Best Practices for use of SmartFresh on Pear Fruit

Beth Mitcham Department of Plant Sciences University of California Davis

1-Methylcyclopropene • Cyclic olefin gas • Inhibitor of ethylene binding and action • Effective at nanomolar concentrations • Registered as SmartFreshTM for postharvest use on fruits

CH3

Treated with 300 ppb 1-MCP

Potential Benefits of SmartFreshTM

• Extend storage life in air or CA storage • Reduce development of storage disorders • Enable warmer temperatures in storage to

save energy • Shipment of fruit to tropical climates or

areas without cold chain

Factors Influencing Pear Fruit Response to SmartfreshTM

• Variety • Growing Location • Maturity

– Fruit ethylene production • Temperature during delay after harvest

Differences in Variety Response to SmartFresh

• Bartlett - ≤300 ppb • Anjou - ≤200 ppb • Bosc - ≤300 ppb • Rocha - 316 ppb (report from literature) • Packham - 200 ppb (report from literature) • Abate Fetel - < 300ppb (report from literature)

• Related to the fruit’s general ripening capacity and ethylene production at harvest

Growing Locations

• Pacific Northwest – Bartlett ≤300 ppb

• California – Bartlett 300-600 ppb

0

20

40

60

80

100

Control 1-MCP Control 1-MCP

Harvest 1 Harvest 2

Sene

scen

t Sca

ld (%

)

Solid color = Elevation 150m Patterned = Elevation 610m

Influence of Elevation and Harvest Maturity on Efficacy of SmartFresh to Control Senescent Scald in Bartlett Pears

Wang & Sugar 2015

0

20

40

60

80

Control 1-MCP Control 1-MCP

Harvest 1 Harvest 2

Sene

scen

t Cor

e Br

eakd

own

(%)

Wang & Sugar 2015

Solid color = Elevation 150m Patterned = Elevation 610m

Influence of Elevation and Harvest Maturity on Efficacy of SmartFresh to Control Senescent Core Breakdown in Bartlett Pears

Competition Between SmartFresh and Ethylene

– Internal ethylene levels increase during ripening and reduces 1-MCP efficacy

– Accumulation of ethylene in the 1-MCP treatment atmosphere will reduce efficacy

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CH3

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Methodology

• Early-, mid- and late-season ‘Bartlett’ pears were harvested from two growing regions in CA

• Fruit were cooled to 0oC and exposed to the following treatments for 24 hours at 0oC

Control (no 1-MCP or ethylene) 1-MCP only (600 nL/L) 600 nL/L 1-MCP & 12 nL/L ethylene (50:1) 600 nL/L 1-MCP & 30 nL/L ethylene (20:1) 600 nL/L 1-MCP & 60 nL/L ethylene (10:1) 600 nL/L 1-MCP & 600 nL/L ethylene (1:1)

• Fruit were then ripened at 20oC

Time (days)AH 0 3 6 9 12 15

Flesh

firmn

ess (

lbs)

0

5

10

15

20

AH 0 3 6 9 12 15 AH 0 3 6 9 12 15

ControlSF only50 SF:1 C2H420 SF:1 C2H410 SF:1 C2H41 SF:1 C2H4

Early-season Mid-season Late-seasonSm

artFr

eshT

M trea

tmen

tEth

ylene

chall

enge

Smart

Fres

hTM t

reatm

ent

Ethyle

ne ch

allen

ge

Smart

Fres

hTM t

reatm

ent

Ethyle

ne ch

allen

ge

• SmartFreshTM effects are diminished for later harvests in association with higher ethylene production by fruit

IEC = 0.04 ± 0.01 ppm IEC = 0.16 ± 0.02 ppm

Effect of Ethylene on Response to SmartFresh on Bartlett Pears

IEC = 3.98 ± 1.18 ppm

Control SF only 50 SF: 1 C2H4

20 SF: 1 C2H4 10 SF: 1 C2H4 1 SF: 1 C2H4

Early season fruit Day 9 at 20oC

600 ppb 1-MCP

Predicting an optimal [SmartFreshTM]

Based on observations from the 2010 season

Treatment Ethylene

concentration (ppm) Beginning End End ratio

Control 0.000 0.172 - SF only 0.000 0.056 11:1

50 SF:1 C2H4 0.017 0.086 7:1 20 SF:1 C2H4 0.034 0.108 5.5:1 10 SF:1 C2H4 0.072 0.173 3.5:1 1 SF:1 C H 0 625 1 455 0 5:1

Time (days)-3 0 3 6 9 12 15

Fles

h fir

mne

ss (l

bs)

