Science
How breathing film keeps produce saleable
Produce keeps respiring after harvest. StayFresh film is engineered to let it breathe at the right rate, passively and without additives.
Inside conventional packaging
A sealed bag works against the produce
- Oxygen runs out. Below about 2% O2, fermentation starts: off-flavors, cell death and rot.
- CO2 builds up. Excess CO2 damages tissue and speeds microbial growth.
- Moisture is trapped. Condensation leads to mold, slime and decay.
- Ethylene accumulates. The ripening hormone has nowhere to go and the whole pack ages faster.
Inside a StayFresh pack
A self-regulating atmosphere
- Oxygen stays balanced. Enough O2 passes in to keep respiration aerobic, without excess.
- CO2 escapes. It passes out through the film before it reaches damaging levels.
- Humidity equilibrates. Water vapor moves through the film, so produce stays hydrated without condensation.
- Ethylene diffuses out. Ripening slows because the trigger is continuously vented.
Produce-specific calibration
Not all produce breathes the same
StayFresh grades differ in film structure and perforation density, matched to four respiration classes.
Very highLeafy greens, herbs, fresh-cut. Maximum gas exchange.
HighBroccoli, romaine, mushrooms. Calibrated against yellowing and browning.
MediumPeppers, cucumbers, tomatoes, avocados, stone fruit. Firmness retention.
LowGrapes, citrus, carrots, dates. Moisture control first.
Lab-verified results
Ambient-temperature trials (24°C)
Independent trials conducted by the StayFresh postharvest lab in November 2020, comparing StayFresh packaging with conventional packaging. Ambient trials show the upper end of the effect; in the cold chain, expect 30 to 40% longer shelf life.
Cold-chain trials on US crops are in progress; results are posted as each crop completes.
| Crop | Trial length | StayFresh weight loss | Conventional pack weight loss |
|---|---|---|---|
| Broccoli Nov 3–9, 2020 | 5 days | Green and fresh for 5 days | Yellowing in 2+ days |
| Mint (bulk) Nov 3–8, 2020 | 5 days | Green and fresh for 5 days | Withered within 2 days |
| Spinach Nov 4–8, 2020 | 96 hours | Bright green and crisp at 96 hours | Withered in 48 hours |
| Coriander Nov 4–8, 2020 | 4 days | Fresh and green through day 4 | Unsaleable by day 3 |
| Bell pepper Nov 18–29, 2020 | 10 days | Firm and vibrant for 10 days | Wrinkled and soft in 48 hours |
| Amaranthus Nov 1–3, 2020 | 48 hours | Green and fresh for 48 hours | Withered within 24 hours |
| Baby corn Nov 2–8, 2020 | 6 days | Firm and fresh for 6 days | Soft and browning by day 4 |
| Carrot Nov 3–8, 2020 | 5 days | Firm and fresh for 120 hours | Wrinkled and whitened in 48 hours |
| Eggplant Nov 3–9, 2020 | 19 days | Firm and saleable for 19 days | Unsaleable from day 6 |
| Guava Nov 2–13, 2020 | 11 days | Fresh and firm for 11 days | Softened in 2 to 5 days |
| Tomato (hybrid) Nov 2–13, 2020 | 11 days | Firm and fresh for 11 days | Over-ripening in 4 days |
| Bitter gourd Nov 4–8, 2020 | 96 hours | Green and fresh for 96 hours | Spoilt in 60 hours |
| Tomato (bulk) Nov 2–9, 2020 | 7 days | Saleable for 7 days | Over-ripened by day 5 |
| Okra Nov 3–11, 2020 | 7 days | Firm and fresh for 7 days | Blackened and soft by day 3 |
| Broccoli (trial 2) Nov 18–20, 2020 | 3 days | Green and fresh through day 3 | 29% loss by day 3 |
Research and development
The lab behind every grade
30+ years of postharvest science and polymer engineering. Our labs are open for packaging simulation, benchmarking and shelf-life trials with your produce before you commit to a SKU.
9 cold storage chambersTemperature-controlled rooms that simulate each step from harvest to retail shelf.
Microbiology labPathogen, mold and microbial screening on every film structure.
Postharvest analysisRespiration rate, ethylene, firmness, color, sugar and weight loss for each variety.
3-layer lab extruderNew co-extruded structures prototyped in-house to tune O2, CO2 and moisture transmission.
Automated packing labFlow-pack and lidding machines on site to simulate real production lines.
25+ film structuresMA/MH structures customized across 60+ produce types.
The StayFresh test
Free samples. Two weeks. Nothing owed if it does not work.
- Tell us your crop, bag or roll size, gauge and ship-to address.
- We send free samples cut to your spec: standard sizes within 3 business days, custom sizes in about 10 business days.
- Run them beside your current film on one line for two weeks and measure shelf life your way.
- Under a 30% gain: keep the samples, owe nothing.
- Over 30%: StayFresh beats your current per-unit film price by 10% for the first 12 months, no minimum on the first order.