Post harvest Fundamentals: Temperature, Moisture and the Cost of Delay

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Between 5 and 25 percent of the fruit and vegetables that leave an Australian farm gate are never eaten. Disease and oversupply account for some of it. A great deal of the rest comes down to two things: temperature and packaging.

This is a guide to the fundamentals — where losses actually originate, why the hours immediately after harvest matter more than any other, and what a cool room is really doing to your produce while it sits there.

Where the losses actually come from

The figure most often quoted is Kader’s estimate that 5 to 25 percent of fruit and vegetables leaving the farm gate never get consumed. But the headline number understates the damage, because the economic cost of a postharvest disorder runs well beyond the value of the fruit that was thrown away.

There is the direct loss to the grower on the affected batch. There is the flow-on loss to packers and marketers handling it. If the problem recurs, there is the cost of the monitoring systems put in place to check every line and isolate the bad ones. And an intermittent, unpredictable disorder appearing in the market does something worse than any of these — it erodes trade confidence in the product, and that shows up as downward pressure on price across everything you sell.

The exposure is greatest for premium and branded lines. A differentiated product selling at a premium has more to lose from a quality failure than a commodity line does, because the premium depends on consistency. Years of work building a brand can be undone by a handful of poor consignments.

Harvest is a kind of amputation

Horticultural produce is alive and has to stay alive long after harvest. Like any living tissue it consumes oxygen and releases carbon dioxide.

Jobling’s framing is worth keeping in mind: for a plant, harvesting is a kind of amputation. In the field the fruit is connected to roots supplying water and leaves supplying food energy. Cut it away from both and it must inevitably die. Everything postharvest handling does is an attempt to delay that death for as long as possible.

Which means there is no universal answer. Spinach and apples, bananas and potatoes each have their own requirements, and the optimum handling for one is wrong for another. Growers, packers, exporters and retailers all need to know the specific needs of the product in front of them.

Field heat: the most expensive hours of the whole chain

In the paddock, the sun and the produce’s own respiration combine to heat it up — worst in the centre of a field bin, where there is no airflow and the heat has nowhere to go. This accumulated field heat has to come out fast, because every hour it stays in costs storage life at the far end.

The number worth remembering: strawberries respire nearly eight times faster at a field temperature of 25°C than at a storage temperature of 0°C. As Jobling puts it, one day left warm in the field sacrifices as much as eight days of storage life.

That ratio is why pre-cooling is not optional and why good intentions are not enough. Harvesting in the cool of the morning and keeping bins in the shade both help, but heat production of this order can only be controlled by active refrigeration.

Pre-cooling also needs more refrigeration capacity than cool storage does, which is why it is often best run as a separate step rather than expecting the cool room to do both jobs.

Method How it works
Hydro-cooling Cold water drenches; fast heat transfer, suits robust produce
Forced air cooling Air pulled through the stack; depends entirely on proper air distribution
Packing with ice Direct contact cooling; suits crops tolerant of wetting

Which one is right depends on the commodity. There is no default.

Why the cool room is drying your produce out

This is the part that catches people out, because it is the refrigeration itself doing the damage.

To hold a room at 0°C, the cooling coils have to sit appreciably below 0°C. Air passing over them gives up its moisture, which accumulates as ice on the coils. The lower the coil temperature, the more moisture comes out of the air. That now-dry, cold air circulates back into the room, warms slightly, and picks up moisture again — and the moisture it picks up comes from your produce.

So a well-run cold room is continuously pulling water out of whatever is sitting in it. Weight loss, shrivel and limpness are not signs the refrigeration is failing. They are what refrigeration does when nothing stands between the produce and the air.

Jobling states the remedy plainly: unless a plastic film or some other vapour barrier protects the product, water evaporates from it.

There is a second-order effect too. The more moisture freezing onto the coils, the more often the system has to run a defrost cycle — and every defrost cycle makes holding a stable temperature harder. Moisture loss and temperature instability are the same problem viewed from two angles.

Uniform temperature, and the short circuit that ruins it

A cool room average tells you very little. What matters is whether every part of the room is at that temperature, because only then can you safely run at the lowest and most effective setting for the crop.

If one corner runs warmer, the produce there ripens faster and your out-turn becomes mixed — the same consignment arriving at different maturities. Checking a wall thermometer will not reveal this. Core temperatures of the packages need checking at several points in the room, including at floor and ceiling level.

The hard part is that the room never stays still. Bulk bins and pallet loads are constantly rearranged as produce comes in and goes out, and each rearrangement changes the airflow. Maintaining even distribution through that is a genuine skill.

The specific failure to watch for is a short circuit — cooled air finding a direct path back to the coils instead of travelling through the stack. When that happens the system reports the room as being at temperature while whole sections sit starved of circulation and quietly warmer.

Maturity and handling

Maturity has no general definition, because it depends on what the product is for. We eat sprouted seeds, leaves, flowers, whole fruit, seeds and nuts — there is no single rule spanning that range. Maturity has to be defined per product, and in some cases per variety.

Standards matter for two reasons. They give the consumer a floor on quality, and they give a hand-picking crew something workable to follow. Most horticultural produce is still harvested by hand, and a simple colour and size guide is what turns an abstract maturity target into something a picker can apply consistently.

Care during harvest repays itself later. Fewer bruises and injuries mean less disease and better value at the far end. Reducing the sheer physical effort of picking helps here more than it might appear — conveyors for crops like lettuce and celery, cherry pickers for tree crops. A crew that is less exhausted has more attention left for handling the fruit gently.

Some compromise is unavoidable. Produce destined for long-distance transport often has to be picked firmer and less mature than is ideal for flavour, simply so that it travels. That is the trade being made every time fruit is available out of season, and postharvest handling is what determines how much of the eating quality survives it.

What this means in practice

The hours after cutting are worth more than the days after packing. On the strawberry figure, a day of field heat costs roughly eight days of storage life. No downstream intervention recovers that.

Pre-cooling is a separate job from cool storage. It needs more capacity than holding does, and expecting one room to do both means doing neither well.

Measure cores, not air. Several points, floor to ceiling. A room at temperature on average can still be delivering mixed out-turn.

Assume the cold room is taking moisture out of your produce, because it is. The question is only whether anything stands in the way.

A vapour barrier is doing two jobs at once. It holds moisture in the produce, and it reduces the moisture load reaching the coils — which means fewer defrost cycles and a more stable room for everything else stored alongside it.

Sources

Jobling, J. (2002). Postharvest management of fruit and vegetables. Good Fruit and Vegetables Magazine, January 2002. Sydney Postharvest Laboratory Information Sheet.

Kader, A.A. (1992). Postharvest biology and technology: an overview. In Postharvest Technology of Horticultural Crops, Publication 3311, University of California, pp. 15–20.

