05-postharvest handling of avocado (1)

8/14/2019 05-Postharvest Handling of Avocado (1)

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Avocado Postharvest HandlingAvocado Postharvest Handling

Major California Avocado Cultivars

Bacon Fuerte Gwen Hass

Lamb Hass Pinkerton Reed Zutano

External Chilling Injury Internal Chill ing Injury

Susceptibility to low storage temperatures


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Body Rot

Stem End Rot

PostharvestDiseases

PostharvestDiseases

AnthracnoseBody Rot

DothiorellaStem End Rot

AlternariaStem End Rot

What we know about the avocado fruitWhat we know about the avocado fruit

It is a climacteric fruit showing an increase inrespiration and ethylene production during ripening

Influenced by maturity, time after harvest,temperature and atmosphere

0 1 2 3 4 5 6

Days at 68F

0

50

100

150

0

100

200

300

400

Carbon Dioxide

Ethylene

mlCO

2/kg/hr

ulC2H4/kg/hrAdapted from

Eaks (1978) forHass


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68 77 86 95 104

Temperature (F)

50

100

150

0

100

200

300

400

Carbon Dioxide

Ethylene

mlCO

2/kg/hr

ulC2H4/kg/hr

High Temperature Effects on Hass FruitRespiration and Ethylene Production (Eaks, 1978)

Peak respiratory rate and ethylene production.Fruit held continuously at temperature.

Field OperationsField Operations

Minimum Maturity Standards Dry Weight

Harvesting Methods

Bin Holding

Multiple Harvests per year

California switched to Dry Matter in 80s from oilcontent

Relationship between dry wet and oilAlso raised minimum maturity based onsensory evaluation

California switched to Dry Matter in 80s from oilcontent

Relationship between dry wet and oilAlso raised minimum maturity based onsensory evaluation

Work of Lee et al. (UCR)


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Date/Size Maturity Releases

Industry interest in harvestdates by size and variety.

Model developed to predict thedate when dry matter willreach minimum maturity(Ranney et al).

Date/Size maturity releasesallow avocados to move in auniform manner.

Avocados can still beharvested before the releasedates, but they will be testedfor minimum maturitystandard.

DRY MATTER % VARIETIES

17.7 Bacon

18.7 Zutano

18.7 Reed

19.0 Fuerte

20.8 Hass

21.6 Pinkerton

24.2 Gwen

Current California Minimum MaturityStandards (last revised 2/98)

Current California Minimum MaturityStandards (last revised 2/98)

Regulated by CA Dept of Food and Ag

Hass size and release datesHass size and release dates

size 40 and

largersize 48 size 60

size 70

and

smaller

Nov 28 Dec 12 Jan 2 Jan 16

Freeze DamageFreeze Damage

SunburnSunburn


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Fruit clippedTrees are tall ladder workand picking poles requiredBins moved to receivingarea

Fruit clippedTrees are tall ladder workand picking poles requiredBins moved to receivingarea

Bins hold approx. 900 lbs

Considerations in the groveConsiderations in the grove

Avoid picking when temperatures arehigh especially with late season fruit

Avoid picking during or shortly aftera rain event more decay

Keep fruit in a cool place, out of thesun; high temperatures can impactripening and increase decay

Minimize delays from time of harvestto cooling

Packing OperationsPacking Operations

Bins cooled overnight

Dry dump Brushing (waxing)

Labeling/weight sizing

Packing


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Bin Dump

Grading

Labeling and Sizingby weight

Tray PackTray Pack

Volume FillVolume Fill

RPCRPC

BaggingBagging

Shrink WrappedShrink Wrapped

and all combinationsand all combinations


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Box weights calibrated andfinal quality inspection

Palletization

From US packinghouses oftenshipped in mixed loads;Imports either in break bulk vesselsor CA containersMost imported fruit handled by CApackers

Avocado Storage and TransitAvocado Storage and Transit

California fruit marketed within 1 2 weeks ofharvest; storage at 5C

US imports arrivals vary in time after harvest:


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22 24 26 28 30 32 34 36 38 40 42 44

0

10

20

30

40

50

60

70

80

90

100

%U

nsoundfruit(5%t

hreshold)

Age when ripe (days)

2000

2001

2002

y = 0 + 0.02762*exp(days/5.203)

r2= 0.82, n= 50, p


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Ethylene dose considerationsEthylene dose considerations

Ethylene concentration >20 ppm; no more than 100 ppm

Fruit Maturity Less mature; longer treatment

Time after Harvest With increasing time after harvest;

shorter durations needed

How much to apply?How much to apply?

Shortexposures toethylene cantrigger ripening Threshold isbelieved to bearound 10 ppm Commercialapplication of20 - 100 ppm isrecommended

Source: I. L. Eaks, UC, Riverside

10, 100 ppm

1 ppm

0 ppm

Time after harvestTime after harvest

Time afterharvestdecreasesthe impactof ethylene

Average Days to Eating Ripeness (


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Suggested treatment times forCalifornia Hass avocados

Suggested treatment times forCalifornia Hass avocados

Early season fruit (November February) 36 72 hours

Mid-season fruit (March June)24 36 hours

Late season fruit (July October)8 - 24 hours

Time after harvestTime after harvest

Ethylene has maximum benefit within1-2 weeks of harvest

Imported fruit (i.e. Chile) ifconventional shipment will need lesstime (24 hours or less)

Imported fruit if CA or 1-MCPtreated shipped may need longer

treatment times

Management IssuesManagement Issues

TemperatureVentilation/Air exchanges

Careful MonitoringPrompt Movement of fruitWhat is the proper stage ofripeness?Where do you ripen the fruit?


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Temperature ManagementTemperature Management

Efficient warming/cooling of fruitessential Airflow essential to maintain proper

pulp temperature (20C; 68F)

Impact of high temperatures (>21C;70F) Delayed/uneven ripening Increased decay

VentilationVentilation

Buildup of carbon dioxide (inhibitsethylene action)

Airflow essential to maintain properpulp temperature (68F)

Preliminary data suggests that shortdurations of high carbon dioxide (upto 5%) can be tolerated

Problems thatyou can find atthe retail levelin spite ofdoing it right

Problems thatyou can find atthe retail levelin spite ofdoing it right


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Market Fruit Quality SurveysMarket Fruit Quality Surveys

Conducted in collaboration with CAC Merchandising Staff

Example of fruit

shriveling

Example of an

overripe fruit

with stem end

rot, body rot

and internal

bruising

Example of a

stem end rot

Example of

body rots

A.

A. Fruit with no bruising

under the peel.

B. Fruit which is very

overripe and is

exhibiting bruising

under the peel.

A. Very ripe fruit

compressed by other

fruit on display.

B. Example of internal

bruising.

C. Very ripe fruit showing

severe internal

damage.

B.A.

C.

B.


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Squeezing!!!!!a.k.a. compression damage

Squeezing!!!!!a.k.a. compression damage

Fruit squeezed at nearly ripe stage

The average incidence of fruit quality problems judged to

be either slight or moderate to severe

0

10

20

30

40

50

60

70

80

90

100

Fi rmness Shr ivel Int er nal Br ui si ng Br ui si ngunder Peel Body Rot StemEndRot

Observed Problem

% of

total

fruit

Moderateto Severe

Slight

Market Survey, 2005

Considerations for successfulavocado ripening

Considerations for successfulavocado ripening

Temperature managementis CRITICAL Too high; ripening

inhibited and increaseddecay

Too low; ripening is slowedand lose benefit

Fruit Maturity More mature; less time

Time after Harvest After storage; less time

Avoids delays in marketing Minimize fruit handling

Checklist

Quality; dont usestressed fruit

Standardize fruit sizeand maturity

Uniform warming andcooling

Careful monitoring;dont overripenCONSUMER/MARKET Education


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Solving problems at the marketplace

Ethylene treatment of fruit

increasing and becoming animportant tool to make theavocado more consumerfriendly

Consequence of handling ripefruit MORE Physicaldamage

A problem NO MATTER thesource an opportunity towork with other industries

Coordination with HAB?

Limitations to avocadopostharvest handlingLimitations to avocadopostharvest handling

Fruit maturity and quality at timeof ripeness

Time after harvest (fruit age)

Stage of ripeness more difficult

to handle ripe fruit

Additional informationAdditional information

Ripe-Max program

http://avocado.org/merchandising/index.phtml Industry reports

http://avocado.org/growers.phtml

Information on avocados in generalfrom around the worldwww.avocadosource.com

05-postharvest handling of avocado (1)

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