05-Postharvest Handling of Avocado (1)
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Transcript of 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