Wills, R.B.H., McGlasson, W.B., Graham, D. and Joyce, D. (1998). Postharvest: An Introduction to the Physiology and Handling of Fruits, Vegetables and Ornamentals. NSW University Press, Sydney.

Related reading

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Ethylene Management in Postharvest Handling

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Ethylene is invisible, nearly odourless, and almost never measured in commercial handling. That combination is why it does so much damage — the losses show up in the consumer’s kitchen, days after the produce has left your control, and rarely get traced back to the cold room where they started.

This is a practical guide to managing it: which crops produce it, which crops suffer from it, where it comes from in a packing shed, and what actually works to reduce it.

The two classes of produce

Every crop falls into one of two groups. Climacteric produce releases a burst of ethylene as it ripens, alongside a rise in respiration — these are the fruits that continue ripening after harvest, softening, changing colour and sweetening. Non-climacteric produce does not. It will soften slightly, lose green colour and eventually develop rots, but it never improves in eating quality after picking.

The practical test is simple: does it ripen after harvest? If yes, it is climacteric, and it is a source of ethylene. If no, it is non-climacteric, and it is a victim of it.

Climacteric — produces ethylene Non-climacteric — damaged by it
Apple, pear, quince Cherry, blackberry, strawberry
Apricot, nectarine, peach Eggplant, cucumber, pepper
Mango, avocado, banana Lemon, orange, mandarin
Tomato, sapodilla Watermelon, honeydew melon
Rockmelon, passionfruit Grape, lychee, loquat

Classification after Kader (1992), Postharvest Technology of Horticultural Crops, p. 16.

Where the ethylene in your shed comes from

There are two sources, and only one of them is obvious.

The produce itself. Any climacteric fruit in the room is generating ethylene continuously. Over-ripe and rotting fruit generate more.

Combustion engines. Ethylene is a component of petrol engine exhaust. A gas-powered forklift working inside a cold room, or a truck left idling during loading, is actively dosing your produce.

A Sydney-region survey of wholesale markets, distribution centres and retail stores found ethylene concentrations in the range of 0.017 to 0.06 ppm during normal marketing — enough, on the research available, to cost a meaningful share of remaining shelf life.

The effect accumulates. Produce may spend only a short time in any one location, but each moderate exposure adds to the last. A chain of individually unremarkable exposures ends as a very short life in the consumer’s kitchen — and the quality loss is not visible at the point of sale, which is precisely why it goes unaddressed.

What the damage actually looks like

Ethylene accelerates ageing. In green tissue — leafy vegetables, cucumbers — it drives chlorophyll loss and makes the product more susceptible to rots. Beyond general senescence, several crops show distinctive disorders:

Crop Symptom
Lettuce Russet spotting — dark brown spotting along leaf mid-ribs
Carrot Bitterness from isocoumarin production — reported at concentrations as low as 0.5 ppm within two weeks of storage
Potato Sprouting
Asparagus Toughening
Cut flowers Flower and leaf drop — carnation, delphinium, freesia, gypsophila and Geraldton wax are all sensitive

The carrot figure is worth pausing on. Bitterness at 0.5 ppm is not a theoretical laboratory threshold — it is well within the range a carton of carrots could encounter sharing a cold room with ripening fruit.

Controlling the sources

Most of this costs nothing but discipline.

Separate the classes. Green leafy vegetables should not share storage or transport with ripening apples, pears, mangoes, tomatoes or bananas. Mixed loads are the single most common avoidable exposure.

Use electric forklifts around ethylene-sensitive product rather than gas-powered ones.

Do not leave engines idling in enclosed spaces, including during loading and unloading.

Remove over-ripe and rotting fruit from storage and handling areas promptly. They are strong local sources.

Increase ventilation where practical — on the assumption that the incoming air is genuinely ethylene-free, which is not guaranteed near a loading dock or a road.

Removing what you cannot prevent

Source control has limits. Once produce is sealed in a carton and moving through a chain you do not control, the ethylene it generates has nowhere to go.

The established chemical method is potassium permanganate, which oxidises ethylene into carbon dioxide and water. It does not mask the gas or slow its production — it destroys the molecule.

On format: the Sydney Postharvest Laboratory guidance is that efficient scrubbing depends on spreading the potassium permanganate across as large a surface area as possible — in trays, or within highly permeable bags. Reaction rate is limited by contact between gas and reagent, so a compact mass of media works poorly regardless of how much of it there is.

That is the reasoning behind the sachet format: a permeable envelope holding a thin, distributed layer of impregnated media, placed inside the carton where the ethylene is actually generated rather than in the room outside it.

For cut flowers, silver thiosulfate applied as a stem pulse protects against ethylene by a different route — the flowers take it up and it blocks the response rather than removing the gas.

1-MCP (1-methylcyclopropene) blocks ethylene receptors and is active at very low concentrations. Note on currency: the source material for this section dates from 2000, when 1-MCP was registered in Australia for ornamentals only. It has since been registered for food crops in many markets. Check current registration status for your crop and jurisdiction.

When ethylene is the tool, not the problem

Controlled ripening is the deliberate use of the same gas. Applied under managed conditions, it lets climacteric fruit be presented ready to eat — the reason a consumer can buy an avocado for dinner tonight rather than one that needs four days on the bench.

Fruit Temperature Ethylene Treatment time
Avocado 18 – 21°C 10 ppm 24 – 72 hrs
Banana 15 – 21°C 10 ppm 24 hrs
Kiwifruit 18 – 21°C 10 ppm 24 hrs
Persimmon 18 – 21°C 10 ppm 24 hrs
Tomato 13 – 22°C 10 ppm Continuous

Commercial ripening generally runs between 1 and 100 ppm at 15 to 21°C and 85 to 90% relative humidity, with the exact combination varying by crop.

Ethylene is also used pre-harvest in the form of ethephon, which releases it in the field — for fruit thinning in apples and cherries, loosening nuts before harvest, colour development in apples, degreening citrus, inducing flowering in pineapples, and promoting lateral branching in potted azaleas and geraniums.

Ripening conditions after Wills, McGlasson, Graham and Joyce (1998), Postharvest, 4th edition, p. 209.

Sources

Jobling, J. (2000). Postharvest ethylene: a critical factor in quality management. Good Fruit and Vegetables Magazine 11, December 2000. Sydney Postharvest Laboratory Information Sheet.

Kader, A.A. (1992). Postharvest biology and technology: an overview. In Postharvest Technology of Horticultural Crops, Publication 3311, University of California, pp. 15–20.

Reid, M. (1992). Ethylene in postharvest technology. In Postharvest Technology of Horticultural Crops, Publication 3311, University of California, pp. 97–108.

