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Postharvest Handling Of Stone Fruits

Postharvest Handling Of Stone Fruits

Beth MitchamUC Davis

Nectarines, Peaches, Plums

Harvesting California Minimum Maturity Indices for Stone Fruit

Fruit Minimum Maturity Indices

Apricot Color of the external surface area: >3/4 yellowish green or >1/2 yellow

Cherry Entire surface solid light-red and 14 to 16% soluble solids (depending on cultivar)

Nectarine &

Peach

Surface ground color change from green to yellow, shape (fullness of shoulder and suture)

Plum Surface color and flesh firmness (depending on cultivar)

Nectarine Maturity vs. Firmness, soluble solids (SS%), and Titratable acidity (TA%)

Maturity stage

Firmness (lbf)

SS% TA%

US Mature 13-15 8-10 0.9-1.1

CA Mature 10-12 9-11 0.7-0.9

Partially-ripe

6-10 11-13 0.5-0.7

Ripe 2-5 13-15 0.4-0.6

California well mature

Ground Color is used as a maturity/ripeness index for

stone fruits

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US MatureUS Mature

California MatureCalifornia Mature

Nectarine Maturity StagesNectarine Maturity Stages

Full Dark Plum and Full Red Nectarines 

and Peaches 

Acceptability of Nectarines and Peaches Increases with Higher Soluble Solids Content

More Types of Tree Fruit 

• About 70 varieties released per year.

• 50% of the releases are sub acid types.

Crisosto and Crisosto. 2005. Postharvest Biology and Technology 39: 10-18.

Delivering Stone Fruits to Packinghouse: wooden bins are being replaced with plastic bins

Hydrocooling

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Packaging Systems

Ranch Pack Mechanized Pack

20 a 60 G

40 a 250 G

Ranch Packing of Fruit Harvested into Buckets

Set buckets onSet buckets onbucket trailersbucket trailers

Deliver toDeliver topacking areapacking area

Sort, size, and Sort, size, and pack from bucketspack from buckets

Cool andCool andholdhold

Load into Load into refrigeratedrefrigerated

transport vehiclestransport vehicles

DistributeDistribute

Transfer to Transfer to central coolingcentral cooling

Bucket OperationBucket Dump Operation

Tote Dumping

Large‐scale Packing Operation for Stone Fruits

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Mechanized Packing of Fruit Harvested into Bins

Dump bags intoDump bags intofield binsfield bins

Deliver toDeliver topackinghousepackinghouse

Cool and holdCool and holdin binsin bins

Cool andCool andholdhold

Load into Load into refrigeratedrefrigerated

transport vehiclestransport vehicles

DistributeDistribute

MechanicallyMechanicallypackpack

Bin Dump and Pre‐Washing

Brushing and Washing

Water Disinfection•Chlorine and Detergent•Active chlorine•ORP detector

Waxing Operation

Postharvest FungicideStone Fruit Residues (ppm) for

Domestic and International Markets

Chemical Names

TradeNames

UsageResidue*

Tolerance(MRL)

Fludioxonil Scholar 0.5-1 5

Fenhexamid Judge** 1-3 10

Propiconazole Mentor***

0.5-1 2***

Water Disinfection

•Chlorine (calcium or sodium hypochlorite)

•Chlorine dioxide

•Ozone

Water Disinfection

•Chlorine (calcium or sodium hypochlorite)

•Chlorine dioxide

•Ozone

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Brown RotGrey Mold

Mucor Rot

Stone Fruit DecaySour Rot Manual Sorting by Quality

Sizing by Weight Sorting by Size, Color, and Defects

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Tray Pack

Volume Filled Inspection

Forced Air CoolingOptimal Storage Conditions:

‐1 to 1C

90 to 95% RH

Storage Duration:

2 to 6 weeks, depending on 

cultivar

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Postharvest  Shelf Life as Influenced by TemperaturePhysicalDamage

Contamination

Inking or Staining Crisosto et al., 1999. California Agriculture 53(1): 19-23.

InternalBreakdown

Mealiness

Flesh browning

Lack of flavor

Failure to ripen

Lurie and Crisosto. 2005. Postharvest Biology and Technology 37: 195-208.

