Application of Sweeteners in Food and Drinks - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 215

• Pectin. Natural fruit pectin is low in concentration; hence, commercial pectin is usually added.

Pectinisapolysaccharideconsistingofsmallmoleculesofgalacturonicacid.Pectinpowerdiffers
infruits.Hence,inquincemarmalades,pectinshouldnotbeadded,becauseitspectinshavegood
thickeningstrength.Pectinsaredistinguishedasslowandfastthickening.

MarmaladepreparationisshowninFigure8.2andisdescribedasfollows:

• Fruit preparation depends on the type of fruit and the type of product; for example, marmalade

requiresmashedfruits,whereasconiturerequiresthickpulpwithsmallfruitpieces.

• Saccharose to be added is determined by the sugar concentration in the fruit. The inal product

shouldhavetotalsugarsofapproximately65%-70%.

• Boilingiscarriedoutundervacuum.Thepurposeofthisstepistoremovewaterevaporatingthe

producttothedesiredsugarlevel.

• Pectinisaddedjustbeforetheendofboiling.

• Theproductispackagedinglassjarswhilestillwarm(80%-85%).Followinglidinsertion,thejars

arereversedtosterilizetheproduct.Rapidcoolingfollows.Additivesmaybeaddedtothemixture
forbetterpreservation.

8.7 CaNNING FrUIt

Theprocessofcanningfruitisdescribedasfollows:

1. Fillawater-bathcannerwithenoughhotwatertocoverthetopsofthejars.Placethecanneron
heat.

2. Discardunsuitablejarswithcracksorchipsintheirsealingsurface.

3. Scaldthejarsandleavetheminhotwater.

4. Prepareanascorbicacidsolutionandmakeasuitablesyrupforfruit.

5. Washandsortthefruit,selectingirmripefruit.

6. Packthefruitintohotjars.Ahotpackmaybeusedforallfruits.Precookthefruitinsyrup.Pack
boilhotfruitlooselyintohotjars,leavingappropriateheadspace.Coverthefruitwithboilingsyrup,
leavingthesameamountofheadspace.

7. Acoldpackmaybeusedforallfruits,exceptforapples,applesauce,andrhubarb.Packthefruit
irmlyintojars,leavingappropriateheadspace.Pourboilingsyrupintothejar,leavingappropriate
headspace.Packingjarstoofull,withoutadequateheadspace,mayresultinthelossofsyrupfrom
thejarduringprocessing.

8. Removeairbubblesfromilledjarsbyinsertinganarrowmetalspatuladownthesidesofeachjar.
Thishelpsinkeepingthesyrupabovethefruit.

9. Lowerthejarsintothehotwater-bathcanner.Coverthecannerandheat.

10. Counttheprocessingtimewhenthewatercomestotheboil.Keepthewaterboilinggentlyduring
theprocessingtime.

11. Removethejarsfromthecannerwhentheprocessingtimeisup.Cooljarsuprightonafoldedcloth.

12. Test seals when the jars are cold. If the jar is not sealed, the lid will bounce up and down when
pressedatthecenter.

13. Labeljarswithcontents,date,andlotnumberifcanningofmorethanonebatchtookplaceduring1day.

14. Storeinacoolanddryplace.

Thefruittobecannedisplacedinasyrupofgreatersugarconcentrationthanthatinthefruit
itself.Thedissolvedsugarinthesyrupdiffusesintothefruit(osmosis)andimprovesitslavor.As
thefruitcooksinthesyrup,thecellwallsbecomemorepermeable,thefruittexturegrowsmore
tender,andtheretentionofsugarrendersthefruitplumpandattractive.Wholefruitswithtough
skins, such as Kieffer pears and kumquats, are impermeable to the sugar syrup, unless they are
precookedortheskinsarepierced.