Warton, M.A., Wills, R.B.H. and Ku, V.V.V. (2000). Ethylene levels associated with fruit and vegetables during marketing. Australian Journal of Experimental Agriculture 40(3): 465–470. View at CSIRO Publishing

Wills, R.B.H., McGlasson, W.B., Graham, D. and Joyce, D. (1998). Postharvest: An Introduction to the Physiology and Handling of Fruit, Vegetables and Ornamentals, 4th edition. UNSW Press, Sydney.

Related reading

Carrying ethylene-sensitive crops through a long chain?

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Postharvest Ethylene Research: What the Studies Actually Found

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Most postharvest guidance treats 0.1 µL/L as the ethylene level where damage begins. Three Australian studies published between 1999 and 2001 suggest that figure is far too high — and that the ethylene levels found in ordinary supermarkets, distribution centres and wholesale markets are already costing shelf life every day.

Here is what the research found, what it means in a packing shed, and where it stops short.

1. The damage threshold is far lower than the industry assumes

Wills, Ku, Shohet and Kim tested 23 kinds of non-climacteric fruit and vegetables across a range of ethylene concentrations, at both ambient and cold temperatures. They found storage life extended linearly as ethylene concentration fell logarithmically — and that produce held below 0.005 µL/L lasted roughly 60% longer than produce held at 0.1 µL/L.

Their conclusion was that the real threshold for ethylene action sits well below 0.005 µL/L, and that commercial storage never gets near it. Any step that reduces ethylene accumulation around non-climacteric produce will extend its postharvest life.

Wills, R.B.H., Ku, V.V.V., Shohet, D. and Kim, G.H. (1999). Importance of low ethylene levels to delay senescence of non-climacteric fruit and vegetables. Australian Journal of Experimental Agriculture 39(2): 221–224. View at CSIRO Publishing

2. Real supply chains sit well above that threshold

The obvious question is what ethylene levels actually occur in commercial handling. Warton, Wills and Ku answered it directly, taking more than 700 measurements over three years across wholesale markets, distribution centres, supermarket retail stores and domestic refrigerators.

Environment Mean ethylene level
Supermarket receival, storage and display 0.017 – 0.035 µL/L
Wholesale markets and distribution centres approx. 0.06 µL/L
Domestic refrigerator, no apples present 0.029 µL/L
Domestic refrigerator, apples present 0.20 µL/L

From this the authors proposed a working rating scale: at or below 0.015 µL/L, less than 10% of potential postharvest life is lost; at or above 0.1 µL/L, the loss is unacceptable.

Set the two studies side by side and the gap is clear. The best-performing environment measured — a supermarket cold room — still sits several times above the level at which produce reaches its full potential shelf life. A wholesale market or distribution centre sits higher again. The loss is not caused by a fault or a breakdown; it is the normal operating condition of the chain.

Warton, M.A., Wills, R.B.H. and Ku, V.V.V. (2000). Ethylene levels associated with fruit and vegetables during marketing. Australian Journal of Experimental Agriculture 40(3): 465–470. View at CSIRO Publishing

3. It matters most for the most sensitive crops

The third study turned to climacteric fruit — the crops that ripen after harvest. Wills, Warton, Mussa and Chew held mature unripe mango, peach, custard apple, kiwifruit and tomato at 20°C under controlled ethylene concentrations, with kiwifruit and custard apple also tested at 0°C and 14°C respectively.

Time to ripen increased linearly as ethylene fell logarithmically, across the whole range tested. But sensitivity varied considerably between crops:

banana and kiwifruit > custard apple and mango > tomato, avocado and peach

The authors were careful about what follows from this. Because commercial ethylene levels are always above 0.005 µL/L, climacteric fruit cannot be held unripe as long as it theoretically could — but they concluded that active intervention to limit ethylene is warranted mainly for the most sensitive crops, not universally.

That caveat is worth taking seriously. It argues against blanket treatment and in favour of matching the intervention to the crop, the ethylene load and the length of the chain.

Wills, R.B.H., Warton, M.A., Mussa, D.M.D.N. and Chew, L.P. (2001). Ripening of climacteric fruits initiated at low ethylene levels. Australian Journal of Experimental Agriculture 41(1): 89–92. View at CSIRO Publishing

What this means for a packer

Assume ethylene is present. The measurements say it always is. Planning on the basis that a clean, well-run cold chain is a low-ethylene environment is not supported by the data.

Target the sensitive crops first. The 2001 sensitivity ranking is a practical priority list. If budget is limited, the return is highest on the crops at the top of it.

Match the method to the load. A high-ethylene-generating crop in a large carton is a different problem from a low-generating crop in a retail pack, and the same solution will not serve both. Later work by Wills and Warton on potassium permanganate absorbents found removal efficiency declined over time and suggested such absorbents suit lower ethylene-generating produce, with larger packages of high-generating produce requiring impractical quantities of absorbent. Sizing matters.

Consider the barrier as well as the scavenger. Reducing ethylene accumulation and slowing respiration are two different levers. Modified atmosphere packaging addresses the second; ethylene absorption addresses the first. Long chains and sensitive crops often need both.

Further reading

Wills, R.B.H. and Warton, M.A. (2000). A new rating scale for ethylene action on postharvest fruit and vegetables. In Improving Postharvest Technologies of Fruits, Vegetables and Ornamentals, pp. 43–47. Artés, F., Gil, M.I. and Conesa, M.A. (eds). International Institute of Refrigeration, Murcia, Spain.

Wills, R.B.H. and Warton, M.A. (2004). Efficacy of potassium permanganate impregnated into alumina beads to reduce atmospheric ethylene. Journal of the American Society for Horticultural Science 129: 433–438.

Jobling, J. (2002). Postharvest management of fruit and vegetables. Good Fruit and Vegetables Magazine, January 2002. Sydney Postharvest Laboratory Information Sheet.

Sydney Postharvest Laboratory. Postharvest ethylene: a critical factor in quality management. Information Sheet.

Related reading

Not sure which crops in your program are most exposed?

Biopac engineers MAP bags to the respiration rate of each crop and sizes Fresh Up® ethylene absorption to the load and carton. Tell us the crop, the carton and the length of the chain, and we will tell you what the numbers suggest.

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Banana: Bruise-Free Packing with the Biopac MAP Bag

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Standard vacuum packs for banana cartons need the plastic torn or stripped away at the hand holes to fit the bunch through. It’s a small step in the packing line, but it’s also a bruise and scar risk that happens before the fruit has even left the plant. Sumifru Philippines’ New Products team ran an independent trial in 2011 to test whether Biopac’s specially designed vacuum bag — built with hand holes that don’t need tearing or stripping — could hold up through a full ripening cycle without any loss of fruit quality.

The Packing Problem With Standard Vacuum Bags

Fitting a banana bunch through a standard vacuum bag usually means tearing or stripping plastic around the hand holes so the crown clears the opening. That operation puts pressure directly against the fruit at exactly the point where it’s most exposed, and it’s a common source of bruising and surface scarring that shows up later in the box, not at the point of packing.

