🌸 Post-Harvest Technology and Cold Chain

This lesson builds core elective concepts in BSc Agriculture with practical applications and exam-oriented clarity.

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Post-Harvest Technology and Cold Chain

Post-Harvest Losses in India

India loses 25–40% of fruits and vegetables between harvest and consumption due to inadequate handling, storage, and transportation infrastructure. This translates to an annual loss valued at over ₹90,000 crore.

Post-Harvest Operations

1. Pre-Cooling

Rapid removal of field heat immediately after harvest to slow respiration and senescence.

Method	Cooling Rate	Suitable Crops
Room cooling	Slow (hours)	Citrus, root vegetables
Forced-air cooling	Medium (1–6 hrs)	Berries, stone fruits
Hydrocooling	Fast (minutes)	Cherries, celery, carrots
Vacuum cooling	Very fast (minutes)	Leafy vegetables, lettuce

2. Sorting, Grading, and Packaging

• Sorting: Remove damaged, diseased, and immature produce
• Grading: Size-based (mechanical graders) and color-based (electronic sorters)
• Packaging: CFB boxes, plastic crates, cushioned trays — prevent bruising during transit

3. Storage Technologies

• Cold storage: 0–12°C depending on commodity; RH 85–95%
• Controlled Atmosphere (CA): Reduced O₂ (2–5%), elevated CO₂ (2–5%); extends apple storage to 8–10 months
• Modified Atmosphere Packaging (MAP): Sealed film packs with specific gas permeability
• Evaporative cool chamber (zero energy): Low-cost structure using wet sand/brick; reduces temperature by 10–15°C

Optimal Storage Conditions

Crop	Temperature (°C)	RH (%)	Storage Life
Mango	12–13	85–90	2–3 weeks
Banana	13–14	90–95	2–4 weeks
Apple	0–1	90–95	3–8 months
Tomato (mature green)	12–15	85–90	2–4 weeks
Onion	0–2	65–70	6–8 months

Cold Chain Infrastructure

A cold chain is an unbroken series of refrigerated production, storage, and distribution activities that maintain a consistent low-temperature range.

Components

1. Pack house: Sorting, grading, pre-cooling at farm gate
2. Reefer vehicles: Refrigerated trucks/vans for transport
3. Distribution hub: Cold storage at wholesale market
4. Retail cold display: Refrigerated cabinets at retail
5. Last-mile delivery: Insulated boxes for home delivery

Government Support

• PM Kisan SAMPADA: Integrated cold chain and value addition scheme
• MIDH: 35–50% subsidy for cold storage and pack house
• NABARD: Term loans at concessional rates for cold chain projects

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Summary Cheat Sheet

Topic	Key takeaway
Main focus	Post-Harvest Technology and Cold Chain.
Section context	Revise this lesson with the rest of Hi-Tech Horticulture for stronger conceptual continuity.