Freezingfruitsandvegetables(Cong Nghe Lanh Dong Rau Qua)

8/3/2019 Freezingfruitsandvegetables(Cong Nghe Lanh Dong Rau Qua)

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Barbara H. Ingham

FreezingFruits &Vegetables

B3278

University of Wisconsin-Extension Cooperative Extension

Wisconsin Safe FoodPreservation Series



Would you like toenjoy bright,crisp garden

green beans all yearlong? How about ripe

juicy raspberries?Freezing fruits andvegetables can be an

easy way to enjoy the bounty of yourgarden and orchard all year round.Follow these guidelines for safepreparation and preservation of peak-

of-the season fruits and vegetables.Compared with other preservationmethods,freezing saves time andnutrients,and keeps fruit s and veg-etables fresh-tasting and colorful.The ease of using frozen food infamily meals adds to their appeal.

To ensure high-quality products,carefully complete each step in thefreezing process.All fruits and veg-etables contain enzymes that candestroy nutrients and change thecolor,flavor and texture of foodduring frozen storage.

Natural acids in most fruit s,plusantioxidants and sugars,help blockenzyme action in fruits.To stopenzyme action,most vegetablesneed a brief heat treatment —blanching in boiling water orsteam — before freezing.

Freezing stops the growth ofmicroorganisms such as bacteria,yeast and molds,but does not

destroy them.Therefore,cleanlinessand sanitary methods of handlingfoods for freezing are important.

Freezing does not improve foodquality.So start with high-qualityfruit s or vegetables harvested at theirpeak.If you cannot freeze themwithin a few hours after harvest,store them in the refrigerator topreserve freshness until they can befrozen.

Some vegetables like sweet corn loseflavor rapidly because their naturalsugars turn to starch after harvest.Broccoli and green peppers can losea good deal of vitamin C if allowed tostand at room temperature forseveral hours before freezing.Berriesand other soft fruits can lose flavor orbecome overripe,so freeze thesequickly.

F R E E Z I N G F R U I T S & V E G E T A B L E S 1

Freeze fruits and vegeta-bles harvested at peakquality. Ideally, you

should freeze produce the day it is har-vested. Freeze only limited amounts offood at any one time.Usually,2 to3 cubic feet of food is all a homefreezer can freeze quickly enough forbest quality.













12 Wisconsin Safe Food Preservation Series

Yield of frozen fruit from freshFor 1 pint frozen Pounds of fresh

Apples 11 ⁄ 4 to 1 1 ⁄ 3 lbs.

Apricots 11 to 13 oz.

Berries, firm 3 ⁄ 4 to 1 lb.

Cherries 11 ⁄ 4 to 1 1 ⁄ 2 lbs.

Cranberries 1 ⁄ 2 lb.

Peaches,nectarines 1 to 1 1 ⁄ 2 lbs.

Pears 1 to 1 1 ⁄ 4 lbs.

Plums, prunes 1 to 1 1 ⁄ 2 lbs.

Raspberries 1 lb.

Rhubarb 1 lb.

Strawberries 14 to 16 oz.

Note: lb.= poundmg.= milligram

oz.= ouncetbsp.= tablespoontsp.= teaspoon

See antioxidants on page 7,syrupsfor freezing fruits on page 8.

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BlanchingVegetable Preparation time*Tomatoes, Wash.Blanch 1 minute to loosen skins, To loosen skins:1crushed peel and core.Simmer 10 to 20 minutes until

tender.Cool and pack in rigid containers,leaving 1 ⁄ 2-inch headspace.

Tomatoes, Whole tomatoes can be wrapped and frozen To loosen skins:1raw if you plan to use them within 3 months.

Wash.Blanch 1 minute to loosen skins,peeland core.Freeze whole or in pieces.Use onlyfor cooking or seasoning.

Turnips, Remove tops,wash,peel,slice or dice in 2parsnips 1 ⁄ 2-inch cubes.Blanch.

Vegetables, Blanch each individual vegetable separately See time formixed as directed above.Freeze on trays.Combine each vegetable.

frozen loose pack vegetables such as limabeans,peas,carrots,sweet corn kernels,broccoli cuts and cauliflower.

* Minutes in boiling water unless noted


VEGETABLEF R EEZ I N G G U I D E

Caution: The volatile oilsin hot peppers can causeburns.Wear rubber

gloves when you cut or chop thesepeppers. Do not touch your face,par-ticularly near your eyes.Wash hands

thoroughly with soap and water if youdo handle hot peppers.

For more information, see Make Your Own Sauerkraut B2087 and Tomatoes Tart & Tasty B2605, available from yourcounty UW-Extension office orCooperative Extension Publications atthe address on the back page.

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N O T E Scdacdaccdacdac



© 2000 by the Board of Regents of theUniversity of Wisconsin System doingbusiness as the division of CooperativeExtension of the University of Wisconsin-

Extension.Send inquiries about copyrightpermission to:Director,CooperativeExtension Publications,201 Hiram SmithHall, 1545 Observatory Dr.,Madison,WI53706.

Author: Barbara H.Ingham,food scienceextension specialist,Department of FoodScience,University of Wisconsin-Madisonand UW-Extension.Based on a previous

publication by Mary E.Mennes (retired),food management specialist, Departmentof Food Science,UW-Madison andUW-Extension.

Reviewers: Julie Garden-Robinson,NorthDakota State University;Linda Harris,University of California-Davis;JudyHarrison,University of Georgia-Athens;Val Hillers,Washington State University;Patricia Kendall, Colorado StateUniversity;Lydia Medeiros,Ohio StateUniversity;Karen Penner,Kansas StateUniversity;William Schafer,University ofMinnesota. Wisconsin reviewers: HelenHarrison,professor,HorticultureDepartment,University of Wisconsin-Madison;Kerry Ingraham,horticultureeducator,Eau Claire CountyUW-Extension;Susie Knoblauch,R.D.,outreach specialist,UW-Madison;TerylRoper,professor,HorticultureDepartment, UW-Madison;Deana Sexson,agriculture agent, Portage CountyUW-Extension;Rita Straub,family livingeducator,Marathon CountyUW-Extension.

Produced by Cooperative ExtensionPublications, University of Wisconsin-Extension: Susan Anderson,designer;Rhonda Lee,editor.

University of Wisconsin-Extension,Cooperative Extension, in cooperationwith the U.S.Department of Agricultureand Wisconsin counties,publishes thisinformation t o further the purpose of theMay 8 and June 30,1914,Acts ofCongress.UW-Extension provides equalopportunities and affirmative action inemployment and programming,includ-

ing Title IX and ADA requirements.If youneed this material in an alternativeformat, contact Cooperative ExtensionPublications at (608) 262-2655 (Voice &TDD),or the UW-Extension Office ofEqual Opportunity and DiversityPrograms.Before publicizing,pleasecheck this publication’s availability.

This publication is available from yourWisconsin county UW-Extension office or:

Cooperative Extension Publications45 N.Charter StreetMadison,WI 53715Toll-free:(877) 947-7827(877-WIS-PUBS)In Madison:262-3346Fax:(608) 265-8052

Internet:http://www.uwex.edu/ces/pubs

B3278 Freezing Fruits & Vegetables(2000) R-6-00-5M-225

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Freezingfruitsandvegetables(Cong Nghe Lanh Dong Rau Qua)