The Trial

Sumifru Philippines (New Products, Jan Gilbert S. Murao II) tested the Biopac bag’s hand-hole design against this problem directly. The objective was straightforward: validate that bananas would ripen normally and reach acceptable quality without tearing or stripping the vacuum pack during packing.

Biopac bag hand-hole design eliminating the tear and strip step

The Biopac bag’s hand-hole opening is designed to clear the crown without tearing or stripping the plastic. Source: Sumifru Philippines trial report.

Banana bunches packed in Biopac bag inside export carton

Ripening Results

Bananas packed in the Biopac bag turned yellow following the New Zealand ripening pattern normally, with no tearing or stripping required at any point in the process. Moisture in the peel was observable three weeks after harvest, and the pulp remained firm. Peel colour change was delayed by one day compared to the standard vacuum pack — a difference worth factoring into ripening room scheduling rather than a quality concern in itself.

Banana bunches at colour stage 5 showing moisture in the peel

Appearance at colour 5 — moisture visible in the peel, consistent with normal ripening.

Brix and Firmness

An independent samples t-test (n=34) found statistically significant differences between the two pack types on both brix and hardness (p=.001 for each). The standard vacuum pack produced fruit with higher brix but softer pulp; the Biopac bag produced fruit with lower brix but firmer pulp at colour 5.

Pack Type Brix, Colour 5 (%TSS) Hardness, Colour 5 (kg/cm³) Brix, 72hrs After Colour 5 Hardness, 72hrs After Colour 5
Standard vacuum pack 17.60 .42 — —
Biopac bag 16.16 .45 18.76 .34

Banana bunches 72 hours after colour 5 at 18 degrees C

Bruise and Scar Reduction

Because the Biopac bag removes the tear/strip step entirely, bruising and scarring linked to that packing operation were avoided. This matters most at the point of packing, where fruit is handled most and quality damage is hardest to catch before it’s boxed and shipped.

Shelf Life and Crown Condition

At 72 hours after colour 5 (held at 18°C), crown rot was present but not severe, and some neck dehydration was observed. Worth monitoring on longer transit windows, but not a disqualifying result at this shelf-life point.

Why Ethylene Control Matters Alongside the Bag

Bananas are a climacteric fruit — they produce their own ethylene as they ripen, and that ethylene accelerates further ripening in a self-reinforcing cycle. Inside a sealed bag like the one tested here, any ethylene the fruit produces has nowhere to go, which is exactly why the packaging problem and the ethylene problem are connected rather than separate. Pairing the Biopac bag with a Fresh Up® ethylene absorber sachet or filter gives the sealed environment somewhere for that ethylene to be neutralised, rather than accumulating and pushing the fruit toward faster, less even ripening.

Banana crown showing mild crown rot and neck dehydration 72 hours after colour 5

The Practical Takeaway

This independent Sumifru Philippines trial validates a design detail that’s easy to overlook: how a bag fits around the crown matters as much as the barrier properties of the film itself. The Biopac bag’s hand-hole design removed a manual tear/strip step that’s a known bruise risk, while fruit still followed a normal New Zealand ripening pattern and reached firmer pulp at colour 5 than the standard vacuum pack. Crown condition at extended shelf life is worth watching on longer routes, but the core packing-quality question the trial set out to answer — does removing the tear/strip step compromise the fruit — came back negative.

Papaya: Faster Colour, Higher Brix — The Biopac MAP Bag in an Independent Fiji Export Trial

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Fijian papaya exports have grown fast — from around $700,000 in 2010 to close to $6 million the following year — and the industry’s biggest opportunity is shifting more of that trade from air freight to sea freight, where transit times to Australia run around 15 days. Longer transit means more time for quality to slip, which is exactly what a Queensland Department of Agriculture, Fisheries and Forestry (DAF) and ACIAR trial on Fiji Red papaya set out to test: does the right MAP bag hold fruit quality through three weeks of cold storage and still deliver good eating quality at the other end?

The Trial

Researchers packed heat-treated, disease-controlled Fiji Red papaya into one of five packaging treatments — PeakFresh, the Biopac MAP Bag (Z106 and Z108 models), Cling Wrap, or a sealed carton with a potassium permanganate (KMnO₄) sachet — then held fruit in cold storage at 10°C for three weeks before assessing quality over a 9-day shelf life period at 23°C.

Papaya bag treatments including the Biopac MAP Bag packed in export cartons

Papaya packed across both trial experiments, including the Biopac MAP Bag. Source: Henriod et al., Queensland DAF / ACIAR, 2012.

Headspace Gas Environment

The Biopac MAP Bag held headspace conditions close to the recommended optimum range for extending papaya shelf life, in both the Z106 and Z108 models — averaging 5–8% CO₂ and 7–9% O₂ over the three-week storage period, in line with published guidelines for controlled atmosphere storage.

Colour Development

Of all five packaging treatments tested, fruit held in the Biopac MAP Bag developed colour fastest — the Z108 model leading, closely followed by Z106 — both significantly ahead of the Sealed Box + KMnO₄ and PeakFresh treatments, reaching 20–30% more yellow colour by Day 4. By Day 6, fruit from both models had reached a colour break of over 90%.

Chart showing papaya colour break percentage over days after storage for five MAP treatments

Papaya fruit in PeakFresh and the Biopac MAP Bag photographed pre-storage through Day 6

Biopac MAP Bag fruit (Z106 and Z108 models) tracked from pre-storage through Day 6 of shelf life, alongside PeakFresh.

Flavour and Brix

Fruit from the Biopac MAP Bag cleared the minimum flavour acceptability threshold of 5.5 on a 9-point hedonic scale in both models — scoring 5.9 (Z106) and 5.6 (Z108) — with no off-flavours recorded in either. On Brix, the Biopac MAP Bag placed among the highest of all treatments tested in both models, behind only the unpackaged control fruit.

Bar charts comparing flavour scores and Brix levels across papaya MAP treatments

The Practical Takeaway

Across three weeks of cold storage and a full shelf-life assessment, the Biopac MAP Bag delivered the fastest colour development of any treatment tested, in both the Z106 and Z108 models, alongside strong Brix and flavour results that cleared the acceptability threshold. As with most shelf-life trials run under real orchard and climate conditions, background disease pressure was a limiting factor across the study overall — the trial’s authors note that future work focused on disease control would help fully realise commercial outturns. For papaya exporters weighing up packaging options for extended sea freight, this independent trial adds solid published evidence behind the Biopac MAP Bag’s performance.

How a MAP Bag Shapes the Banana Ripening Curve

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Ripening bananas is a balancing act. Ripeners need fruit to move predictably from green through to the yellow the shopper wants — evenly, and at a pace that gives the supermarket a workable selling window. Fruit that races to full ripe, or ripens unevenly across a carton, is fruit that gets marked down or thrown out.