0

5

10

15

20 ControlSF only50 SF:1 C2H420 SF:1 C2H410 SF:1 C2H41 SF:1 C2H4

Harv

est

Smar

tFre

shSM

trea

tmen

tEt

hylen

e ch

allen

ge

Ethylene build-up in tanks during treatment

Late Season Bartlett Pears

Treatment Ethylene

concentration (µL/L) Beginning End

Control 0.007 0.258

SF only 0.007 0.224

50 SF:1 C2H4 0.019 0.480

20 SF:1 C2H4 0.036 0.547

10 SF:1 C2H4 0.067 0.688

1 SF:1 C2H4 0.650 1.573

‘Late season’ fruit (IEC = 3.98 ± 1.18 µL/L)

Treatment Ethylene

concentration (µL/L) Beginning End End ratio

Control 0.007 0.258 - SF only 0.007 0.224 2.7:1

50 SF:1 C2H4 0.019 0.480 1.3:1 20 SF:1 C2H4 0.036 0.547 1.1:1 10 SF:1 C2H4 0.067 0.688 0.9:1 1 SF 1 C H 0 650 1 573 0 4 1

Ethylene build-up in tanks during treatment

Time (days)-3 0 3 6 9 12 15

Fles

h fir

mne

ss (N

)

0

20

40

60

80

100

Sm

artF

resh

SM tr

eatm

ent

Eth

ylen

e ch

alle

nge

Har

vest

ControlSF only50 SF:1 C2H420 SF:1 C2H410 SF:1 C2H41 SF:1 C2H4

Predicting an optimal SmartFreshTM Concentration Steps involved:

1. Cool fruit to treatment temperature 2. Seal fruit in jars for 12-15 hours 3. Measure the ethylene concentration that accumulates in jars 4. Calculate the concentration of ethylene that would

accumulate around pears in 24 hours 5. Predict an optimal SmartFreshTM concentration: [optimal SF} = 3.5 X [ethylene]

Ability of Pear Fruit to Ripen After SmartFresh Treatment

0

10

20

30

40

50

60

70

Control 1-MCP Control 1-MCP

Harvest 1 Harvest 2

Firm

ness

(N) a

fter 7

d @

20°

C 3 months

5 months

6 months

Solid color = Elevation 150m Patterned = Elevation 610m

Influence of Elevation and Harvest Maturity on Recovery of Ripening Capacity following Treatment with SmartFresh in Bartlett Pears

Wang and Sugar 2015

0

10

20

30

40

50

60

Control 1-MCP Control 1-MCP

Harvest 1 Harvest 2

Firm

ness

(N) a

fter 1

2d @

20°

C 3 months 5 months 6 months

Solid color = Elevation 150m Patterned = Elevation 610m

Influence of Elevation and Harvest Maturity on Recovery of Ripening Capacity following treatment with SmartFresh in Bartlett Pears

Wang and Sugar 2015

Changes in firmness during storage and post-storage shelf-life of ‘Rocha’ pears treated with 312 ppb 1-MCP

Gago et al., 2013

0

10

20

30

40

50

60

70

At harvest

14 14+1 14+2 26 26+1 26+2 35 35+1 35+2

Firm

ness

(N)

Time (weeks)

2.5°C + air 2.5°C + CA 0°C + air 0°C + CA

14 wks = 3 ½ mo; 26 wks = 6 ½ mo., 35 wks = 8 ¾ mo.

Gago et al., 2013

0

20

40

60

80

100

120

At harvest

14 14+1 14+2 26 26+1 26+2 35 35+1 35+2

Inte

rnal

Bro

wni

ng (%

)

Time (weeks)

2.5°C + air 2.5°C + CA 0°C + air 0°C + CA

Incidence of internal browning during storage and shelf-life of ‘Rocha’ pears treated with 312 ppb 1-MCP

14 wks = 3 ½ mo; 26 wks = 6 ½ mo., 35 wks = 8 ¾ mo.

0

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10

15

0

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60

80

0 1 2 3 4 5 6 7 8

Firm

ness

(lbs

.-for

ce)

Firm

ness

(N)

Months in Storage

Control@-1.1°C 1-MCP@-1.1°C 1-MCP@1.1°C

Influence of Storage Temperature and SmartFresh Treatment on Firmness of Anjou pears During Storage

0

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120

140

160

0

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10

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25

30

35

40

0 1 2 3 4 5 6 7 8

Ethy

lene

Pro

duct

ion

(pm

ol k

g-1 s

-1)

Inte

rnal

Eth

ylen

e (µ

l l-1

)

Months in Storage

Control@-1.1°C 1-MCP@-1.1°C 1-MCP@1.1°C

Solid line = Internal Ethylene Dashed line = Ethylene Production

Influence of Storage Temperature and SmartFresh Treatment on Ethylene in Anjou Pears During Storage

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8 Frui

t Firm

ness

(N) a

fter 7

d @

20C

Months in Storage

Control@-1 1°C 1-MCP@-1 1°C 1-MCP@1 1°C

Effect of SmartFresh and Storage Temperature on Recovery of Ripening Capacity (7d) in Anjou Pears

