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MANAGEMENT OF POST HARVEST LOSSES IN VEGETABLES

Presented by,Dr. M.K.Rana

PER CENT LOSSES IN VEGETABLES Total losses of vegetables in India due to inadequate post-harvest

handling, transportation and storage have been estimated 20-30%.

In some vegetables the post-harvest losses may be as high as 80-100%.

In developing countries the losses have been estimated: 16-35% for onion 20-50% for tomato 37% for cabbage 49% for cauliflower 62% for lettuce

PRIMARY LOSSES SECONDARY LOSSES

NATURE AND CAUSES OF LOSSES

PRIMARY CAUSES OF LOSS

LOSSES DUE TO MECHANICAL MEANS LOSSES DUE TO PHYSICAL MEANS LOSSES DUE TO MICROBES ATTACK LOSSES DUE TO PSYCHOLOGICAL PHOBIA 

MICROIAL ATTACK

MAJOR PATHOGENS CAUSING DECAY

FUNGIAlternariaBotrytis Diplodia Fusarium Monilinia Penicillium Phomopsis Rhizopus

BACTERIAErwinia Ceratocystis Pseudomonas

LOSSES DUE TO PHYSIOLOGICAL PROCESSES• ELONGATION OF EXISTING STRUCTURE•  TROPIC RESPONSE •  SEED GERMINATION•  TOUGHENING•  SPROUTING •  ROOTING •  GREENING•  RESPIRATION•  TRANSPIRATION•  RIPENING•  SENESCENCE

SECONDARY CAUSES OF LOSS

SOURCES OF MOISTURE LOSSStomata in leafy vegetablesCuticles in fruit vegetables Lenticels in potatoStem scars in tomatoCracks in tomato

FACTORS AFFECTING TRANSPIRATION

Stage of harvesting Time of harvesting Method of harvesting Mechanical injuries Surface to weight ratio Precooling Washing Waxing

1. Carnauba wax (from the carnauba palm tree)2. Shellac wax (from the lac beetle)3. Beeswax

Packaging material Storage temperature

LOSSES DUE TO BIOCHEMICAL PROCESSES• Synthesis or destruction of pigments  • Enzymatic changes in amino acids and protein  • Enzymatic changes in organic acids content  • Enzymatic change in pectic substances • Enzymatic carbohydrate conversion • Enzymatic change in flavour • Enzymatic changes in lipids • Maillard reactions

Fat oxidation Synthesis or destruction of pigments Enzymatic changes in amino acids and protein Enzymatic changes in organic acids content Enzymatic change in pectic substances Enzymatic carbohydrate conversion Enzymatic change in flavour Enzymatic changes in lipids Maillard reactions Fat oxidation

CONTROL OF POST HARVEST LOSSES

CULTURAL OPERATIONS HARVESTING TIME & METHOD TRANSPORTATION  ENVIRONMENTAL CONTROL PROPER STORAGE STRUCTURE

TYPES OF STORAGE

CONTROLLED ATMOSPHERE STORAGE MODIFIED ATMOSPHERE STORAGE  LOW TEMPERATURE STORAGE COLD CHAIN STORAGE

IRRADIATION (RADURIZATION) DEHYDRATION

To improve shelf life of vegetables treatments should be applied that are,

1.PRE-HARVEST TREATMENTS (MH in potato and onion and leafy greens)

PRE-COOLING CURING TRIMMING SORTING GRADING WASHING WAXING PACKAGING

Storage of potatoGrading and sorting

Packaging and storageCuring in potato

2. POST-HARVEST TREATMENT WITH CHEMICALS Treatment With Fungicides (methyl thimphanate (as

topsin m) or carbendazim or imidazole (p1-ima) or benomyl (0.1%) fungicide as pre or post harvest treatment)

Fumigation with sulfur dioxide Treatment with streptomycin (1000ppm) Reatment with acetic acid (0.2%) Treatment with boric acid (0.2%) Treatment with lactic acid (0.2%) Treatment with common salt (1%) Treatment with hot water (50oc) Use of antitranspirants (wax emulsions, kaolin and films

packaging)

Use Of Growth Promoters, (CYTOKININ, BA, KINETIN AND AUXINS LIKE 2,4-D, NAA

Delay Chlorophyll Degradation And Senescence, Ga3 Delays Ripening)

Use Of Growth Retardants, (ALAR, CCC, B9, CULTAR)

Use Of Growth Inhibitors, (MH, CIPC, IPC, MENA) Use Of Ethylene Absorbents,, (Purafillr- Alkaline Kmno4 On

A Silicate Carrier) Use Of In-package Moisture Absobents (Calcium oxide or

silica gel) Use of metabolic inhibitors, (cyclohexamide, actinomycin-d,

vitamin k5, maleic acid, ethylene oxide, carbon monoxide)

3. CULTURAL OPERATIONS THAT PROVIDE BETTER SHELF LIFE

Adopt cultural operations that ensure usual development of plant parts and avoid infection of decay causing organisms

Removal of stones and previous crop residues from the field and thorough preparation of soil

Avoid irregular supply of irrigation at late mature stage in onion, tomato, muskmelon, snapmelon, watermelon

Avoid excessive irrigation in potato and carrot

Stop irrigation at maturity in potato, sweet potato, onion and garlic.

Avoid excessive use of n fertilizers Remove weeds that harbour insect-pest and

diseases, not in muskmelon Avoid contact of fruits with moist soil by

providing support to vines Blanching in cauliflower offers curds that

have longer shelf life.

THANK YOU