A 2011 ripening trial run with Gracio in New Zealand shows how a Biopac MAP bag changes that curve — slowing and evening out the march to full ripe.

The trial setup

Fruit was packed on 30 June 2011 and arrived in New Zealand on 15 July. Three 13 kg cartons went into a commercial ripening cycle on 16 July: a five-day programme stepping down from 17.5 °C to 14.5 °C, with an extra day added at 16.5 °C. Fruit came out of ripening on 22 July and was then tracked by colour stage over the following two weeks, with a temperature recorder confirming holding temperatures of 12–14 °C throughout.

This was a ripening test, not a shelf-life comparison — the trial deliberately used no control samples. The aim was to see how fruit behaved through and after ripening inside the Biopac MAP bag.

One honest finding first: sealed vs vented

The trial ran two configurations. Some cartons held fully sealed retail-bagged fruit inside the MAP; one held loose, un-bagged fruit inside the MAP.

The fully sealed retail bags held the fruit back. Those bananas ripened unevenly and only reached stage 2.5–3, and the trial’s own note was that a vent hole in the retail bag would help. The loose fruit inside the MAP bag, by contrast, ripened very evenly to stage 3.5 and then progressed cleanly. It is a useful result: the MAP bag is the right tool for managing the ripening atmosphere, but the fruit needs some air exchange rather than being sealed airtight inside a second consumer bag.

The ripening curve

Tracked from removal, the fruit climbed steadily and predictably through the colour stages rather than jumping to full ripe.

Line chart of banana colour stage over time in a Biopac MAP bag from the Gracio trial

The first fruit came out of ripening at stage 3.5, reached stage 5.5 after five days, and did not hit stage 7 — fully ripe — until eleven days later. The second batch, stored green for seven days before ripening, came out at stage 4 and reached stage 5.5 in four days once opened. Fruit from that batch that was left sealed for a further three days took five to six days to reach the same stage — again showing how much the atmosphere inside the bag slows the clock.

Why ethylene drives this curve

Bananas are climacteric fruit — once ripening starts, they produce their own ethylene, and that ethylene drives further ripening in a self-reinforcing cycle. That’s the biology behind the numbers above: commercial ripening rooms use exogenous ethylene gas to trigger the process in the first place, but from that point on the fruit’s own ethylene output takes over and keeps pushing it toward stage 7. A modified atmosphere — lower oxygen, higher CO₂, inside the Biopac bag — slows both how much ethylene the fruit produces and how strongly it responds to it, which is what stretches the curve out and keeps colour even across the carton rather than racing ahead unevenly.

Ethylene management doesn’t stop once fruit leaves the ripening room, either. A Fresh Up® ethylene absorber sachet or filter used earlier in the supply chain, alongside the Biopac bag, gives ethylene the fruit produces in transit somewhere to go — rather than letting it accumulate and push ripening ahead of schedule before the fruit even reaches the ripener.

What the fruit looked like

Bananas at early ripening stage, still largely green

Early stage — still green, freshly out of ripening.

Bananas at mid ripening stage, mostly yellow

Mid stage — colouring evenly toward stage 5.5.

Bananas approaching full ripeness, deep yellow

Ripe — full yellow, around stage 6.

Bananas at full ripeness, stage 7

Fully ripe — stage 7, even colour across the hand.

Why a slower curve is worth money

For a ripener or a retailer, the value here is control. Fast, uneven ripening compresses the selling window and drives waste — fruit arrives on the shelf at mixed stages and tips over into overripe before it sells. A slower, more even curve does the opposite: it holds fruit at a saleable stage for longer and makes the stage on arrival predictable.

The trial noted that current liners were taking about four days to move fruit from stage 4 to stage 7 in winter. Stretching that progression out, while keeping the colour even across the carton, is a meaningful gain for everyone downstream of the ripening room.

For bananas, the takeaway is that a MAP bag is not just about holding fruit green in transit — it is a tool for shaping the whole ripening curve, giving a longer, more predictable path from green to gold.

One Trial, Six Crops: What Ethylene Control Does to a Mixed Load

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Most shelf-life trials test one crop at a time. This one did something more useful: it loaded a mix of produce into two rooms — one with Biopac ethylene control technology running, one without — and left them side by side for up to 23 days. Same fruit, same temperatures, same load. The only variable was whether ethylene was being removed from the air.

The result is one of the clearest demonstrations we have of what ethylene control is worth across a real mixed load.

The trial setup

The trial was run at Turners & Growers Imports, Mt Wellington, Auckland, starting 24 May 2010. A range of produce was chosen to simulate a full mixed-load environment: lemons, full-red tomatoes, rockmelon, bananas, table grapes and iceberg lettuce.

Each line of produce was split evenly across two pallets. One pallet went into an ethylene-controlled environment, the other into an uncontrolled environment. Samples were assessed weekly, and photographed each time.

There was a second arm to the trial that makes it more valuable than a straight cold-storage test. At intervals, samples were pulled out of storage and held at ambient temperature to simulate what happens on the retail shelf after the cold chain ends. That “storage plus ambient” data shows how much protection carries through to the point of sale.

One note on the produce: the tomatoes and lemons were deliberately chosen at full-ripe, to show what ethylene control can do even with produce that is already well advanced. The banana line was excluded from the results — the trial recorded that storage temperature was never right for the fruit, so those samples were treated as void.

The headline result

Bar chart comparing marketable percentage of five crops with and without ethylene control in the T&G mixed-load trial

Across every valid crop, the ethylene-controlled pallet held marketable quality substantially longer. The gap was widest where it mattered most commercially — grapes and rockmelon — and visible in every single line of produce.

Grapes — the clearest result in the trial

At 23 days, the difference was total. The uncontrolled grapes were rotten and completely unmarketable. The controlled grapes had roughly 5% of berries affected, with the rest still saleable.

Table grapes under ethylene control at 23 days, still firm and marketable

Ethylene controlled — 23 days

Around 5% of berries affected, the rest marketable.

Table grapes without ethylene control at 23 days, rotten and unmarketable

Uncontrolled — 23 days

Totally rotten and unmarketable.

Rockmelon — softness and skin mould

At 15 days, three of the four uncontrolled melons were unmarketable from softness and skin fungal growth. All four controlled melons were still marketable, showing only very early softening.

Rockmelons under ethylene control at 15 days, clean and marketable

Ethylene controlled — 15 days

All four marketable, only very early softening.

Rockmelons without ethylene control at 15 days, showing skin mould

Uncontrolled — 15 days

Three of four unmarketable — soft, with skin fungal growth.

Lemon — the shelf-simulation test

The lemon comparison is the one that speaks most directly to retail. After 7 days of storage followed by 16 days at ambient temperature — mimicking a real journey to the shelf and beyond — the uncontrolled fruit had rots developing across the sample. The controlled fruit had a single rotten fruit out of thirteen, with the rest marketable, despite the lemons starting full-ripe.

