HORTICULTURE

1. HYPOBARIC STORAGE AND IRRADIATION IN
FRUITS AND VEGETABLES PRESERVATION

2. HYPOBARIC STORAGE (LOW PRESSURE
STORAGE)
 Hypobaric Storage refers to the storage of fruits and vegetables
under reduced atmospheric pressure.
 The storage life of many fruits and vegetables can be extended
by reduced pressure under refrigeration due to low respiration
rate and evacuation of ethylene.
 This is form of Controlled Atmospheric storage (CAS)
 This was first proposed by Burg and Burgl in 1966.

3.  Fruits were held at about 0.2 to 0.5 atmospheric pressure at 15 to
24°Celsius.
 There was reduction in level of ethylene in the fruits and the
oxygen in the chamber.
 It was found that
i. Reduced oxygen supply slows down respiration and production
of ethylene.
ii. Flushing of ethylene removed from the fruits out of the storage.
iii. Removal of other volatiles produced from fruits and vegetables.

4. Applications:
 In apple such as carbon dioxide, acetaldehyde, acetic acid esters
and a- fernescene, 6-methyl-5-hepten-2-one (MHO), accounts
for the results from hypobaric storage.
 Atmospheric pressure is reduced to 0.10 from normal pressure.
 Oxygen concentration is lowered from 21% to 2.1%.
 Ethylene level is reduced to 0.01ppm which does not stimulate
ripening.
 In banana storage life is doubled at 0.55atm and again doubled
at 0.33atm.

5. Comparative storage life (In days) of produce stored
in Refrigeration and under Hypobaric conditions
COMMODITY COLD STORAGE HYPOBARRIC STORAGE
PINE-APPLE 9-12 40
GRAPE 30-40 90-120
STRAWBERRY 5-7 21-28
BANANA 10-14 90-150
APPLE 60-90 300
PEAR 45-60 300
CUCUMBER 10-14 41
BEAN 10-13 30
ONION(green) 2-3 15
TOMATO(mature green) 14-21 60-100
TOMATO(breaker) 10-12 28-42
LETTUCE 14 40-50

7. IRRADIATION IN FRUITS AND
VEGETABLES PRESERVATION
 It is exposure of fruits and vegetables to ionizing radiations from
radioactive sources under the controlled conditions to disinfect,
to sterilize and preserve the produce.
 It is also called as cold pasteurization.
 SI unit of irradiation is Gray (J/Kg)
 These radiations differ in wavelength, frequency, penetrating
power.

8. SOURCES OF IRRADIATION
Gamma rays from radioisotopes such as cobalt-60 or
cesium-137.
X-rays from machine sources operated at or below
energy level of 5Mev.
Electrons generated from sources operated at or below
an energy level of 10Mev.

9. ADVANTAGES
It is a physical, non additive process causing minimal
changes in fruits.
Helps to keep the chemical burden in fruits at low
level.
It helps to preserve the fruits in natural form.
Increase level of quality assurance.
Nutrition value of fruits is preserved.

10. APPLICATION OF IRRADIATION AT
DIFFERENT DOSE LEVELS
 Low dose:
1. Sprout inhibition in bulbs and tubers (0.03-0.15kGy)
2. Delay in fruit ripening (0.25-0.75kGy)
3. Insect disinfestation (1-10kGy)
 Medium dose:
1. Reduction of pathogens (2.5-10kGy)
 High dose:
1. Extends the shelf life of fruits and vegetables (5-7kGy)

11. APPLICATION BASED ON EFFECT OF
TREATMENT
 Radappertization(25-45kGy): This applies dose of ionizing
radiation sufficient to bring about commercial sterility in
product.
 Radicidation(2-8kGy): A dose of ionizing radiation sufficient to
reduce number specific non spore forming bacteria.
 Radurization(0.4-10kGy): A dose of ionizing radiation sufficient
to enhance keeping quality at refrigerated temperature by
reducing viable specific spoilage micro organisms.

12. Sprout inhibition in tuber crops
A very low concentration of 0.15kGy or less inhibits
sprouting of products such as potatoes, onion, garlic,
yam etc.
Irradiation inhibits the division in meristematic tissue
there by inhibits the sprouts.
Irradiation of potatoes combined with refrigeration at
15°C extends storage period about 6 months.

13. Shelf life extension in fruits
 Irradiation kills micro organisms that cause spoilage and
deterioration of fruits.
 A dose of 5kGy or less to fresh strawberries , papayas mangoes
are irradiated and marketed successfully.
 A dose of 0.3-1kGy can increase shelf life of mangoes by about 1
week
 In banana it increase shelf life up to two weeks.

14. Delaying in ripening
Some temperate zone fruits like apple, pear and
apricot require >1kGy for effective inhibition of
ripening.
Inhibits ethylene production by fruits when irradiated.
Ripening of several fruits like bananas, mango,
papaya, guava delayed when treated medium dose of
radiation.

17. References:
Post Harvest Management of Horticulture Crops:- S.
Saraswathy, T.L. Preethi, S. Balasubramanyan, J.
Suresh, N. Revathy, S. Natarajan.
Text Book of Post Harvest Technology of Fruits and
Vegetables:- L.R. Verma and V.K. Joshi
Fruits and Vegetables Preservation Principles and
Practices:- R.P. Srivastava and Sanjeev Kumar

18. PRESENTED TO:
Mr. KUSHAL
ASSISTANT PROFESSOR
DEPARTMENT OF HORTICULTURE
COLLEGE OF AGRICULTURE B’GUDI
PRESENTED BY:
SANKETH ASHOK U
ID NO. UG14AGR2078
THIRD YEAR B.Sc.(AGRI)