Storage Practices to Extend Shelf Life of Litchi and Jamun

Litchi (Litchi chinensis Sonn.) and jamun (Syzygium cumini L.) are two beloved subtropical fruits with one shared problem: they both start deteriorating almost as soon as they are picked. Litchi is a non-climacteric fruit that is harvested only at full maturity, after which its shelf life at room temperature is generally less than 72 hours. Jamun fares no better – it can only be stored for 2-3 days under ambient conditions before it begins to deteriorate. Given these realities, understanding correct storage practices is not just academic – it directly affects how much of the harvest actually reaches consumers in acceptable condition.

Why litchi and jamun spoil so fast 🔗

Both fruits are highly sensitive to moisture loss and microbial activity after harvest. In litchi, the most visible sign of deterioration is pericarp browning – the bright red outer skin turns dull and brown, making the fruit commercially unattractive even if the flesh inside is still edible. This browning is linked to the loss of cellular compartmentalization, where oxidative enzymes come into contact with phenolic substrates and produce brown-colored compounds. Desiccation from low humidity accelerates this process significantly. In jamun, the challenge is rapid softening, decay, and weight loss, all of which are driven by enzymatic activity and microbial spoilage after harvest.

Post-harvest challenges in litchi include micro-cracking of the pericarp, dehydration, and fungal decay – all of which can be aggravated by poor handling during the cold chain. For jamun, the fruit has a very short postharvest life at ambient temperatures, though storage life can be extended with the use of appropriate treatments such as refrigeration. Understanding both fruits’ vulnerabilities is the first step toward managing them well.

Cold storage: the primary line of defence 🔗

Lowering temperature is the most effective and widely adopted method for extending the shelf life of both litchi and jamun. Cold conditions slow down metabolic processes, respiration rates, and microbial growth – all of which drive spoilage.

Litchi cold storage requirements 🔗

For litchi, the recommended storage temperature is between 0°C and 3.3°C, paired with high relative humidity of 90-95%. At 3-5°C, litchi can achieve a storage life of around 30 days. Humidity management is equally critical. Modified atmosphere packaging maintains higher relative humidity around the fruit, which helps prevent enzymatic browning and inhibits microbial spoilage during postharvest storage.

However, how long you store litchi in cold conditions matters as much as the temperature itself. No pericarp browning was evident in litchi fruit stored for 10 and 20 days at 3-5°C at the point of removal, but fruit stored for 30 days had a decay incidence of about 30% after just 24 hours on the shelf at ambient temperature. This means that even well-stored litchi degrades rapidly once it is moved back to room temperature – a key consideration for the supply chain.

Jamun cold storage requirements 🔗

Jamun benefits from cold storage in a similar way. Research has shown that jamun stored under modified atmosphere conditions at 5°C and 75% relative humidity can remain acceptable for up to 23 days. Under optimal cold storage with proper packaging, jamun can last up to three weeks – a dramatic improvement over its 2-3 day ambient shelf life. Cold storage slows down microbial growth and the enzymatic reactions that cause spoilage in jamun.

Packaging: sealing in freshness 🔗

Cold storage alone is not sufficient. The type of packaging used has a direct impact on how well both fruits hold up during storage and transport. Packaging controls the immediate micro-environment around the fruit – humidity, gas composition, and physical protection.

Polyethylene bags for litchi 🔗

Polyethylene bags are among the most commonly used packaging materials for litchi. Litchi stored in non-perforated polyethylene bags wrapped with browning paper at 5°C with 95% relative humidity showed significantly delayed pericarp browning, reduced weight loss and decay, increased firmness, and retained color and nutrition during storage. Perforated bags are also used, though the perforation size must be carefully chosen to balance gas exchange with moisture retention.

Modified atmosphere packaging (MAP) 🔗

Modified atmosphere packaging (MAP) is a step up from simple polyethylene bags. It involves sealing produce in packaging that alters the gas composition around the fruit – typically reducing oxygen and increasing carbon dioxide – to slow respiration and delay senescence. Litchi fruits stored under MAP showed reduced decay, a lower browning index, and less fresh weight loss, while also retaining higher levels of total soluble solids, ascorbic acid, and antioxidant activity.

For jamun, MAP has also demonstrated significant benefits. Modified atmosphere packaging has been found effective in increasing jamun’s shelf life by up to 30 days when applied correctly. The packaging slows down the biochemical changes that accompany ripening and senescence, buying additional time without resorting to chemical treatments.

