inoue -color changes fruit-ripening conditioning...

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Kentaro InoueUniversity of California, Davis

[email protected] 15th, 2010

Fruit ripeningColor change and Conditioning

1. Fruit development – Definition of maturation and ripening

2. Importance of color

3. Conditioning for ripening- Some climacteric fruits as examples

Fruit ripeningColor change and Conditioning

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Stages of fruit development1. Fruit development

MaturationThe stage of development leading to the attainment

of physiological or horticultural maturity

• Physiological maturity:– The stage of development when a plant or plant

part will continue ontogeny even if detached

• Horticultural maturity:– The stage of development when a plant or plant

part possesses the prerequisites for utilization by consumers for a particular purpose

1. Fruit development

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Ripening:The composite of the processes:- Occurring from the latter stages of growth

and development through the early stages of senescence

- Resulting in characteristic aesthetic and/or food quality, as evidenced by changes in composition, color, texture, orother sensory attributes

1. Fruit development

Compositional changes accompanying fruit ripening1. Fruit development

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Maturity and ripeness stages of Maturity and ripeness stages of cherry tomatoescherry tomatoes

1 2 3 4 5 6 >6 1 2 3 4 5 6 >6

Optimal harvest stages 1. Fruit development

For us..

For plants..

- Cosmetic value- Indicator of ripening

- Nutritional value

- Red/orange etc - Attract seed dispersers- Protect tissues from oxidative stress

= Antioxidant

- Green - light capture (photosynthesis)

Importance of “Color”


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http://www.recipezaar.com/bb/viewtopic.zsp?t=254626

Anthocyanins

antioxidants

O+

O-Glc

OH

OH

OH

OH

OCH3

O

O

O

O

R1

O

R2

O

provitamin A

antioxidants


Carotenoids

Vacuole

chromoplasts

nucleusmitochondria

O+

O-Glc

OH

OH

OH

OH

OCH3O

O

O

O

R1

O

R2

O

“Phenylpropanoids*” “Isoprenoids (terpenoids*)”

cell

Plasma membraneCell wall

*Cf. Dr. Zakharov’s lecture 2. Importance of color

Anthocyanins Carotenoids

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O

O

O

O

R1

O

R2

O

http://www.hormel.com/images/glossary/m/mango_champagne.jpg

chromoplast

lycopene

cis-β-carotene

Esters of cis-violaxanthin

“crystaline structure”

“globules”

Electron microgram


N

N

N

CH3O OH O

HH

Mg2+

N

R1

OO

R2

carotenoids“Non-photosynthetic”

chromoplast

chloroplast

“Photosynthetic”carotenoids

chlorophylls

OH

OH

O

O

O

O

R1

O

R2

O

Color Break


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Thylakoidstacking

Carotenoid-containing globules

Electron microgram by Thomson ‘66


Group 1: Nonclimacteric fruits:Fruits that are not capable of continuing their ripening process once removed from the plant

WatermelonPineappleLongan

TamarilloPepper (bell)Lime

StrawberryOrangeLemon

RaspberryMuskmelon*Grapefruit

RambutanMandarinGrape

Prickly pearLycheeCherry

PomegranateLoquatBlackberry

*Some muskmelon varieties are climacteric, but are best when harvested partially- or fully-ripe.

3. Conditioning for ripening

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Maturity and ripeness stages of cherries

Optimal harvest stage


Strawberries must be picked fully-ripe

b/c they do not continue to ripen (improve in flavor) after harvest

Maturity and ripeness stages of strawberries

Optimal harvest stage


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Group 2: Climacteric Fruits:Fruits that can be harvested at physiological maturityand ripened off the plant

Pepper (chili)Kiwifruit

TomatoPearGuava

SapotePeachCherimoya

SapodillaPassion fruitBanana

QuincePapayaAvocado

PlumNectarineApricot

PersimmonMangoApple

Except avocado, banana, and pear, these fruits attain best flavor if ripened on the plant


Maturity and ripeness stages of apricots

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22

33 55

44 Optimal harvest stages for good flavor


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Optimal conditions for ripening of climacteric fruits

Ripening roomsTemperature: 15 to 25ºC (59 to 77ºF)Relative humidity: 85-95%

Air circulation (more uniform temperature and ethylene concentration)

Ventilation (introduction of fresh air to keep carbon dioxide below 1%)

