Visit Us In-Store: 2/322 Hobart Rd, Youngtown TAS
Research news
Which pack and temperature work best for storing finger limes?
A recycled plastic blueberry punnet in an 8 °C cool room: that was the pick of nine packaging and temperature combinations for finger limes in a Western Sydney University trial, with about 80% of the fruit still saleable after eight weeks.
Finger lime is a native Australian citrus whose commercial value is growing, but like other citrus it is highly perishable. Researchers at Western Sydney University noted that little work had looked at how commercial packaging and storage temperature together affect its quality, so they stored ‘Red Champagne’ finger limes from a Queensland grower in three kinds of packaging at three temperatures for eight weeks (Noeparast et al., 2026).
What this means for your grow
If you grow or sell finger limes, this trial found that both the storage temperature and the pack made a difference. At 8 °C the fruit showed no chilling injury, visible fungal growth or shrivelling, while at 4 °C chilling injury appeared by Week 3 or 4 and fungal growth followed. Fruit held at room temperature (25 ± 2 °C) became unsaleable after about 10 days. These results come from one cultivar from one harvest season, with three replicate packages per treatment, so take them as a starting point rather than a rule for every finger lime.
What did the team do?
The fruit were commercially harvested on 25 August 2024 by Lilyshire Finger Limes at Cardwell in Queensland and arrived at Western Sydney University on 29 August 2024. Fruit with visible damage, bruising, cracking, decay or marked deformity were left out, and the rest were shared at random among the treatments.
The three kinds of packaging were:
- net bags on an open tray, standing in for the open packaging common in domestic retail (the control);
- perforated 125 g recycled polyethylene terephthalate (rPET) blueberry punnets, to see whether an existing retail pack could be reused for another fruit;
- moulded cardboard clamshell boxes with a clear window, chosen as an environmentally friendly, 100% recyclable and biodegradable option.
Each kind went into three storage conditions: a laboratory at 25 ± 2 °C and 90 ± 5% relative humidity (which the authors describe as ambient indoor temperature in Australia during the cropping season), a cool room at 8 °C, and a cool room at 4 °C to simulate refrigerated transport. Over eight weeks the team tracked weight loss, firmness, peel colour, chilling injury, fungal growth, shrivelling and saleability, plus three nutritional measures: total phenolic content, flavonoid content and antioxidant capacity.
What did they find?
- Room temperature was the worst place for them. Shrivelling showed up at room temperature in Week 1 (Week 2 in punnets), and fruit in every pack were unsaleable after about 10 days because of pronounced shrivelling and desiccation. By Week 8 these fruit were completely dry, with too little pulp or juice left to test.
- 4 °C kept the fruit firm and nutritious, but brought chilling injury. Fruit at 4 °C lost the least weight and kept firmness, colour, phenolics, flavonoids and antioxidant capacity best. However, chilling injury appeared by Week 3 in net bags and cardboard and Week 4 in punnets, reaching a moderate score of 2 on a 0 to 3 scale, and visible fungal growth followed a week later. About 20% of fruit in each pack were unsaleable by Week 8.
- 8 °C avoided the injuries, and the pack then decided freshness. At 8 °C there was no chilling injury, visible fungal growth or shrivelling. Even so, about 60% of fruit in cardboard clamshells and net bags were unsaleable at Week 8 because of loss of freshness (a decline in overall visual appeal without visible fungal growth, chilling injury or shrivelling), while about 80% of fruit in punnets stayed saleable.
- Punnets cut weight loss. At every temperature, fruit in the rPET punnets lost the least weight and fruit in net bags lost the most. The authors suggest less moisture moved between fruit and air inside the punnet, while net bags left the fruit exposed to moving air.
- Nutrients faded faster in the warmth. Between Weeks 2 and 6, flavonoid content fell by about 43 to 59% at room temperature and 28 to 36% at 8 °C, against only 14 to 15% at 4 °C. Fruit in punnets kept significantly more flavonoids than the other packs at each temperature.
- Cardboard clamshells did worse than punnets. The authors suggest this may be because cardboard can absorb moisture in humid conditions, which may allow more moisture exchange between the fruit and the air around it.
What could it mean?
