# 3T - Ripening.ppthghhuughgggggggggggggg

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1. Ripening

2. Ripening–changesoccurinamaturefruiteitherbefore
orafterharvest.
Ripeningtransformsaphysiologicallymaturebut
inedibleplantorganintoavisuallyattractiveolfactory
andtastesensationofedibleform.
Itisanirreversibleevent.
Ripeningrenderstheproductedible.Unripefruitsare
notedibleinmostcases.

3. Ripenedfruitsundergoesmanyphysico-
chemicalchangesafterharvestthat
determinesthequalityofthefruiteventually
purchasedbytheconsumer.
Ripeningistheresultofacomplexchanges,
manyofthemoccurringindependently.

4. Somefruitsripenonthetreeitself,whileothers
ripenonlyafterharvest.
Those,whichdon‘tripenormallyonthetree,drop
offfromthetreeafterattainingmaturityiftheyare
notharvestedintime.
Therearetwocharacteristictypesoffruitripening
thatshowsdifferentpatternsofrespiration.
1.Non-climactericfruitripening
2.Climactericfruitripening
Theterm‘climacteric’isfirstusedbyKiddand
West(1927).

6. Non-climacteric fruits
Fruitsareripenonlywhile
stillattachedtotheparent
plant.
Theireatingquality
suffersiftheyare
harvestedbeforefully
ripebecausetheirsugar
&acidcontentdoesnot
increasefurther.
Usuallyfruitsare
harvestedatripestage.
Climacteric fruits
Fruitsarecontinueto
ripenafterharvest.
Theeatingquality
increasesfrommaturity
toripeningbecausetheir
sugarcontentincrease
further.
Usuallyharvestedat
maturestage.

7. Non-climacteric fruits
Respirationrateisnormaland
slowsgraduallyduringgrowth
andafterharvest.
Climacteric fruits
Thestartofripeningisaccompanied
byarapidorsuddenrisein
respirationcalledasrespiratory
climactericorclimactericpeakor
climactericriseorclimacteric.After
theclimacteric,therespirationslows
downasthefruitripens&develops
goodeatingquality.

8. Non-climacteric fruits
Theriseinrespirationinresponse
toethylenemayoccurmorethan
once.
Internalconcentrationofethylene
islessandlessvaries.
Climacteric fruits
Theriseinrespirationinresponseto
ethylenemayoccuronlyonce.
Internalconcentrationofethyleneis
moreandvarieswidely.

9. Non-climacteric fruits
Maturationandripeningaregradualprocess.
Generally,exhibitgraduallossofgreencolor.
Generally,aromaticcompoundsarelessor
absentinthesefruitafterripening.
Fruitsaremaynotberipenedartificially.
Climacteric fruits
Ripeningoccuronlyaftermaturity.
Generally,exhibitrapidlossofgreen
color(chlorophyll).
Generally,thesefruitsarerichsource
ofaromaticcompoundsafterripening.
Fruitsmayberipenedartificially.

11. Climacteric fruits
1.Cherry
2.Cucumber(mostlyallvegetables)
3.Watermelon
4.Grape
5.Pineapple
6.Citrus(Lime,Lemon,Sweetorange,
Mandarin,Grapefruit,Pummelo)
7.Strawberry
8.Tamarillo
9.Litchi
10.Carambola
11.Nuts
12.Loquat
13.Pomegranate
14.Phalsa
15.Aonla
16.Rambutan
17.Olives
Non-Climacteric fruits
1.Tomato
2.Muskmelon
3.Banana
4.Mango
5.Sapota
6.Papaya
7.Apricot
8.Avocado
9.Blueberry
10.Craneberry
11.Fig
12.Kiwifruit
13.Passionfruit
14.Peach
15.Pear
18.Bael
19.Mangosteen
20.Durian
21.Jackfruit
22.Jujube
23.Plum
24.Rasp berry
25.Persimmon
16. Sapota / Chikku
17. Guava
18.Cherimoya
19.Custard apple
20.Apple

12. Generalized patterns of growth, respiration and ethylene during
development, maturation and ripening

13. Respiration pattern of Climacteric and Non-climacteric fruits

14. Respiration pattern of Climacteric fruits

15. 1.Color
2.Organicacids
3.Texture
4.Taste
5.Aroma
6.Abscission
7.Respirationrate
8.Developmentofsurfacewax
9.Chemicalconstituents
Changes occur during ripening
Changesprogresstillmaximumedibility/taste–thereafter
degradation–unfitforeating.
Changesassociatedwithrespirationfruit.

