Lecture 2 - Causes of post harvest losses.pptx

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1. 2. Causes of post-harvest losses Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

2. POST HARVEST LOSSES F & V – highly perishable commodities Wide gap between production and availability – PHL LOSS is any change in availability, wholesomeness, quality, quantity or merely a loss in market value PHL – occurring between harvest and consumption Occur between the period of separation of healthy commodity from parent plant till it reaches the consumer Can happen anywhere in the chain of harvesting, packaging, storage, transport and marketing Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

3. Nature of losses Weight loss & shrinkage – leafy veg, potato – due to transpiration, resulting in water loss Colour – cauliflower – due to high temp Texture – soft (tomato) / brittle (okra) Toughening – Beans Taste – unpleasant Bruising – due to defective management Rotting – pest & disease Sprouting – Potato/ onion – improper storage Greening – Potato – due to light in storage Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

4. Based on spoilage, commodities are classified into perishable and durable Perishable ( eg. Horticultural produce) Durable / non perishable (cereal, pulses) High moisture content (50 – 90%) 10 – 15% Large unit size (5 – 10 kg or more) 1 g or less High respiration & heat generation Low Soft & easily damageable texture Relatively thin skin/peel Inherent short shelf life Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

5. Causes of postharvest losses Mechanical or physical Internal/ physiological Biological Combination of 1, 2 & 3 Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

6. 1. Physical losses Losses due to injury on product surface Due to poor handling/ transportation/ unsuitable containers/ improper packaging – bruising, distortion Surface injuries – act as entry point of micro organism More gaseous exchange occur from injured portion resulting in water loss Different types of physical injuries Abrasion Compression Impact Punctures Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

7. Abrasion – individual fruits rub each other and against hard surface of container resulting in abrasion Nets, cushioning materials, thermoformed trays – to prevent abrasion 2. Compression – due to packaging more fruits in small container or due to higher stacking than design strength of a container Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

8. Cushioning materials : Physiologically inactive Fiberboard divider Fruit foam nets Moulded pulp trays Honey comb partitions

9. 3. Impact – dropping of containers during careless loading & transporting 4. Punctures – due to sharp plant part (pedicel of brinjal pucturing soft fruit portion) Control Careful handling Removal of injured fruits Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

10. 2. Physiological losses Harvested produce are living systems that age Respiration & transpiration – alive after harvest & continue physiological activities No source to replace the loss by these processes – weight loss Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

11. Physiological losses 1. Respiration – keeps plant alive and perishability is proportional to respiration (utilization of reserve food to release energy) Sugar/ starch + oxygen CO 2 + Water + Energy 2. Transpiration – occurs due to difference in moisture level between commodity and storage atmosphere Environmental factors affect this 3. Enzymes – due to action of enzymes 4. Ethylene production – increase in ethylene gas production results in wilting, shriveling and softening of harvested produce Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

12. Biological losses Macro agents (rodents & birds) Micro agents ( mould , bacteria and virus) Greatest loss of F & V in storage – rot – caused mainly by mould and bacteria Biological losses due to micro organism – result in disease Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

13. Control of postharvest diseases can be done by Prevention – using disease free material, resistant varieties Eradiation – trimming out diseased material, hot water treatment Control of environment – temp. control Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

14. Post harvest losses in field Mechanical damage by harvesting implements Rough handling after harvest Excess exposure to sunshine Improper control of pest and disease Harvesting at improper maturity stage Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore

15. Post harvest losses in transportation Use of unsuitable containers Overloading of fruits and vegetables Irresponsible driving, rough roads Heat accumulation or poor ventilation in vehicle Absence of refrigerated vehicle Post harvest losses in storage & market Damage by pests, disease and rodents Inadequate cold storage facilities Dr. Karishma Sebastian, Asst. Professor, SAS, KITS, Coimbatore