0

2

4

6

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10

12

14

0

10

20

30

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50

60

70

1 2 3 4 5 6 7 8

Firm

ness

(lbs

.-for

ce)

Firm

ness

(N) a

fter 7

d a

t 20

°C (N

)

Months in Storage

Control@-1.1°C 1-MCP@-1.1°C 1-MCP@1.1°C

Effect of SmartFresh and Storage Temperature on Recovery of Ripening Capacity in Late Harvested* Anjou Pears

* 59N

0

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120

0 1 2 3 4 5 6 7 8

Supe

rfic

ial S

cald

Inci

denc

e (%

)

Months in Storage

Control@-1.1°C 1-MCP@-1.1°C 1-MCP@1.1°C

Influence of Storage Temperature and SmartFresh Treatment on Superficial Scald Development in Anjou pears

Can We Achieve Extension of Storage Life AND Fruit Ripening after Harvest?

Amit Dhingra will speak to a possible solution in next session

How Does SmartFresh Affect Sensory Quality of Pears

This is experience we want our

consumers to have!

Experimental Design • Northern California (Lakeport) orchards • Three weekly harvests • Three Treatments

– 100 ppm Ethylene at 68°F for 24 hours

– 600 ppb gaseous 1-MCP at 34°F (2C) for 24h

– Control • Ripen fruit at 68°F (20C) • Evaluate objective and sensory quality when fully

ripe 3 lbs.-force (13N)

0

5

10

15

20

25

0 2 4 6 8 10 12 14 16 18 20 22

Firm

ness

(lbs

)

20C Control

24h. 100 ppm C2H4

24h. 600 ppb 1-MCP

0 2 4 6 8 10 12 14 16 18 20 22

Mid Season

0 2 4 6 8 10 12 14 16 18 20 22

Early Season Late Season

Softening of California Bartlett Pears at 68F (20C)

Sensory Profiles: Early Season

Overall intensity aroma

Apple aroma

Pear aromaGreen aroma

Fermented aroma

Firmness

Juiciness

Grittiness

Sw eet tasteTart taste

Fruity taste

0 1 2 3 4 5 6 7

20C Control24h, 100 ppm Ethylene24h, 600 ppb 1-MCP

Overall intensity aroma

Apple aroma

Pear aromaGreen aroma

Fermented aroma

Firmness

Juiciness

Grittiness

Sw eet tasteTart taste

Fruity taste

0 1 2 3 4 5 6 7

Sensory Profiles: Late Season

Overall intensity aroma

Apple aroma

Pear aromaGreen aroma

Fermented aroma

Firmness

Juiciness

Grittiness

Sw eet tasteTart taste

Fruity taste

0 1 2 3 4 5 6 7

Early Season

Overall intensity aroma

Apple aroma

Pear aromaGreen aroma

Fermented aroma

Firmness

Juiciness

Grittiness

Sw eet tasteTart taste

Fruity taste

0 1 2 3 4 5 6 7

Mid Season

20C Control24h, 100 ppm Ethylene24h, 600 ppb 1-MCP

SmartFresh Treated Bartlett Pears* Have

Better Sensory Quality Once Fully Softened

• Enhanced sweetness, juiciness and pear aroma • Minimized fermented aroma, gritty texture and tart taste

Escribano et al., 2016. Postharvest Biol. Technology Moya-Leon et al., 2006 Postharvest Biol. Technology

*California-grown fruit

• Packham pears treated with 200 ppb 1-MCP had greater sweetness and aroma than cold stored and CA stored pears after 4 and 6 months storage

Questions?

Best Practices for use of�SmartFresh on Pear Fruit1-MethylcyclopropenePotential Benefits of SmartFreshTMSlide Number 4Factors Influencing Pear Fruit �Response to SmartfreshTMDifferences in Variety Response to SmartFreshGrowing LocationsMaturity and Elevation EffectsSlide Number 9Slide Number 10Competition Between �SmartFresh and EthyleneMethodologySlide Number 13Slide Number 14Predicting an optimal [SmartFreshTM] Late Season Bartlett PearsPredicting an optimal SmartFreshTM Concentration Ability of Pear Fruit to Ripen �After SmartFresh TreatmentSlide Number 19Slide Number 20Changes in firmness during storage and post-storage shelf-life �of ‘Rocha’ pears treated with 312 ppb 1-MCPIncidence of internal browning during storage and shelf-life �of ‘Rocha’ pears treated with 312 ppb 1-MCPSlide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Can We Achieve Extension of Storage Life��AND��Fruit Ripening after Harvest?Slide Number 29Experimental Design Slide Number 31Sensory Profiles: Early Season Sensory Profiles: Late Season�SmartFresh Treated Bartlett Pears* Have Better Sensory Quality Once Fully Softened Slide Number 35