Next

1
Storage of Grapes
Next
2
Introduction
Grapes are cultivated in many countries of the
world. India produces only about 2.77 per cent of
the total world production. However, in
productivity India stood first with 23.50 tonnes
/ha. Grape is one of the most perishable fruits
and during the process of distribution and
marketing, substantial losses are incurred which
ranges from a slight loss of quality to total
spoilage. Post-harvest losses may occur at any
point in the marketing process, from the initial
harvest through assembling and distribution to
the final consumer. The causes of losses are
many physical damage during handling and
transport, physiological decay, water loss, or
sometimes due to glut in the market and there are
no buyer. After harvesting grapes are to be kept
in shade. Cooling is necessary to reduce the rate
of fruit respiration, retard the development of
decay and most importantly to minimize water loss
from the fruit. In order to control decay of
table grapes, fumigation with sulfur dioxide is a
common practice. However, it is important to
consider that grapes treated with sulfur dioxide
will necessarily call for storage under low
temperatures.
3
Post harvest diseases of Grapes

• Anthracnose/ Bird eye spot Elsinoe ampelina
• Botrytis Bunch Rot or Gray Mold of Grape
  Botrytis cinerea
• Blue mould rot Penicillium digitatum
• Stalk end rot Aspergillus niger
• Rhizopus rot Rhizopus nigricans

4
http//agritech.tnau.ac.in/crop_protection/crop_pr
ot_crop20diseases_postharvest_grapes.html
1. Anthracnose/ Bird eye spot Elsinoe ampelina
The disease mainly spread due to splashing of
rain water. Initially small, reddish circular
spots develop on berries which eventually develop
in the lesions. A pinkish mass of fungal spores
(conidia) exudes from these structures during
prolonged wet weather condition
2. Botrytis Bunch Rot or Gray Mold of Grape
Botrytis cinerea Infected berries first appear
soft and watery. Berries of white cultivars
become brown and shriveled, while purple
cultivars develop a reddish color.Healthy berries
touching infected berries will become infected.
Rotted berries generally shrivel and drop to the
ground as hard mummies .
Source http//agritech.tnau.ac.in/crop_protection
/crop_prot_crop20diseases_postharvest_grapes.html
5
3. Blue mould rot Penicillium digitatum
Scanty growth - white  and turn bluish green are
seen. Decay the berries Infected tissues become
soft and watery and emits a moudly flavour
4. Stalk end rot Aspergillus niger Brown rot at
stalk end is start point of attack the pathogen.
Rotting begins as a small, circular to oval,
water soaked spots are  brown in colour. Infected
berries are soft and emit bad odour
5. Rhizopus rot Rhizopus nigricans Round
irregular, light brown and water soaked lesion
appear on fruits. Decaying fruits emits
fermented, moudly smell.
Source http//agritech.tnau.ac.in/crop_protection
/crop_prot_crop20diseases_postharvest_grapes.html
6
Physiological Disorders of Grapes
1. Internal browning Its a physiological
problem that develops during cold storage .
2. Browning Bleaching of Berries browning is
mainly caused when berries are removed from the
cold storage while bleaching occurs when sulfur
dioxide penetrates the wound severely bleach
the surrounding tissues. It affects its
marketability.
3. Freezing or low temperature injury Berries
develop freezing injuries during storage hence it
is advised to maintain the optimum temperature of
storage
Sourcehttpwww.rootsofpeace.orgdocumentsPostharves
t_Technology_and_Methods_for_Grapes_and_Raisins-de
veloped_by_UCD_for_ROP-2005.pdf
7
Physiological Disorders of Grapes
--cont-- Postharvest berry drop This is due to
weak pedicel attachment to the berries. This is
common in Anab-e-Shahi, Cheema Sahebi and Beauty
Seedless. Spraying of NAA (50 ppm), a week prior
to harvesting can minimize the post-harvest berry
drop.   Uneven ripening Presence of green
berries in a ripe bunch of coloured grapes is
called uneven ripening. It is varietal character
and a problem in Bangalore Blue, Bangalore
Purple, Beauty Seedless and Gulabi grapes. Within
a variety this problem varies from
bunch-to-bunch. Generally inadequate leaf area
and non-availability of reserves to a developing
bunch is the reason. Cultural practices like
cluster thinning, girdling and use of growth
regulators can reduce uneven ripening.
Application of Ethephon (250 ppm) at colourbreak
stage is recommended to reduce the problem.
8