The authors conclude that, under the conditions of their study, storage at 8 °C in rPET punnets gave the best balance between keeping quality and keeping fruit saleable. They call for further testing across cultivars, seasons and growing conditions, and suggest future work on edible coatings or natural anti-fungal treatments to cut chilling injury and fungal decay. The study aimed to identify the most favourable conditions for transporting and storing finger limes, so for now it is most useful to people who pack, transport or store the fruit commercially. The trial used laboratory and cool room conditions, not a household fridge.
What were the limitations?
- One cultivar, ‘Red Champagne’, from one harvest season was used, and the authors say further validation across cultivars, seasons and growing conditions is warranted.
- The authors note that using three replicate packages per treatment limits how far the findings can be generalised.
- Sensitivity to cold varies between citrus types, so the chilling response seen in ‘Red Champagne’ at 4 °C may differ in timing and severity from other cultivars.
- Individual phenolic profiling, and isolating and identifying the fungi, were beyond the scope of the study.
Trial details
- Where: fruit grown and commercially harvested by Lilyshire Finger Limes, Cardwell, QLD, Australia, and received at Western Sydney University on 29 August 2024. Storage in a laboratory and two cool rooms. The research team is from the School of Science, Western Sydney University, Hawkesbury Campus, Richmond, NSW (author affiliation).
- When: harvested 25 August 2024, received 29 August 2024, then stored for eight weeks. Measurements were weekly or fortnightly, depending on the measure.
- Crop: finger lime (Citrus australasica F.Muell.) ‘Red Champagne’, harvested fruit. The grower washed the fruit in 1% sodium hypochlorite solution for 1 to 2 min as routine postharvest treatment.
- Packaging: net bags on an open tray (control); perforated 125 g rPET blueberry punnets; moulded cardboard clamshell boxes with a transparent window.
- Storage conditions: room temperature, a laboratory at 25 ± 2 °C and 90 ± 5% relative humidity; a cool room at 8 °C; a cool room at 4 °C.
- Design: three packaging types by three temperatures. Three replicate packages per combination, each holding five numbered fruit; one fruit from each package was assessed at each sampling time (n = 3). Analysis of variance at each time point in Statistica (V14), arcsine transformation for percentages, means separated by Fisher’s LSD test at p = 0.05.
- Measures: weight loss (%); firmness by puncture test with a texture analyser (5 mm probe, 10 mm depth); peel colour by chromameter (L*, a*, b* and ΔE*); chilling injury on a 0 to 3 scale; visible fungal growth; shrivelling; saleability; total phenolic content (Folin-Ciocalteu method), total flavonoid content and antioxidant capacity (FRAP) in the pulp.
- Results: storage temperature and packaging both had highly significant effects (p < 0.001) for most variables and times, with significant temperature × packaging interactions for weight loss at all times, firmness at Weeks 4 and 8, flavonoids at Weeks 2 to 6 and antioxidant capacity at Week 8 (p < 0.01). First chilling injury: Week 3 (cardboard, net bag) and Week 4 (punnet) at 4 °C, none at room temperature or 8 °C. First visible fungal growth: Week 4 (cardboard, net bag) and Week 5 (punnet) at 4 °C, none elsewhere. Unsaleable at Week 8: 100% at room temperature in all packs; about 60% (cardboard, net bag) and about 20% (punnet) at 8 °C; about 20% in all packs at 4 °C. Flavonoid loss from Weeks 2 to 6: about 43 to 59% at room temperature, 28 to 36% at 8 °C, 14 to 15% at 4 °C.
- Funding and conflicts of interest: Future Food Systems Cooperative Research Centre (grant P2-042) and an Australian Government Research Training Program Scholarship to the first author. The authors declare no conflicts of interest.
- Publication: Foods 15(19), 3476, published 28 September 2026, https://doi.org/10.3390/foods15193476. Licence: CC BY 4.0.
- Not reported in the paper: the relative humidity in the 8 °C and 4 °C cool rooms, how the trees were grown in the orchard, and the fruit’s maturity stage at harvest.
Links
- The study: Effects of Storage Temperature and Packaging Type on the Postharvest Quality of Finger Lime (Citrus australasica)
- The institution: School of Science, Western Sydney University
References
- Noeparast, H., Panchal, S. K., Holford, P., & Donovan-Mak, M. (2026). Effects of storage temperature and packaging type on the postharvest quality of finger lime (Citrus australasica). Foods, 15(19), 3476. https://doi.org/10.3390/foods15193476