Lemons under ethylene control after storage plus ambient, mostly marketable

Ethylene controlled — 7d storage + 16d ambient

One of thirteen rotten, the rest marketable.

Lemons without ethylene control after storage plus ambient, with rots

Uncontrolled — 7d storage + 16d ambient

Rots developing across the sample.

Tomato — fungal growth held off

The tomatoes were full-ripe going in, which makes the result notable. At 23 days the uncontrolled fruit showed fungal growth on a quarter of the sample with 70% pitting. The controlled fruit had no fungal growth at all, with pitting on 60%.

Full-ripe tomatoes under ethylene control at 23 days, no fungal growth

Ethylene controlled — 23 days

No fungal growth. Pitting on 60%.

Full-ripe tomatoes without ethylene control at 23 days, with fungal growth

Uncontrolled — 23 days

Fungal growth on 25%, pitting on 70%.

Lettuce — colour and structure

Lettuce is highly ethylene-sensitive, and the trial showed it. At 15 days the uncontrolled lettuce had severe rots; the controlled lettuce held good colour with no rot, sitting just outside marketable condition. Neither sample survived the full 23 days in saleable shape, but the controlled lettuce held its colour and structure markedly longer — an honest illustration that ethylene control extends the window rather than stopping the clock.

Iceberg lettuce under ethylene control at 15 days, good colour, no rot

Ethylene controlled — 15 days

Good colour, no rot. Just outside marketable.

Iceberg lettuce without ethylene control at 15 days, severe rots

Uncontrolled — 15 days

Severe rots showing.

What the mixed load tells you

The value of a mixed-load trial is that it reflects reality. Ethylene producers and ethylene-sensitive crops travel together constantly — in reefer containers, in cold rooms, in distribution centres. The ripe tomatoes and melons in this trial were producing ethylene; the lettuce, grapes and lemons were paying the price for it.

Removing ethylene from that shared air changed the outcome for every crop in the room:

  • Grapes: from totally rotten to 95% marketable at 23 days.
  • Rockmelon: from three of four gone to all four marketable at 15 days.
  • Lemon: from widespread rots to one fruit in thirteen, through storage and ambient combined.
  • Tomato: fungal growth eliminated at 23 days, even on full-ripe fruit.
  • Lettuce: colour and structure held markedly longer.

The banana line was voided on temperature grounds, and the trial was upfront about it — a reminder that ethylene control works alongside correct temperature management, not instead of it.

For anyone shipping or storing mixed produce, the takeaway is simple: the ethylene your ripe lines give off is quietly ageing everything around them, and controlling it protects the whole load at once.

What Packaging Format Does to Broccolini Over 15 Days

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Broccolini is one of the harder brassicas to hold. It respires fast, it is highly sensitive to ethylene, and its failure mode is visible: the florets yellow, the stems soften, and the cut base dries or browns. There is no hiding it at retail.

A shelf-life validation run by an Australian fresh produce packer in January 2014 put this to the test — comparing Lifepack® MAP bags against the packer’s existing retail bag and bulk liner, side by side, from the same bulk stock.

The trial setup

Broccolini was received as bulk product, weighed, and packed on the same day. All samples went into the same cool room at approximately 3–6 °C. Quality was assessed at packing (P+0) and again at P+4, P+7, P+12 and P+15.

The packer’s target shelf life for the product was greater than P+8.

Six formats were compared:

  • Lifepack® MAP 508 — 400 mm × 240 mm retail bag, 35 mm vented flap, folded base
  • Lifepack® MAP 506 — 400 mm × 240 mm retail bag, 38 mm vented flap, folded base
  • Lifepack® MAP 508N — 415 mm side-fold bag, 375 mm top width
  • Lifepack® MAP bulk liner — 550 mm × 385 mm
  • Standard retail bag — perforated, currently in use
  • Standard black bulk liner — currently in use

Because every bag was filled from the same bulk stock on the same day, any difference in how the product aged came down to the packaging itself.

What happened, day by day

Day P+4 — the condensation split

All samples were still fresh. The first real difference was moisture. There was no condensation at all inside the 508 and 506 bags, and only minor condensation in the 508N. The heaviest condensation by a clear margin was inside the standard retail bag.

Both bulk formats still looked comparable at this point — firm, with fresh florets.

Day P+7 — bulk packing fails

This is where the trial produced its cleanest result, and it had nothing to do with which film was used.

Both bulk formats were finished. The broccolini in the standard black liner and in the bulk MAP liner had yellowing heads and drying at the base of the stem. The assessor’s note on the bulk product was blunt — it still snapped when bent, but it looked aged, not fresh or appealing.

Everything packed into bags was still acceptable:

  • 508 — fresh and healthy, crisp green stems, good florets, stems still snapping. No condensation in any bag.
  • 508N — firm and crisp, no deterioration or discolouration, bags free of condensation.
  • 506 — all but one sample fresh; a single stem showed minor browning at the base. Water droplets present inside the bags.
  • Standard bag — condensation present and slight drying at the stem base, but quality still deemed acceptable.

The lesson at P+7 is simple: for a product that yellows this fast, an unsealed bulk liner does very little. Getting broccolini into a bag mattered more at this stage than which bag it was.

Day P+12 — the formats separate

By P+12 every sample was deteriorating, but to visibly different degrees.

The standard retail bag was called unacceptable: yellow floret heads and soft, bendy stems. Both bulk liners had progressed from yellowing to outright browning, with weak stems and extensive discolouration.

The 508 was also marked unacceptable — but for a different reason. Its heads were still green with only early-stage yellowing, and the stems still snapped under pressure rather than bending. What failed it was the cut end: 75% of stems showed black or brown rot at the base.

The 508N showed a strong brassica odour on opening, with florets beginning to deteriorate and yellowing underway.

The 506 was the standout. Only minor yellow pigmentation at the edges of the floret, with the majority of the head still vibrant green. No browning at the base, only slight drying. It was explicitly recorded as the best of all samples on Day P+12.

That is the headline: on the same day the packer’s existing retail bag was written off, broccolini in the 506 was still green and saleable.

Broccolini florets in a Lifepack MAP bag at day 12, still vibrant green

Lifepack® MAP bag — Day P+12

Majority of the head still vibrant green, no browning at the base. Recorded as the best sample on the day.

Broccolini from a bulk liner at day 12, florets yellowing

Bulk liner — Day P+12

Yellowing through the floret head, stems weakening.

Broccolini from a bulk liner at day 12, heavily yellowed and discoloured

Bulk liner — Day P+12

Advanced yellowing and discolouration. Bulk formats were already unacceptable at P+7.

Both bulk liner formats shown. All photographed on the same assessment day, from the same bulk stock.

Day P+15 — the end point

The 508N and 506 were carried through to P+15. Both showed very evident deterioration and were rated unacceptable. Nothing in this trial held quality to P+15.