• Packaging
• For local market, grapes are packed in bamboo
  strip baskets using newspaper and grape leaves as
  cushioning material. One basket contains 6kg of
  grapes.
• For distant markets (within the country),
  wood or corrugated cardboard boxes are used for
  packing. Old newspapers, hay and paper shreds are
  used as cushioning material. The size if packing
  is 6 or 8kg in wood boxes, and 2 or 4kg in
  cardboard boxes.
• Grapes for overseas markets are packed in
  five-ply corrugated fibre board boxes, printed
  and labeled attractively. The standard dimensions
  of the carton are 50 cm. x 30 cm. x 12 cm. to
  accommodate 5 kg grapes.
• For the European market, bunches of grapes
  of approx. 300 to 700 gms. are packed in food
  grade plastic pouches. They are then wrapped in
  polythene sheet along with grape guard and
  tissue paper.
• Grapes are packed in ventilated cardboard
  boxes using dual release sulphur dioxide
  releasing pads (grape guard) as an in packing
  material to check the postharvest diseases
  during transit and storage

9
Recommended storage conditions
Optimum Temperature 0C Optimum Relative
Humidity 92-96 Exposure to temperatures above
0 C (32 F) can greatly increase shatter and
decay, especially in tightly packed clusters.
The shelf life of grapes is only one week at
room temperature. The storage life of grapes can
be increased by employing suitable means to
reduce desiccation, decay due to growth of fungi
e.g. Botrytis, Cladosporium, Alternaria etc. and
bio-chemical deterioration. Harvesting the
over-ripe grapes during hot hours of the day,
careless handling to cause bruises and injuries
to the berries at harvest and packing stage can
reduce the storage life of grapes. Under optimum
conditions of storage, the maximum storage life
of Anab-e-Shahi variety is 40 days, Muscat 45
days, Thompson Seedless 30-60 days etc
10
Methods to increase the shelf life of Grapes
Type of treatment Period of Application Effect
Spraying of fungicides- Captan (0.2), aureofungin (500 ppm.), DCNA (2,6-dicholoro-4-nitroaniline)-0.2 3-4 days before harvest Reduce decay of berries in storage.
Application of growth retardants- NAA (500 ppm.), kinetin (50 ppm.) Before harvest Reduce berry drop during storage.
Spraying of growth retardants- B-9 (2000 ppm.), CCC (2000 ppm.), Alar (500 ppm.), maleic hydrazide (500 ppm.), phosphon-D (500 ppm.) At harvest or berry softening stage Retain the freshness of grapes for a longer period.
Sraying with Calcium nitrate (1) Ten days before harvest Reduce the physiological loss in weight.
Source nhb.org
11
Response to CA Storage Not currently used at
commercial scale Response to Ethylene
Stimulation of Botrytis cinerea (gray mold)
growth can occur on berries and stems in the
presence of ethylene. Production from American
grapes is lt 0.1 µL kg-1 h-1.
12
Rates of Respiration Production
Temperature 0C 4to 5C 10C 15 to 16C 20 to 21C 25 to 27C
mg CO2 kg-1 h-1 3 5 8 16 33 39
To get ml kg-1 h-1, divide the mg kg-1 h-1 rate
by 2.0 at 0 C (32 F), 1.9 at 10 C (50 F), and
1.8 at 20 C (68 F). To calculate heat
production, multiply mg kg-1 h-1 by 220 to get
BTU per ton per day or by 61 to get kcal per
metric ton per day.
13

• Let us sum up
• India produces only 2.77 of the total world
  production but in productivity India stood first
  with 23.50 tonnes/ha. Grape is one of the most
  perishable non-climacteric fruits. The causes of
  postharvest losses are many physical damage
  during handling and transport, physiological
  decay, water loss, or sometimes due to glut in
  the market and there are no buyer. After
  harvesting grapes are to be kept in shade.
• Cooling is necessary to reduce the rate of fruit
  respiration, retard the development of decay and
  most importantly to minimize water loss from the
  fruit. In order to control decay of table grapes,
  fumigation with sulfur dioxide is a common
  practice along with storage under low
  temperatures.
• For local market, grapes are packed in bamboo
  strip baskets (6 Kg cap.) using newspaper and
  grape leaves as cushioning material. One basket
  contains 6kg of grapes. For distant markets and
  exports, grapes are packed in five-ply corrugated
  fibre board boxes (50 cm. x 30 cm. x 12 cm) with
  cap. of 5 kg fruits.

14

• Let us sum up cont--
• Optimum storage temperature is 0C and RH 92-96.
  Exposure to temperatures above 0 C (32 F) can
  greatly increase shatter and decay, especially in
  tightly packed clusters. Shelf life of grapes is
  only one week at room temperature.
• The storage life of grapes can be increased by
  employing suitable means to reduce desiccation,
  decay due to growth of fungi e.g. Botrytis,
  Cladosporium, Alternaria etc. and bio-chemical
  deterioration. Under optimum conditions of
  storage, the maximum storage life of Anab-e-Shahi
  variety is 40 days, Muscat 45 days, Thompson
  Seedless 30-60 days etc.