16. 1. Color
Colorchange–impsignalinmanyfruits&major
criterionusedbyconsumerstodetermineripening.
Marketabilityoffruitdependsontheattractivecolor.
Colorarisefrompigments–carotene,xanthophylls&
anthocyanin.
Carotene&xanthophyllsimpartyellowcolor
Anthocyanin–red,pink,violetcolorinfruits
Mostcommonchange–lossofgreencolor,except
avocado,kiwifruit&grannysmithapple

17. Avocado
Kiwifruit
Granny smith apple

18. Climactericfruits–rapidlossof
greencolor.
Non-climactericfruitsalsoexhibit
lossofgreencolorwithattainment
ofoptimumeatingquality.Ex.citrus
fruitintemperateclimates(butnotin
tropicalclimates).
Greencolor–chlorophyll–complex
structurewithMgelement.Lossof
greencolor–degradationof
chlorophyllstructure–associated
withsynthesisofpigmentsranging
fromyellowtoredviz.Carotenoids,
Anthocyanins,Lycopene

19. Carotenoids
•Unsaturatedhydrocarbons,stablecompounds&
remainintactinthetissue.
•Synthesizedduringthedevelopmentstages,but
maskedbychlorophyll.
•Followingthedegradationofchlorophyll,the
carotenoidsbecomevisible.e.g.Bananapeel.
•Carotenoidssynthesisoccurswiththechlorophyll
degradation.e.g.Asthetomatofruitmatures,the
predominantcarotenoidsynthesizediscarotene.

20. •Anthocyanins
–provideredpurplecolorsFVandflowers.
–watersolublephenolicglucosidesfoundincell
vacuoles(beetroot)&alsointheepidermallayersin
apple&grape.
–producestrongcolorsbutmaskedbycarotenoids&
chlorophyll.
–MatureGrapes,pomegranateproducesanthocyanin.
•Lycopene
–Lycopeneaccumulatesduringripeningoftomato.

21. Factorseffectsfruitcolordevelopment–
•Weather
•Temp
•Humidity
•CHOaccumulation
•Practiceslikeringing/girdlings/basketing
•Manuring–ExcessiveN–delaycolordevelopment
•Irrigation
•Light–Shadedfruitsdon‘tdevelopgoodcolour.

22. Usuallyorganicacidsdeclineduringripening
astheyarerespiredorconvertedtosugars.
Acidscanbeconsideredasreservesourceof
energytothefruit&declineduringgreater
metabolicactivitythatoccursonripening.
ExceptBanana&Pineapple–highestacidity
atthefullripestage.
2. Organic acids:

23. Firmness,crispness,mealiness,juiciness&hardiness
arerelatedtotextureoffruitsandcontrolledbythe
walltowalladhesionofcells.
Thecellwallismadeupofcellulose,hemicelluloses,
calciumpectatae,polyuronoidesandglycoprotein.
Fruitsbecomesoftonripening,mainlyduetothe
dissolutionofpecticsubstancesinthecellwalls.
Thesofteningisduetoenzymatichydrolysisof
polysaccharides.
Theenzymepectinasebreakdownpectinbetweenthe
fruitcellsresultinginsofteningofthefruit.
3.Texture:

24. Tastedependsontheproperproportionof
sugarsandacids&measuredinsugar-acid
ratio(Brix-acidratio).
Acidityandastringencygraduallydisappear,
whilesweetnessincreasesduetoconversion
ofstarchtosugarsduringfruitripening.
Ex.Starchcontentofbananadecreasesfrom
21%to15%inripenedfruit&accompaniedby
accumulationofsugars(sucrose)upto20%.
4.Taste

25. Aromaplaysanimportantroleindevelopmentof
optimaleatingqualityinfruits.
Itisduetosynthesisofmanyvolatileorganic
compoundsduringripening.
Aromausuallydevelopsduringripeningbut
occasionallyinstorage.
Duringripening,enzymesbreakdownlarge
organicmoleculesintosmalleronethatcanbe
volatile(evaporateintotheair)andcanbe
detectedasanaroma.
5. Aroma:

26. Theflavouringcompoundsarediffersinfruitbutall
ofthemarevolatile.
Thearomaoffruitduetomixtureofchemicals,
whichmaybederivedfromaliphaticcompounds,
alcohols,acetates,ketonesoresters&terpinoides.
Flavouringcompoundsincreasesasprogressof
ripening,butneedsspecifictempdependson
fruits.
Majorvolatileformed–ethylene–50-75%oftotal
carboninthevolatiles–notcontributefruitaroma.
Amountofaromacompoundsisextremelysmall.

27. Duringripeningthepectinaseenzymeseperate
thecellsoftheabscissionzone(thelayerofcells
inthepedicelscalledabscissionzone).So,the
cellsinthiszonebecomeweakandtheweightof
thefruitwillcauseittofallfromtheplant.
6. Abscission:

28. 7. Development of surface wax:
Waxy/powderysubstancedevelopsonthe
surfaceoffruitslikegrapeandberries.

