For Lychee Growers, Selling Interstate Is Basically Exporting
Lychee is arguably Australia’s most postharvest-challenging fruit, and geography is a big part of why. Over 90% of the crop comes out of Far North Queensland, but the major markets — Sydney, Melbourne — sit up to 2,400 km away. At typical road freight speeds, that’s 2–3 days of transit for a fruit that, left unprotected, starts browning within 1–3 days at ambient temperature and shows commercial decay within just 6 days under refrigeration. For a Mareeba grower, selling to Sydney is effectively the same postharvest problem as exporting overseas.
What Actually Causes the Damage
Unlike most fruit, lychee produces minimal ethylene — the browning and decay driving rejection aren’t a ripening problem, they’re a moisture loss problem. The pericarp (skin) is thin and delicate, and starts losing water the moment the fruit is picked. That moisture loss drives pericarp browning, which is the single biggest reason lychee gets rejected by buyers — and it’s irreversible. Once the skin browns, no treatment brings it back.
The Trial: Deliberately Stacked Against the Fruit
A commercial trial run in Queensland tested Lifepack® MAP bags under conditions designed to stress-test the packaging, not flatter it. Lychee (cv. Kwai May Pink) was harvested in Mareeba on 10 December 2016 — and deliberately held for a week before packing, to simulate fruit that’s already lost freshness. It was then washed and packed wet, at 20°C, in 33°C summer heat — the exact scenario that causes problems with lower-quality packaging — and held in cold storage at 8–11°C.
Three treatments were compared at Day 14: a standard plastic liner (control), a Lifepack® MAP bag, and Lifepack® MAP with an added Absorpad.
The standard plastic liner showed very high condensation, with water pooling inside the bag. The result: major rot, heavy browning, pericarp black in places — commercially unsaleable.
The Lifepack® MAP bag showed no condensation and dry fruit. Result: only minor rot, fruit still red, firm, and marketable.
The official trial conclusion was direct: by Day 14, the plastic liner fruit was of unacceptable quality with major rot and very high condensation, while the Biopac treatments had only minor rot and no condensation — “taking into consideration that the fruit were already 1 week old when repacked.”
Why “Packed Wet” Matters More Than It Sounds
Standard lychee handling involves washing and hydro-cooling after harvest. With a low-quality MAP bag, growers have to wait for fruit to fully dry before sealing, or risk trapping moisture that causes rot — meaning wash, wait, check, dry, then pack. Every extra handling step bruises the delicate pericarp, and the delay before cold storage gives browning more time to start.
A properly engineered high-WVTR film changes this: wash, cool, and pack immediately. The film actively expels surface moisture within about 24 hours while still holding the 90–95% internal humidity the fruit needs to prevent browning — removing an entire handling step rather than just tolerating it.
Independent Scientific Backing
The Australian trial isn’t an isolated result. South Africa’s Agricultural Research Council (ARC Infruitec-Nietvoorbij) tested MAP packaging on lychee cv. Mauritius under simulated long-distance transport — 34 days at 2°C followed by 2 days at 14°C to simulate retail shelf conditions, with the atmosphere held around 17% O2 / 6% CO2. Weight loss and quality deterioration were prevented across the full storage period. Separately, peer-reviewed research comparing active MAP against untreated controls found shelf life more than doubled — from roughly 14.6 days to 29.6 days without signs of decay.
What This Means for Packaging
A Lifepack® MAP bag engineered specifically for lychee’s OTR, CTR, and WVTR requirements slows the enzymatic browning reaction by managing O2 levels (3–5%), suppresses Botrytis and fungal decay through elevated CO2 (5–10%), and — critically for this fruit — expels condensation through its high WVTR while maintaining 90–95% relative humidity to prevent the desiccation that drives browning in the first place. Because Australia doesn’t permit SO2 fumigation for domestic fresh lychee, this is also the chemical-free option for extending shelf life within regulatory limits.
The Practical Takeaway
The Rocklea trial wasn’t set up to make the packaging look good — it used week-old fruit packed wet in summer heat, about as unfavourable a starting point as a real shipment could have. Under those conditions, the standard liner fruit was unsaleable at Day 14 while the MAP-bagged fruit was still marketable. For a grower whose entire domestic market is a multi-day road trip away, that gap is the difference between a shipment that sells and one that’s written off.
Related: Full Lychee Post-Harvest Solutions brochure (PDF) · Lychee MAP Bag specifications
