Critical success factors in transporting mango fruit

Peter Hofman, Scott Ledger

Critical considerations Quality attributes at risk • Over-ripe / under-ripe fruit • Variable ripening between and within pallets • Poor skin colour • Chilling damage • Skin marks

Key issues • Temperature of fruit at loading • Pallet configuration in the container • Refrigeration capacity/air circulation/insulation • Gas accumulation (mainly carbon dioxide)

Quality risks; too ripe, uneven ripe, chilling

• Pre-cooling room temperature too high (>12ºC) • Pre-cooling time too short • Forced-air cooler not used or loaded incorrectly • Cool room not functioning properly

High fruit temperatures at loading

Loading warm fruit causes uneven ripening

Truck temperature 13ºC Average fruit temperature at loading 21ºC

Loading warm fruit causes chilling injury

Delivery air 6ºC below set point

Set point 13ºC

Chilling injury

Poor pre-cooling and container loading/performance Temperature setting too low - <10°C •Poor container loading •Poor container insulation (tautliners) •Fruit exposed on top of pallets near delivery air •Faulty equipment operation

Set temperature 18°C; fruit temperature at loading 19°C

Xsense tag 3 pallet layers down, 2nd row from front

Date and time

24/11 25/11 26/11 27/11 28/11 29/11

Tem

pera

ture

(o C)

15

20

25

30

35

40

2nd row from front (Xsense)2nd row from backLoaded

Unloaded

Poor cooling performance

Quality risk; too ripe, uneven ripe

• Fruit temperature too high at loading • Faulty refrigeration • Poor insulation, e.g. tautliners • Poor pallet loading • Air flow obstructed

Poor cooling performance

Good, even airflow is critical

✓

From Ledger 2012

Good, even airflow is critical

Under these conditions, the fruit on the outside of the pallet cooling down significantly more quickly than those in the middle. Temperature probe ring only the fruit on the outside of the pallet will often give a false indication

Refrigeration unit

Roof shoot

Ply sheet restricting both cold air delivery to front pallets, and return

of warm air to return vent

Cold delivery air vent

Warmer return air vent

Warmer return air through pallet

boards and/or floor vents

Restricted cold air to

front pallets

Cold air short-circuiting directly

to the return vent

Pallets

Transport do’s and don’ts

Pallet placed tight against bulkhead

✓

Gap left between bulkhead and 1st row of pallets – air short circuits

Transport do’s and don’ts

Stabilizing boards crossed to avoid blocking air flow under pallets

✓

Stabilizing boards and pads block air flow under pallets

• Carbon dioxide and other volatiles • High fruit temperatures causing high respiration • Poor ventilation

Gas accumulation

Risks; Skin spotting, poor colour, off flavours, WHS

Date (Nov 2012)

14th 15th 16th 17th 18th 19th

Car

bon

diox

ide

(%)

0

5

10

15

20

25

Loaded intocontainer

Removed fromcontainer

Temperature and carbon dioxide

Fruit temp. on arrival

24oC

17oC

• Loose packing and over-packing • Hard inserts • Incorrect stacking, pallet strapping • Pallets not secured effectively in vehicle • Rough roads and driving too fast

Quality risk; Transport rub, pallet collapse

Packing and roads/driving

Critical success factors • Fruit temperatures before loading

– Cool to within 2oC of transport temperature

• Correct pallet configuration – No gaps between first pallet and bulkhead, or – Ply from top of first pallet to bulkhead

• Don’t block return air flow – Use angled or fluted ply sheets

• Adequate refrigeration and insulation – Don’t use tautliners on long journeys

• Tight pack, soft inserts - drive to road conditions • Minimise carbon dioxide hazards

– Low fruit temperatures – Venting – Lime