29. Itisessentialforripening.Ifrespirationisinhibited,
ripeningisalsoinhibited.
Basedonrespirationcharacteristicsoffruits–climactericandnon-climacteric.
Innon-climactericfruitsrelativelylow&consistent.Thefruitsoftendon‘thavelarge
carbohydratereservesandripeningoccurswhileattachedtotheplant.
Inclimactericfruitsastheripeningproceedstherespirationrateincreasesrapidly
reachingpeak(climactericpeak)afterwhichsubsequentdeclineinrespiration.
8. Respiration rate:

30. Starchishydrolyzedintosugars(Glucoseand
fructose),pectin’sbecomesoluble,acids
disappear&tanninsresponsibleforastringency
areeliminatedbytheactionofenzymes.
9. Chemical changes:

31. 1.Temperature
2.O
2
3.CO
2
4.Radiation
5.Humidity
6.Growth regulators
7.Harvesting
8.Chemicals delays ripening
Factors influencing ripening

32. 1. Temperature:
Fruitsharvestedatrighttimegenerallyripenatany
tempbetweentwocriticallimits.
Incertaincasesfruitsmayrequireacoldtreatment
beforebeingplacedinthetemplimitforripening.
Tempaffectsthesynthesisofspecificpigments.
Theoptimumandmaximumtempforsynthesisofa
specificpigmentvarieswithspecies.
Ex.Lycopenesynthesisintomatoisinhibitedat30
o
C,
whereasinwatermelonsynthesisisnotprevented
untilthetemprisesabove37
o
C.

33. 2. CO
2:
ElevatedlevelsofCO
2willinhibitripeningdue
todecreaseinrespiration.
3. O
2:
ReducedlevelsofO
2inhibittheripening.
TheuseofelevatedCO
2&reducedO
2levels
inrefrigeratedstorageextendshelflife.
O
2isessentialforcarotenoidsynthesisand
increasingO
2enhancesthesynthesisofthis
pigment.

34. Mayactasinhibitors/stimulatorsofripening.
Ex.Grapes–infraredradiations–enhancesripening
Banana–X-rays–decreasesofteningbutincrease
inskinblackening.
4. Radiation:

35. 5. Humidity:
RHandvelocityoftheairinfluencesfruit
maturity,especiallyintheevolutionofflavour.
Ex.Saturatedairhindersthedevelopmentof
goodflavourinpearsandinapplesshow
blackeningofcore.

36. Stimulate/inhibitripening.
Effectivewhenappliedatveryearlyafterharvesting.
Bananasimmersedin1000ppmsolutioncontaining
Na,2,4-D,2,4,5-TorPCPA(Para-chloro-phenoxy
aceticacid)–acceleratesripening.
2,4,5-T&2,4-Dsprayedwithwaxemulsiondelayed
thedevelopmentofyellowcolourintherindof
lemonsduringstorage&storagelifeincreases.
Ethephonpromotesde-greening&ripeningingrape,
tomato,coffee,pear,plum,peachandcitrus.
Smokingiscommerciallyemployedtohastende-
greening&ripeningofbananaandmango.
6. Growth regulators:

37. CaC
2releaseacetyleneonhydrolysis–hasten
ripening.
ABA1ppm,Thio-urea20%,CCC4000ppm,ethrel
200-300ppmsprays1weekbeforeharvest–hasten
ripening.
Auxinsmayslowdown(generally)oreven
sometimesaccelerateripeningprocess.
Ethyleneformationisinhibitedbyauxinsand
auxinsbrokendownbyperoxidases(IAA
oxidases)tocontrolfruitripening.Ripening
accompaniedbyriseinauxindegradingenzymes.
Gibberellinsalsostopcolourchangesinbanana.

38. AccumulationofABAisalsoassociatedwith
ripening.
Theshelflifeoffruitslikeapple,bananaand
otherscanbeimprovedbystoringthefruitin
lowO
2orbyabsorbingethylenewithasuitable
absorbentlikealumina/silicagelimpregnated
withpotassiumpermanganate.
MH,GA,IAAsprays1-2weeksbeforeharvesting
andpostharvestdipofCycocel,Alar,GA
(150ppm),Vit-K
3(Menadione)KMnO
4,CaCl
2,
Waxoldelaysripening.

39. Timeofharvestingisimportantfactoraffecting
ripeningatwhichcertainfruitsarepre-
climactericorpostclimactericstage.
Detachmentacceleratesripeningoffruitslike
avocadoandappleduetoinhibitionofauxin
synthesiscontributedbytheleaveswhilethe
fruitisattachedtothetree.
Infruitslikecitrus,apples,bananas&avocados
bruisingoftenstimulateripening–careful
handlingatthetimeofharvestisrequired.
7. Harvesting:

40. 1)Kinetin,
2)GA,
3)Auxin,
4)Growthretardant:MH,Alar,CCC,CIPC.
5)Metabolic Inhibitors: Cycloheximide, Actinomycin-D,
Vitamin-K, Malic acid, Ethylene Oxide, CO.
6)Ethyleneabsorbents-
(a)KMnO
4
(b)Fumigantslikemethylbromide
(c)Reactants
8.Chemicals/PGRdelayripening&senescence: