10/2/2017. Most foods can be frozen Retains good color, flavor and nutritive value. Texture can be better than for other methods of food preservation

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1 Adapted from: So Easy to Preserve, University of Georgia Cooperative Extension Service Food Preservation: Canning Salsa, Water-bath Food Preservation canning Most foods can be frozen Retains good color, flavor and nutritive value Texture can be better than for other methods of food preservation Foods can be frozen in less time than they can be dehydrated or canned Fairly simple procedures Adds convenience to food preparation Proportions can be adapted to needs, unlike other methods Kitchen remains somewhat cool and comfortable Texture of some foods is undesirable Initial investment and cost of maintaining a freezer is high Storage space is limited by how much the freezer will hold 1

2 Enzymatic changes Enzymes are small proteins in foods that cause maturity Leads to over ripeness (decay) Are slowed down, but not destroyed during freezing In vegetables Enzymes can be destroyed by heat before packaging and freezing by blanching produce In fruits Enzymes usually controlled by ascorbic acid or other treatment options Fruits are usually not blanched, but can be, but have reduced quality Textural changes The water in food freezes and expands Ice crystals cause the cell walls of fruits and vegetables to rupture, making them softer/watery when thawed Some vegetables with very high water content do not freeze well: celery, lettuce, tomatoes, melons Moisture-vapor resistant Durable and leak proof Do not become brittle or crack at low temperatures Resistant to oil, grease or water Protects foods from absorption of off flavors or odors in the freezer Easy to seal and label 2

3 Name of product Added ingredients Form of food: halves, whole, ground, cups, etc. Packaging date Number of servings or amount Freeze foods at 0 F or lower o 24 hours in advance of freezing large quantities of food, set freezer at -10 F or lower Freeze foods immediately after prep and cooling Do not overload freezer with unfrozen food o Freeze amount that will freeze in 24 hours (2 to 3 pounds of food per cubic foot) Move frozen foods together so they do not thaw when room temperature foods are added to the freezer Place unfrozen foods in coldest parts of freezer Leave space around packages so cold air can circulate When packages are frozen, organize freezer into types of food to easily find foods Arrange frozen foods so that the foods frozen longer can be used first Keep an updated inventory of frozen foods Check thermometer periodically 3

4 Select young, tender, highquality vegetables Sort for size and ripeness Wash and drain before removing skins or shells Wash small quantities at a time, lifting out of water DO NOT SOAK Work in small quantities, preparing as directed Blanching Primary method to destroy enzymes that lead to decay Softens hard veggies to make packaging easier Removes some micro-organisms Under-blanching can be harmful it will stimulate enzymes and not destroy them Check required blanching times for each food Boiling water Use saucepan with lid or a kettle with basket and lid Have 1 gallon water per 1 pound of vegetables Place vegetables in blanching basket Lower vegetables into boiling water, add lid on water should hardly stop boiling or return to a boil within a minute If water keeps boiling, begin timing immediately or wait for water to come back to a boil Blanch for recommended time After blanching cool produce immediately in ice cold water Change water frequently or use running cold water Cooling time should be the same as the blanching time Drain thoroughly 4

5 Steam blanching Use pan 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 upon covering pan Takes one and a half times longer than water blanching. Check times for each food After blanching cool immediately in ice cold water Change water frequently or use running water Cooling time is the same as the blanching time Drain thoroughly Dry pack Pack after the vegetables are blanched, drained and cooled Pack quickly, pushing air out of package as you work toward top of package Tray pack After draining, spread pieces in a single layer on a shallow pan Freeze firm Package quickly, pushing air out as you work toward top of package 5

6 Can be frozen in many forms: whole, sliced, crushed, juiced Choose fruit of peak ripeness and freshness o Immature or overripe both produce lower quality when frozen Wash and work with small amounts at a time to preserve best quality Sweetened packs lead to best texture Ascorbic acid: Most economical Powdered or tablet form Tablets must be crushed well ½ teaspoon powdered ascorbic acid = 1,500 milligrams For tablets, use number needed for desired milligrams (e.g., 3 x 500 milligram tablets = 1,500 milligrams) 1 teaspoon (3,000 milligrams) ascorbic acid to 1 gallon of cool water Ascorbic acid mixtures Commercial products e.g.. Fruit Fresh Usually have some other added ingredients Follow package directions to obtain correct strength of ascorbic acid 6

7 May be used in the packing syrup, juice or water packs May be added just before serving These do not help with color retention or texture, like sugar does Use amounts on product labels or to taste Disclaimer Trade and brand names are used only for information. The Cooperative Extension Service, University of Georgia College of Agricultural and Environmental Sciences and College of Family and Consumer Sciences, and the U.S. Department of Agriculture do not guarantee nor warrant published standards on any product mentioned; neither does the use of a trade or brand name imply approval of any product to the exclusion of others, which may also be suitable. Document use Permission is granted to reproduce these materials in whole or in part of educational purposes only (not for profit beyond the cost of reproduction) provided the author and the University of Georgia receive acknowledgment and this notice is included: Reprinted (or adapted) with permission of the University of Georgia. Andress, E.L Canning acid foods (slides). Athens, GA: The University of Georgia, Cooperative Extension Service. This material is based upon work supported by Cooperative State Research, Education and Extension Service, U.S. Department of Agriculture, under Agreement No Adapted from: So Easy to Preserve, University of Georgia Cooperative Extension Service 7