Effect of Temperature on ‘Carnival’ Peach Internal Breakdown After Storage Plus 2 Days at 20F

0C 2.2C 5C

10C7.2CSmith, W.H., 1934. Cold storage of Elberta peaches. Ice and Cold Storage. 37, 54-57.Crisosto, et al., 1999. Susceptibility to chilling injury of peach, nectarine, and plum cultivars grown in

California. HortScience 34(6):1116-1118

Killing Temperature Range

Internal Breakdown Timing

WEEKS

1 2 3

PE

RC

EN

T

0

20

40

60

80

100

Mealiness (visual)Mealiness (taste)Flesh Browning

Carlos Crisosto

ControlledDelayedCooling

5C 20 Days

0C 20 Days 20C 48 Hours + 5C 20 Days

(43%  Mealy) (0% Mealy)

(100%  Mealy)

Crisosto, Carlos H., David Garner, Harry L. Andris, and Kevin R. Day.  Controlled delayed cooling extends peach market life.  HortTechnology 14:99‐104.

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Rate of Flesh Softening (lbs‐force/day)How early can we pick?

‘Tulare’

Red Mahogany

Dark Mahogany

At Harvest

Fir

mn

ess

(g

)

150

175

200

225

250

275

300UntreatedGA

Salmon Red Mahogany Dark

So

lub

le S

olid

s (%

)

10

15

20

25

Mahogany

Cherry PittingCherry PittingCherry BruisingCherry Bruising

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DTR

Pit

tin

g (

%)

0

2

4

6

8

10

12

14

UntreatedGA

Salmon Red Mahogany Dark

Sh

rive

l (%

)

0

20

40

60

80

MahoganySalmon Red Mahogany Dark

Bro

wn

Ste

m (

%)

0

10

20

30

40

Dec

ay

(%)

0

2

4

6

8

10UntreatedGA

Mahogany

Sensory Cherry Flavor

1 2 3 4 5 6 7 8

So

lub

le S

olid

s C

on

ten

t (%

)

10

12

14

16

18

20

22

GAR ² = 0.77

ControlR ² = 0.98

In Bing, Cherry Color was Closely Correlated to Sensory Cherry Flavor and Soluble Solids Content

2 Before Storage 36.4 19.2 2.2 1.1 131 183

5 45.6 21.8 4.4 0.5 118 173

2 After Storage - - 3.2 1.2 178 180

5 - - 5.0 1.9 144 195

2 Before Storage 36.4 19.2 2.2 1.1 131 183

5 45.6 21.8 4.4 0.5 118 173

2 After Storage - - 3.2 1.2 178 180

5 - - 5.0 1.9 144 195

Time in Evaluation Fruit Temp. °C Stem Browning Firmness g/mmField Time Sun Shade Sun Shade Sun Shade

Time in Evaluation Fruit Temp. °C Stem Browning Firmness g/mmField Time Sun Shade Sun Shade Sun Shade

Effect of Sun Exposure on Cherry Fruit QualityEffect of Sun Exposure on Cherry Fruit Quality

Kupferman 1998Kupferman 1998

Stem browning scale: 0 to 5

Cluster Cutter

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Shower Hydrocooler

Thompson and Grant

Cherry MAP Considerations

Reduced O2 Increased CO2

Beneficial range 3-10% 10-15%

Benefits Firmness retention

Decay control, maintenance of

fresh appearance

Potential for benefits

Moderate Very good

Injurious level <1% >30%

Crisosto and Associates

Efficacy of selected fungicides for control of three postharvest decays of sweet cherry

Fungicide Common NameBrown

RotGray Mold

Rhizopus Rot

Registered

Rovral 50WP Iprodione +++ +++ +++ Cancelled

Scholar 50WP Fludioxonil +++ +++ +++ Yes

Allisan Dichloran + ++ +++ Yes

Elite 45WP* Tebuconazole +++ + ++ Yes

Elevate 50WDG Fenhexamid ++ +++ - Soon

Pristine Mixture +++ +++ +++ Soon

PH-066 Pyrimethanil ++ +++ - Soon?

* - Efficacy of Elite 45WP is rate dependent.

Questions?