Chart comparing last day at acceptable quality for broccolini across six packaging formats at 3-6 degrees Celsius

Weight loss

Weight loss was low across every format, which tells you the quality differences here were driven by respiration and ethylene response rather than dehydration.

Format Weight loss range Measured to
Lifepack® MAP 506 0–0.8% P+15
Lifepack® MAP 508 0–0.4% P+12
Lifepack® MAP 508N 0.7–1.7% P+15
Standard retail bag 0.4% P+12

Over the full 15 days, the 506 held weight loss to a maximum of 0.8% — the tightest result of any format run to that point.

Why yellowing is the metric that matters

Broccolini is a brassica, and brassicas yellow in response to ethylene. Chlorophyll breaks down, the floret shifts from green to yellow, and the product becomes unsaleable long before it becomes inedible. Every failure point in this trial — the bulk liners at P+7, the standard bag at P+12 — was a colour failure, not a weight or texture failure.

That is why a packaging film’s job with this crop is to slow respiration and hold the atmosphere around the product stable, rather than simply to contain it.

The practical takeaway

  • Bulk liners underperform for broccolini. Both bulk formats were unacceptable by P+7, ahead of every bagged format.
  • Bag format matters as much as the decision to bag. All bagged samples looked similar at P+7 but had clearly diverged by P+12.
  • Condensation is an early warning. The standard bag showed the heaviest condensation from P+4 and was one of the first bagged formats to fail.
  • The 506 gave the widest margin. It was the only format still holding vibrant green florets and a clean stem base at P+12.
  • P+8 remains the honest call. The packer’s own conclusion was that shelf life should not be pushed past P+8 — but the right bag gives you real headroom inside that window rather than sitting on the edge of it.

If you are packing broccolini or other brassicas and losing product to yellowing before it reaches the shelf, the format of the bag is worth testing before anything else in the chain changes.

Packaging Is 10% of the Energy in Your Food — It Protects the Other 90%

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Australia wastes around 7.6 million tonnes of food every year — roughly 312 kilograms for every person in the country. The cost sits near $36.6 billion annually, about 1.4% of GDP. Those are national figures, and they get quoted often enough that they’ve lost some of their sting.

Here’s the part that matters to anyone growing, packing or exporting fresh produce: horticulture accounts for roughly half of Australia’s total food waste by volume. Not households. Not restaurants. Fruit and vegetables, lost somewhere between the tree and the shelf.

Where the losses actually happen

The national food waste baseline breaks down by supply chain stage:

  • Primary production — 22%
  • Processing and manufacturing — 17%
  • Distribution — 3%
  • Wholesale and retail — 7%
  • Households, hospitality and institutions — the remaining 51%

Add the first four together and almost half of Australia’s food waste occurs before the consumer ever sees the product. That’s the postharvest window — and it’s the window packaging operates in.

CSIRO’s mapping of horticultural loss put it in tonnes: up to 626 kilotonnes lost during production, and up to 830 kilotonnes lost during packing and processing. Overall, Australia loses an estimated 18–22% of its fruit and vegetable production before it ever reaches retail.

At farm level the numbers vary enormously by crop. Growers report anywhere from 14% to 38% of a crop lost on farm, with the average sitting around 20% per farm. In total that’s close to one million tonnes of produce that never reaches market — worth an estimated $2.5 billion a year.

And every kilogram of it carries the full cost of the inputs already spent: water, fertiliser, crop protection, labour, energy, land. The loss isn’t the produce. The loss is everything that went into growing it.

The packaging objection — and the number that answers it

Packaging is an easy target. It’s visible, it’s plastic, and it ends up in a bin. Produce loss, by contrast, is invisible — it happens in a shed, a container, a cold room, a distribution centre. Nobody photographs it.

An RMIT University study prepared for CHEP Australia put the two side by side and measured the energy involved at each stage of the food supply chain. The finding is worth sitting with:

Packaging accounts for around 10% of the total energy in a person’s weekly food. It exists to protect the other 90%.

That’s the whole argument in one line. When packaging fails and produce is dumped, everything upstream — the water, the growing, the harvest, the cold chain, the freight — is written off with it. The environmental impact of the food supply chain vastly exceeds the impact of the packaging protecting it.

Which leads to a conclusion that sounds wrong until you’ve seen the numbers: for highly perishable produce, the lower-impact outcome is sometimes more packaging, not less. Light-weighting a carton until it crushes in transit doesn’t save anything. It just moves the waste from the packaging bin to the produce bin, and multiplies it on the way.

What the research says works

The same report catalogued the primary packaging technologies capable of extending shelf life. Two of them describe exactly what postharvest fresh produce needs:

  • Modified atmosphere packaging (MAP) — the gas composition inside the pack is controlled and then held there by a high gas-barrier film. The effect is to slow the produce’s respiration rate and suppress microbial growth. Less respiration means slower senescence, which means longer shelf life.
  • Ethylene scavengers — chemical reagents in sachet or film form that absorb ethylene from the pack atmosphere. Removing ethylene delays ripening and extends the shelf life of fresh produce.

The report’s formal recommendations to industry included the adoption of new packaging materials and technologies — naming modified atmosphere packaging specifically — as a means of extending shelf life and reducing waste in the supply chain.

That’s not a packaging supplier’s marketing claim. That’s a university research centre, commissioned by a global logistics company, telling Australian industry what to do.

The banana case study

The same report examined the Australian banana supply chain in detail, and it’s the closest published parallel to what we do.

Between 10% and 30% of the total banana crop is rejected at the pack house for failing to meet customer specification — around 37,000 tonnes a year. On top of that, NSW Department of Primary Industries trials tracked physical damage through transit and found neck injury occurring mainly between farm and distribution centre, with bruising and skin marking increasing sharply between the distribution centre and the retail store.

Two packaging changes addressed it. Moving to a stronger, taller shipper almost eliminated neck injury in transport. And packing the fruit into bags rather than standard carton liners increased the shelf life of the product.

That second point is the one to notice. A liner contains fruit. A properly engineered bag manages the atmosphere around it. The difference between the two is measured in days of shelf life — and in an export chain, days of shelf life are the difference between a sale and a claim.

The misconception that undoes the work

There’s a final finding worth flagging, because it costs money quietly.

UK consumer research found that people are largely unaware of what packaging does for freshness — and a significant number hold the opposite belief, assuming that keeping produce in its packaging makes it spoil faster. The practical result is that they remove produce from the pack after purchase, or pierce the film to “let it breathe.”

For a MAP bag, that’s catastrophic. The entire function of the bag is the equilibrium atmosphere it establishes inside. Puncture it and the atmosphere equalises with the room, respiration returns to full rate, and the technology stops working. The same thing happens at the retail end when packs are opened for display, and in the shed when a bag is opened to inspect fruit and then not resealed.

