Cuvanje Grozdja- Izrael

8/10/2019 Cuvanje Grozdja- Izrael

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Post Harvest Handling of Table Grapes:

Principle and Practice

Amnon Lichter

Department of Postharvest Science

ARO The Volcani Center





Grapes

Non climacteric fruit and low respiration rate

Low ethylene production and no response to it

Softening due to changes in cell wall and water loss

During maturation sugar accumulation and acidity

declines Color changes by chlorophyll degradation

and anthocyanin synthesis



o

Cluster shapeo Cluster compactness

o

Berry size (shot)o Color

o

Size and color uniformityo Damage (mechanical, sun, pests)







Parameters for quality after storage

DecayFreshness and bloom

Desiccation of stems and pedicles

Firmness

Cracking

DiscolorationShatter





Taste: A complex trait

TSS: Brix (refractometer)

Acidity: % tartaric acid eq.

Index = TSS/Acidity (20/0.5)=40

Full color expression





I. Natural

· Fungal decay

· Water loss

· Senescence

II. Treatment induced:

· Bleaching (SO2)

· Condensation

· Low humidity (desiccation)

Factors which affect quality



· Acceptable thermal entry point: 26 C

· Forced air cooling with humidity control

· Optimal temperature: -0.5 C 0.5 C

· Minimal temperature: -3

C

· Optimal RH: 95%

· Minimal RH: 90%

· Minimal level of oxygen: 1%



Fungi (Major)

Bacteria (Agrobacterium)

Phytoplasma

Viruses



Unicula necator

Plasmopara viticola Phomopsis viticola

Botrytis cinerea

Rhizopus stoloni fer

Aspergil lus niger

Botrytis cinerea

Rhizopus stoloni fer Aspergil lus niger

Al ternaria alternata

Penicillium spp.

Saccharomyces spp.

Before harvest After harvest

Fungi are the major pathogens of the fruit



A severe problem in the vineyard in temperate zones

Requires free water/high humidity to establish infection

(minimum of 12 hr of free water)

The major cause of postharvest losses

Botrytis cinerea – Gray Mold







Typical to warm climate

White mycelia- black spores

Water soaked decay

Wound infection

Does not occur after cold storage

practice

Avoid insect damage

Forced air cooling

Rhizopus stolonifer –

Black Mold



Rhizopus stolonifer



Aspergillus niger



Direct or stem-end penetrationSlow development during cold storage

Dry dark and sunken tissue

Can cause berries to shatter

Altrnaria alternata



Pencillium spp.



The cuticle as a physical barrier

Inhibitory substances: preformed phenols

Induced phytoalexins (Resveratrol)

Biochemical control (PR proteins, chitinases)

Defense lines include:



ab

a

abcd

abcdabcd

abcd

cdd

bcd

abcd

abcd

d

0

10

20

30

40

Control Teldor Polar Ohaio Mitos Switch

%

D e c

a y

Early

Late

Late versus early application of fungicides



A: Decay after storage

*

0

50

100

150

200

Control Ethanol SO2

D e c a y ( N o

. k g - 1 )

B: Fungal counts

*

0

250

500

750

1000

1250

Control Ethanol SO2

C F U ( N

o . g r - 1 )

* C : C o n t

r o l

D : E

t h a n o l

E : S O 2

SO2

SO2

C

E



Control Ethanol

45 d

MA+EtOHMA

45 d

+3

c

b

a

c

b

a

b

0

10

20

30

40

P E 0 . 2

P E 0

. 2 + S

O 2

P E 0 . 2 +

E t O H P E

P E +

E t O H

N P - L

N P - L +

E t O H

D e c a y ( %

)

Specific liners with control of excess RH



Means to prevent disease development

Fungicides / Insecticides

Proper postharvest handling

Timely distribution



0

2

4

6

8

10

12

14

16

18

20

0 2 4 6 8 10 12

T in Box

T in Liner



0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6 8 9 10 11 13 14 15

Growers

D e c a y

e d B e r r i e s / B u

n c h

30 h 6 h

Two weeks in storage



Cold storage



4.5 month storage of RedGlobe 2005 with VL4 pads

0

10

20

30

40

50

60

70

PE PE HDPE HDPE

Room 9 Room 10

H e l t h y b u n c h e s ( % )

-0.16ºC +0.84ºC

HDPE PE



oApplied from paper pads containing the salt

osodium metabisulfite

o

Registered for postharvest use in the USA <(10 ppm)oSlow release depends on low temperature and

controlled humidity

oVery efficient against gray mold, if properly applied

oMaintains quality for up to 3 month

oReduces stem browning by partial bleaching

Sulfur Dioxide (SO2)

Na2S2O5+H2O

SO2



H iti it t SO ll i



Hypersensitivity to SO2 – allergic response

Damage to berries – bleaching and cracking

Undesired aftertaste

Strict management during storage

(temperature and humidity)

G id li F E f ‘S i ’ T bl G



Guidelines For Export of ‘Superior’ Table Grapes

Method A (South Africa):

The clusters are packaged in perforated PE bags

Every corrugated cartoon is lined with a non-perforated polyethylene coating(0.03 mm thick).

Corrugated paper is placed below and above the clusters for control of excess

humidity

Dual release SO2 paper is placed above the upper paper

The polyethylene lining is closed by folding the wide

margins inwards, above the chemical paper

Forced air cooling is applied for 12 to 24 h

Method B:

As above without the polyethylene lining

Forced air cooling is applied for 3 to 4 h

The pallet is wrapped with a stretch sheet (shrink)



Internal plains

Growing regions and methods



Under colored shade nets



Under plastic house in the desert





Y-shaped support system



Testing TSS before harvest (>15%) and labeling the clusters

U i h li d ti f th b t b i ’ lit



Using sharp clippers and sorting for the best berries’ quality.

Berries temperature should not exceed 26°C





Keeping the boxes in shade till transporting to the packinghouse



Protecting from direct sun

d d ‘ ’ k h f



Air conditioned ‘Home’ packinghouse for export



Ventilated ‘Carry’ bags with ziplock







Forced air cooling to reduce field heat to around 0°C for 2-6 h (for unbagged bunches)

or 12-24 h (for bagged bunches)



Optimal temperature storage -0.5°C ± 0.5°C (not below -3°C) + RH 95%, but not below

90%



Palletizing and wrapping in shrink for SO2 application





Storage facility for local markets



From the packinghouse to the port in a refrigerated truck at 0°C

Export by sea transport to Europe



Export by sea transport to Europe

Export by sea transport to Europe: inside a cooling room in the ship (0°C)



Export by sea transport to Europe: inside a cooling room in the ship (0 C)



Shed house for local market



Shed house for local market



Local market cartons with ‘Red Globe’ grapes







Pallets registered before local storage in plastic crates





Black Finger – A Volcani Seedless mid-late season

fair taste

Midnight Beauty – Seedless mid season

fair taste



Red Globe after 2 month storage – Seeded late season fair taste



Flame – Seedless early season good taste Red Superior (Sugar 14) – Seedless mid seasonfair taste





Superior – Seedless mid season fair taste Zainy – local seeded late fair taste



Autumn Royal – Seedless late fair taste Muscat Hamburgi – Seeded excellent taste



Review of the alternative methods for treatment of table grapes during storage

including the ethanol treatments

Documents

Cuvanje Grozdja- Izrael