Treatment with ethylene100 ppm ethylene in air for 1-3 days, depending on maturity stage at harvest


Ripening rooms

Temperature and relative humidity management is the most important factor affecting ripening rate & uniformity


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Ripening rooms

Ethylene generator

Forced-air (pressure) ripening room


18-20ºC / 65-68ºF24-72Tomato

20-25ºC / 68-77ºF24-48Pear

20-25ºC / 68-77ºF24-48Mango

12-25ºC / 54-77ºF12-24Kiwifruit

14-18ºC / 58-65ºF24-48Banana

15-20ºC / 59-68ºF8-48Avocado

Range of ripening temperatures2

Exposure time (hours)1

to 100ppm ethylene Fruit

1 Shorter duration for more mature fruit2 Faster ripening rate at higher temperatures

Ripening conditions for some commonly-ripened fruit


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Current recommendations for avocado ripening

Adequate air flow to keep CO2 below 1%

Carbon dioxide level:

8-48 hr, depending on maturity stage

Duration:

10-100ppmEthylene concentration:

90-95%Relative humidity:

15.5-20°C (60-68°F)Temperature:


Effect of harvest date (maturity) on the time to ripen for ‘Hass’ avocado

5.18.2June 5

7.110.1April 10

8.812.8Feb. 6

10.813.9Dec. 8

Treated*ControlHarvest date

Days to ripen at 20°C (68°F)

* Fruit treated with 1000ppm propylene, an ethylene analogue


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Ethylene (C2H4) is required to induce banana ripening


Ethylene (C2H4) induces ripening of various banana and plantain cultivars


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Ripening conditions for banana

Adequate air exchange to prevent accumulation of CO2 above 1%

Carbon dioxide:

24-48 hours, depending on maturity stage

Duration of

exposure to ethylene:

100 ppmEthylene concentration:


14-18°C (58-65°F)Fruit temperature:


Effect of temperature during ripening on banana quality attributes


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=


Note the 5-fold increase in respiration rate (carbon dioxide production) as banana ripens from stage 2 to stage 4.

mg

kg


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Carbon dioxide reduces efficacy of ethylene in inducing banana fruit ripening


80% RH

Low relative humidity (RH) accelerates water loss and appearance of physical damage symptoms on banana


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Mango maturity indices• Fruit shape (fullness of the shoulders)

• Skin ground color change from dark-green to light-green to yellow (depending on cultivar)

• Flesh color change from green to yellow to orange

• Increase in total solids (dry weight)

• Increase in soluble solids (mainly sugars) and decrease in acidity


Mango maturity and ripeness stages

*

**

*

*Minimum stage for harvestManilla

Kent


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Ripening conditions for mango

<1%Carbon dioxide:

24-48 hours, depending on maturity stage (flesh firmness)

Duration of

exposure to ethylene:

100 ppmEthylene concentration:


20 to 22°C (68-72°F)Fruit temperature:



Mango ripeness vs. flesh firmness

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1

2

3

4

Maturity and ripeness stages of Nectarine

Immature

Mature-green

Partially-ripe

Ripe

1

2

3

4


Ethylene effects on stone fruit ripening at 20°C (68°F) as indicated by flesh firmness (means + standard deviation)

1.8±1.02.2±0.61.8±0.4With 20ppm ethylene

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3.7±2.12.8±1.22.3±1.0W/O added ethylene

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6.1±1.915.3±1.511.6±2.1At harvest0

PlumPeachNectarineTreatmentDays

Flesh Firmness (pounds-force)


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Delayed cooling = conditioning = ripening of peaches to reduce internal breakdown

0ºC 20 Days 20ºC 48 Hours + 5ºC 20 DaysFrom: Carlos Crisosto

(43% Mealy) (0% Mealy)

(100% Mealy)

5ºC 20 Days


SmartfreshTM TechnologyOn July 17, 2002, USEPA approved registration of SmartfreshTM

technology and established an exemption from tolerance for its active

ingredient: 1-methylcyclopropene (1-MCP) for the following fruits:

apple, apricot, avocado, kiwifruit, mango, melon, nectarine, papaya, peach, pear, persimmon, plum, tomato.

Approval in other countries and for more commodities has occurred since 2002.

Responses of 1-MCP-treated fruits to ethylene depends on 1-

MCP concentration used (100 to 1000 ppb) and elapsed time

since the treatment.


inoue -color changes fruit-ripening conditioning...

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