Shelf-life technology only performs if the pack stays intact through to the consumer. That’s a training and communication problem as much as a packaging one — and it applies to staff at every handling point, not just shoppers.

What this means for a packing operation

Australia has committed to halving its food waste by 2030, in line with UN Sustainable Development Goal 12.3. Whatever happens at policy level, the commercial arithmetic already favours action: for every dollar invested in food waste prevention in Australia, the average return is estimated at $7–10.

For a grower or exporter, the levers in the postharvest window are narrow but effective:

  • Cool the produce fast and hold the cold chain. Nothing else works if this doesn’t.
  • Match the packaging to the crop, not to the pallet. Respiration rate, ethylene sensitivity and moisture behaviour differ by species and by variety.
  • Control ethylene, not just temperature. A cold chain break in an ethylene-loaded container does damage the cold chain alone can’t undo.
  • Protect pack integrity through to the customer. An opened MAP bag is a plain bag.

Lifepack® MAP bags are engineered per crop and variety, with the oxygen transmission rate, carbon dioxide transmission rate and water vapour transmission rate specified to that produce’s respiration profile — which is why a lychee bag and a broccoli bag are not the same film. Fresh Up® ethylene absorber sachets and filters handle the ethylene load inside the pack, and the two are usually specified together.

The research is clear enough on the principle. Packaging is not the food waste problem in fresh produce. Inadequate packaging is.

Apricot Softens When It Warms Up — Not When It’s Cold

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Apricot is the world’s third most cultivated stone fruit, and one of the most difficult to hold in condition after harvest. It’s strongly climacteric — meaning its ripening is driven by its own ethylene production — and that gives it a notoriously short marketable window (Regulation of apricot ripening and softening process during shelf life, Postharvest Biology and Technology). Because apricots are usually picked at low maturity, cooled, and then held to extend the supply period, the point where quality is won or lost isn’t in the cold room at all. It’s the moment the fruit warms up.

Why Cold Storage Alone Doesn’t Solve Apricot

At cold storage temperatures around 0–4°C, apricots hold their firmness well and don’t ripen significantly, because low temperature suppresses both metabolic activity and ethylene production (Interannual Variability in Apricot Quality, Horticulturae, 2025). Research indicates apricots can be held at 0°C for more than a month and still retain acceptable firmness (Stanley et al., 2013).

The problem is what happens next. The same research describes rapid softening on exposure to shelf-life temperatures around 20°C, driven by ethylene-triggered ripening processes that accelerate as the fruit warms. Studies tracking apricots through cold storage followed by simulated shelf life have measured ethylene production rates rising in all samples during the shelf-life period, with softening and weight loss both promoted by that phase (Impact of Cold Storage Temperature and Shelf Life on Ripening Physiology, PMC). The underlying mechanism is cell wall breakdown — pectin degradation and dissolution of the middle lamella — which is what turns a firm apricot into a soft one (Postharvest Biology and Technology).

So the real postharvest question for apricot isn’t just how cold you can hold it. It’s how much ethylene has accumulated around the fruit by the time it warms up — because that’s the trigger waiting to fire.

What the New Zealand Trial Tested

The New Zealand Institute for Plant & Food Research ran a storage trial on two apricot cultivars, ‘Clutha Gold’ and ‘Genevieve’, examining how modified atmosphere packages performed across extended cold storage. Alongside the packaging comparison, the trial included a specific test relevant to ethylene management: replicate bags were stored with an ethylene absorbent sachet, and matching replicates without. Oxygen, carbon dioxide and ethylene inside the bags were monitored weekly, and fruit quality was assessed after four or six weeks at 0°C followed by four days of shelf life at 20°C — the warm-up phase where apricot softening actually happens.

The Sachet Result

Two findings came out of the sachet comparison.

Ethylene was held at zero. In bags containing an ethylene absorbent sachet, ethylene inside the package remained at zero throughout the monitoring period. In the bags without a sachet, ethylene accumulated — rising through roughly the first three weeks of cold storage before eventually falling away again. That early accumulation window matters, because it overlaps precisely with the period when fruit is sitting in storage building toward its eventual warm-up.

Fruit was firmer. At both the four-week and six-week assessments, after the four-day shelf-life period at 20°C, sachet-treated fruit measured firmer than the matching no-sachet fruit across every package type tested. The trial’s own conclusion was direct: ethylene absorbent sachets were effective at reducing ethylene inside the packages and at maintaining fruit firmness.

Because this comparison was run across four different package types, the sachet benefit showed up independently of which package was used — it’s a result about ethylene management, not about any particular bag.

Why This Matters for Apricot Export

The independent research and the trial point at the same conclusion from different directions. Published work shows apricot softening is ethylene-driven and concentrated in the warm-up phase after cold storage. The trial shows that an ethylene absorbent sachet keeps ethylene at zero during storage and leaves the fruit measurably firmer once it has been through that warm-up. For an exporter, that’s the difference between fruit that arrives with usable shelf life ahead of it and fruit that softens on the retail shelf.

It’s also worth noting what the research says about duration. Studies have documented physiological disorders — juiciness loss and mealiness — developing in apricots held at 20°C after six weeks of cold storage at 0°C (Stanley et al., 2013). Apricot has a real storage ceiling regardless of packaging, and ethylene management extends quality within that window rather than removing the limit.

The Practical Takeaway

Apricot is a crop where ethylene control earns its place. Cold storage handles the storage phase reasonably well on its own; what it doesn’t do is remove the ethylene that has been accumulating around the fruit, ready to drive rapid softening the moment temperatures rise. An oxidative ethylene absorber placed inside the package addresses exactly that gap — and in this trial, doing so produced firmer fruit after the shelf-life period across every package type tested.

View the Biopac 2026 Product Catalogue (PDF)

References

  • Feng, R., Olsson, S., Woolf, A., Stanley, J., Varasteh, F., Marshall, R., White, A., & Petley, M. — Effect of MA packages on apricot storage, The New Zealand Institute for Plant & Food Research Limited (primary trial data).
  • Regulation of apricot ripening and softening process during shelf life by post-storage treatments of exogenous ethylene and 1-methylcyclopropene, Postharvest Biology and Technology — climacteric behaviour, cell wall and pectin degradation.
  • Interannual Variability in Apricot Quality: Role of Calcium and Postharvest Treatments During Cold Storage and Shelf Life, Horticulturae, 2025 — ethylene suppression at cold temperatures, rapid softening at shelf-life temperatures.
  • Impact of Cold Storage Temperature and Shelf Life on Ripening Physiology, Quality Attributes, and Nutritional Value in Apricots, PMC — ethylene production rates rising during shelf life.
  • Stanley, J., Prakash, R., Marshall, R., & Schröder, R. (2013) — apricot firmness retention at 0°C; juiciness loss and mealiness after six weeks.