Postharvest treatments that complement storage 🔗

Beyond temperature and packaging, several pre-storage and post-harvest treatments have been shown to enhance the shelf life of both fruits. These are applied before placing the fruit in cold storage and work synergistically with the cold chain.

Treatments for litchi 🔗

Sulfur dioxide (SO₂) fumigation has historically been the most widely used treatment for controlling litchi browning during export. However, it is increasingly restricted due to health concerns and chemical residues. Alternative treatments that avoid SO₂ include hot water brushing combined with acid dipping, melatonin application, and modified atmosphere packaging.

Research published in the Journal of Food Chemistry & Nanotechnology found that litchi treated with hot water treatment (55°C for 12 minutes) followed by nitric acid and calcium chloride dipping, and then stored under cold conditions at 4-5°C, remained acceptable even after 28 days of storage. Precooling immediately after harvest also helps remove field heat before the fruit enters long-term cold storage.

Treatments for jamun 🔗

For jamun, edible coatings have emerged as a practical and food-safe method to extend shelf life. Zein-based coatings enriched with ascorbic acid and jamun leaf extract improved antioxidant activity and delayed softening and decay in stored jamun fruit. Chitosan coatings are also effective – chitosan at 1.5% concentration was found to record the lowest decay incidence and extend jamun shelf life to nearly 15 days under refrigerated conditions. These coatings reduce moisture loss and slow enzymatic browning without any chemical toxicity concerns.

Handling practices throughout the cold chain 🔗

Even the best storage conditions can be undone by rough or careless handling at any stage of the supply chain. For both litchi and jamun, physical damage during harvesting, sorting, packing, or transportation creates entry points for microbial decay and triggers the very browning and deterioration that storage is designed to prevent.

Incorrect postharvest handling practices during the cold chain can accelerate desiccation and moisture loss, which lead to intensive pericarp browning in litchi. Key best practices include harvesting at the correct stage of maturity, using clean and sanitized tools to minimize microbial contamination, handling fruit gently to avoid bruising, and moving fruit into cold storage as quickly as possible after harvest to remove field heat. Refrigerated vehicles should be used for transport to maintain the cold chain without interruption. Even short-term temperature fluctuations during shipping, handling, or retail display can negatively affect the quality of cold-stored litchi.

A note on ambient storage limitations 🔗

Where cold chain infrastructure is unavailable or too costly – which remains a reality in many litchi- and jamun-producing regions – ambient storage offers very limited options. Under ambient conditions, the shelf life of litchi fruit is approximately 4-6 days, and once removed from cold storage, litchi transferred to room temperature has a remaining shelf life of only 1-2 days. For jamun, ambient storage similarly results in decay within 2-3 days. This underscores why investment in cold chain development, even at the small-scale farm level, is directly tied to reducing post-harvest losses for both crops. Post-harvest litchi losses are estimated at 25-30% or even higher in some growing areas, much of which is attributable to gaps in cold chain access.

What do you think? Given that both litchi and jamun have such a short window between harvest and spoilage, how feasible is it for small-scale farmers in India to invest in cold storage infrastructure – and what practical, low-cost alternatives might help bridge that gap? If MAP and edible coatings can extend jamun’s shelf life from 2 days to nearly 3 weeks, why do you think this fruit remains so underutilized in the commercial market?

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC6994857/
2. https://link.springer.com/article/10.1007/s11738-019-2884-z
3. https://www.sciencedirect.com/science/article/abs/pii/S0925521410002632
4. https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119750802.ch5
5. https://www.mdpi.com/2311-7524/9/6/651
6. https://link.springer.com/article/10.1007/s13197-011-0254-y
7. https://scialert.net/fulltext/?doi=ajft.2017.322.331
8. https://www.sciencedirect.com/science/article/abs/pii/S030442381930319X
9. https://www.pshsciences.org/publications/jhst/issues/4-3/2021-109/
10. https://acsess.onlinelibrary.wiley.com/doi/10.1002/csc2.21274?af=R
11. https://foodchemistryjournal.com/2024/03/15/different-postharvest-treatments-and-storage-conditions-for-shelf-life-enhancement-and-quality-retention-of-litchi/
12. https://link.springer.com/article/10.1007/s11947-015-1577-x
13. https://plantarchives.org/article/283-%20Effect%20of%20postharvest%20treatments%20on%20shelf%20life%20and%20quality%20of%20jamun%20(Syzygium%20cumini%20L.%20Skeels)%20fruits.pdf
14. https://www.sciencedirect.com/science/article/abs/pii/S0925521406000883
15. https://www.nature.com/articles/srep19356
16. https://www.sciencedirect.com/science/article/abs/pii/S092552141200083X