frozen should be reheated to 165 F. B. Thaw in refrigerator or microwave for perishable foods non perishable, bread, cookies, etc at room temperature in wrap. Tips A. Try small amounts before you do large batches. B. Use within 3-6 months. C. Quality will be much better if stored at 0 F and below. D. Select freezer designated containers. E. Vegetables should be blanched. F. Pasta cooked ¾ done (wash, drain, and freeze). G. Meat cooked to just done. H. Freeze seasonings separate. I. Be sure food is cold before freezing. Page 6

7 Foods that Freeze Well A. Baked Products (both baked and unbaked) Cookies and cookie dough Quick breads Waffles Cakes Pies, baked and unbaked (clear-jel) B. Main Dishes Soups (not cream based) Casseroles/entrees Skillet meals Pasta dishes Frozen dinners C. Potatoes Twice baked Scalloped Mashed potato balls Raw potatoes do NOT freeze well Foods that do NOT Freeze Well A. Creamed vegetables B. Potatoes in soups and stews (mushy, rubbery) C. Meringue D. Milk sauces and soups E. Mayonnaise F. Potato salad G. Sour cream/yogurt Freezing Lab Set up stations to freeze a variety of convenience foods. Skillet meal (meal in a bag) PNW 296 Page 9 Twice baked potatoes (Have potatoes prebaked and kept warm) Cookie dough Apple crisp or Clear-Jel made pie Serve them several weeks later for a potluck. Page 7

8 What to Do if Power or Freezer Fails 1. Keep door closed. 2. Insulate freezer with blankets. 3. Add dry ice. 4. Keep freezer full at all times (even if it is frozen water bottles). 5. Use commercial locker or move food to friend or neighbor s freezer. 6. Review SP If Your Home Freezer Stops What Is Safe & What Is NOT 1. Safe to refreeze food that still has ice crystals in it OR temperature is 40 F or below. 2. Caution foods Cooked foods including blanched veggies and convenience foods Fish that has completely thawed Creamed foods and ice cream 3. Ok to refreeze Fruits Breads and pastry (if not molded) 4. Always check foods in freezer that is not working before refreezing Developed by Nellie Oehler, Extension Family and Community Development, Lane County 2017 Oregon State University. OSU Extension Service cooperating. OSU Extension Service offers educational programs, activities, and materials without discrimination based on race, color, religion, sex, sexual orientation, national origin, age, marital status, disability, or disabled veteran or Vietnam-era veteran status. OSU Extension Service is an Equal Opportunity Employer. Page 8