Post-Harvest Handling and Packing

Ninety per cent of packhouse quality problems are really field-to-packhouse transport problems. The workflow below is what a commercial banana packing line does, scaled down to something a small operator can run with buckets and a shade house.

The sequence#

harvest → field transport → de-handing → washing/defluxing → fungicide dip
        → draining → grading → packing → cooling → dispatch

Every step has a maximum time and a single failure mode. Both matter.

Step 1 — Receive and de-hand#

Parameter	Target
Max time from cut to de-hand	2–4 hours
Area	Shaded, clean, with drainage
Tool	Sharp de-handing knife or powered de-hander
Cut position	Flush at the crown, leaving 3–5 mm of stalk — no gouging

Technique: cut the hands off the bunch from the bottom up (or with a powered de-hander, in one pass), holding the hand so the crown never strikes a hard surface. Lay hands crown-down on a padded surface or directly into the washing tank.

Failure mode: a ragged crown cut. Crown rot organisms colonise jagged tissue far faster than clean cuts.

Step 2 — Wash and deflux#

Defluxing: soak or spray hands for 2–4 minutes in clean water at 30–35 °C so the latex runs rather than setting. Some operations use a brief warm-water bath with a surfactant.
Change the water when it becomes visibly milky — dirty water re-deposits latex and fungi onto fresh cuts.
Follow with a clean water rinse.
Keep drainboards and rollers padded; bruising at this stage appears only after ripening.

Step 3 — Fungicide / crown-rot treatment#

Crown rot (Colletotrichum gloeosporioides, C. musae, Lasiodiplodia and others) is the single most common packout loss.

Approach	Typical practice
Post-harvest fungicide dip	Registered product at label rate, crown contact, per label contact time. Follow the label — it is a legal document and residues are monitored
Hot water	Brief dips around 50–55 °C for a short period reduce fungal load and latex — validate against your cultivar first, as scald risk is real
Biological	Trichoderma-based or other registered biocontrol products — used in organic and residue-sensitive supply chains
Nothing	Accept higher crown-rot losses — acceptable only for immediate local sales

Always check maximum residue levels (MRLs) and pre-harvest intervals with your buyer before selecting a product. Export markets reject on residue, not just on rot.

Step 4 — Drain, cool and grade#

Draining#

Hands must be surface-dry before packing — trapped moisture in a box creates an anaerobic microclimate and accelerates decay. Drain on an incline for 5–10 minutes or use a fan-assisted drain.

Hydrocooling / forced-air cooling#

Method	Mechanism	Time to pulp temperature	Notes
Hydrocooling	Chilled water spray or immersion	15–30 min	Fastest; requires good drainage and hygienic water
Forced-air cooling	Cold air pulled through the pallet	1–3 h	Most common for packed boxes
Room cooling	Passive cold store	6–12 h	Slow; acceptable only for short holds

Target: pulp temperature 13–14 °C as quickly as possible, then maintain. Never cool below 13 °C — chilling injury causes grey skin, pitting and failure to ripen evenly.

Grading#

Grade on a padded table under good light. Remove and divert:

Defect	Cause	Action
Split fingers	Over-maturity, rain after drought, rough handling	Reject or downgrade
Crowns brown/black or rotted	Slow processing, dirty water, ragged cuts	Reject
Latex staining	Drying before defluxing	Downgrade
Sunburn / heat scorch	Field exposure	Reject
Insect stings, thrips scarring	Field pest pressure	Downgrade or reject
Rubbing / transit scarring	Wind, tight packing, no propping	Downgrade
Uneven hand size, deformed fingers	Water stress at filling, poor pollination set	Segregate
Mould on crown	Post-harvest infection	Reject and record

Keep grades physically separated — one rotten crown in a box contaminates the rest.

Step 5 — Pack#

Parameter	Target
Box	Ventilated, food-grade, clean, correct specification for the buyer
Crown padding	Non-absorbent material under and between crowns
Film liner	Perforated LDPE where required — reduces moisture loss without trapping condensation
Filling	Hands aligned the same direction, crowns together, no finger pressure points
Weight	To specification, recorded per box
Label	Block, harvest date, grade, packer — traceability is not optional
Stacking	Palletised and banded; never stack boxes on fingers

Load height matters — banana boxes are strong on the corners, not the faces. Do not exceed the rated stack height.

Step 6 — Hold in the cold chain#

Parameter	Green holding	Notes
Temperature	13–14 °C	Below 13 °C = chilling injury
Relative humidity	90–95%	Lower = shrivel and weight loss
Airflow	Gentle, continuous	Ethylene must be removed or it triggers premature ripening
Ethylene	Keep below 0.1 ppm in store	Ripening is autocatalytic — one fruit starting triggers the rest
Duration	Depends on cultivar and transit; often 1–3 weeks for Cavendish	Monitor pulp temperature, not just air temperature

Never store green bananas with ripening fruit, apples, melons or any other ethylene source.

Time budget (summary)#

Step	Maximum
Cut → de-hand	2–4 h
De-hand → wash	Immediate
Wash → fungicide	Immediate
Fungicide → drain	10 min
Drain → cool	30 min
Cool to 13–14 °C pulp	1–3 h
Pack → dispatch	Per buyer schedule, unbroken cold chain

Total: fruit should be cold and packed within 4–6 hours of cutting. If your system cannot do that, your grade-out will show it.

Hygiene and food safety#

See Quality and food safety for certification requirements.

Small-scale version#

A small grower can do this with a shaded table and buckets:

Cut and carry to shade within 2 hours.
De-hand with a sharp knife onto a padded basin.
Soak 3 minutes in warm (30–35 °C) water, agitating until latex stops streaming.
Rinse in clean water.
Apply the registered crown-rot treatment if you sell on credit or ship any distance; otherwise rinse and drain well.
Drain on an incline 10 minutes.
Grade and pack into ventilated crates with crowns padded.
Move to shade or a cool room; do not stack bags of fruit on each other.
Sell the same day where possible.

Common post-harvest mistakes#

Mistake	Result
Bunches left in the sun after cutting	Heat damage, uneven ripening later
De-handing on a hard concrete floor	Latex staining, bruising, contamination
Wash water left milky	Recontamination of every subsequent hand
Ragged crown cuts	Crown rot
Packing wet hands	Anaerobic decay in the box
Cold store below 13 °C	Chilling injury — irreversible
Mixed grades in one box	Rejections on inspection; buyer loses trust
No block/harvest traceability	Cannot pass audit; no way to fix a source problem

Next steps#

Ripen to specification: Ripening.
Build the quality system: Quality and food safety.
Sell it: Marketing and value chain.