Post-Harvest Handling and Storage of Apples and Pears

Every apple or pear that reaches the market in perfect condition is the result of a carefully managed chain of operations that begins the moment it leaves the tree. Post-harvest losses in fruits can be staggering – fruits and vegetables account for 40-50% of food losses globally, with much of this occurring in the post-harvest stage. For apples and pears specifically, the difference between a profitable harvest and significant economic loss often comes down to how well three steps are executed: pre-cooling, grading, and storage. Getting these right not only preserves fruit quality but also opens the door to additional revenue through value-added processing.

Why post-harvest management matters for apples and pears 🔗

Apples and pears are living organisms. Even after they’re picked, they continue to respire – consuming their own sugars and releasing carbon dioxide and heat. This metabolic activity, if not managed, rapidly degrades firmness, flavor, and appearance. Once harvested, apples need to be pre-cooled immediately to minimize the field heat carried by the fruit itself, as delays directly shorten marketable shelf life. The goal of post-harvest management is to slow this biological clock as much as possible – keeping the fruit in a near-dormant state from harvest to consumer.

Pre-cooling: the first and most critical step 🔗

Field heat is the thermal energy accumulated by fruit during growth and harvest. Removing it quickly is essential. A delay of just one day in the orchard at 21°C after harvest can shorten storage life by 7 to 10 days at 0°C. A three-day delay in a warm packing shed can reduce storage life by 30 days – even if the fruit is later placed in a controlled atmosphere.

Several pre-cooling methods are used depending on the facility and volume:

Room cooling 🔗

The simplest and least expensive method involves stacking bulk boxes in a refrigerated room and allowing the cold air to gradually lower fruit temperature. While cost-effective, it is the slowest of the common methods and can lead to uneven cooling in large loads.

Forced-air cooling 🔗

This method blows refrigerated air directly across the fruit by creating a pressure differential between two sides of a stack. Pre-cooling with forced air is considered a compulsory step in developed countries and is significantly faster than room cooling. It is the preferred method for large commercial operations.

Hydro-cooling 🔗

Hydro-cooling involves immersing or spraying fruit with cold water. Water transfers heat far more efficiently than air, making this method very rapid. However, it requires that fruit surfaces be dried before grading and packing to prevent fungal issues.

Regardless of method, modern cooling is typically a dynamic process: initial removal of field heat, followed by a gradual, stepwise reduction to the final storage temperature. Rapid cooling that is too aggressive can exacerbate certain storage disorders and extract excess moisture from the fruit, reducing packout quality.

Grading: sorting for market and value 🔗

Once pre-cooled, fruits are graded to separate them by quality and size. Grading serves two purposes: it ensures that consumers receive a consistent, expected product, and it routes lower-quality fruit to appropriate channels – fresh market, processing, or waste reduction – before the entire lot is compromised.

Size grading 🔗

Apples are sorted manually or mechanically into six different size categories. Typical classifications include small (under 65mm diameter), medium (65-75mm), large (75-85mm), and extra-large (over 85mm). Pears follow similar size classifications, though exact thresholds may vary by variety. Size grading for pears is generally performed mechanically, and fruits are then packed in pre-formed mouldings to prevent bruising during transport.

Quality grading 🔗

Apples are also evaluated for color, shape, and overall appearance and assigned quality grades such as AAA, AA, A; or Extra Fancy, Fancy Class I, and Fancy Class II. Visual inspection – whether by trained workers or automated optical systems – identifies color uniformity, surface blemishes, bruises, and physiological disorders. Premium-grade fruits are directed to fresh markets, while those with minor cosmetic defects are channeled into processing. Severely damaged fruits are removed immediately to prevent triggering ripening in nearby healthy fruit through ethylene gas release.

It is worth noting that quality control in apple grading has historically been plagued by subjectivity and inconsistency, with orchard managers relying on manual tools like ring sizers to assess only a small fraction of the harvest. Advances in optical sorting and digital monitoring are helping to standardize this process at scale.

Cold storage: creating the right environment 🔗

After grading, fruit destined for the fresh market enters cold storage. The conditions maintained in the storage room directly determine how long the fruit remains marketable.

Temperature 🔗

Most apple varieties are best stored at temperatures between -1.1 and 0°C (30-32°F). This narrow range sits just above the fruit’s freezing point – cold enough to dramatically slow metabolic processes, but not so cold as to cause internal browning or tissue damage. However, chilling-sensitive varieties like Golden Delicious and Granny Smith may require slightly warmer storage of 3.3-4.4°C to avoid chilling injury. European pears are generally not chilling-sensitive and most cultivars can be stored between -1 and 0°C, although they typically require a brief chilling period to stimulate ethylene production and proper ripening after removal from storage.

Relative humidity 🔗

Preharvest and postharvest factors such as storage temperature, relative humidity, storage type, and duration all affect water loss in apple fruit during storage. Relative humidity (RH) in storage rooms should be maintained at 80-90%. Apples contain around 84% moisture at harvest, and without adequate humidity, skin shriveling and weight loss follow. A humidification system is installed specifically for maintaining humidity levels in commercial cold stores. Polyethylene liners and film wrapping of bins can also help retain moisture around more susceptible varieties.

Shelf life under cold storage 🔗

Under optimal cold storage conditions, apples can remain marketable for 4 to 6 months, while pears typically hold quality for 2 to 4 months. Storage duration varies considerably by variety: winter pear varieties like Anjou can be stored in controlled atmosphere at -1°C for up to 6 months, while summer varieties like Bartlett are far more perishable. Among apples, varieties like Rome ripen slowly at 0°C and store for longer periods, while McIntosh ripens quickly and has a shorter storage life.

Controlled atmosphere storage: extending shelf life further 🔗

Conventional cold storage controls only temperature and humidity. Controlled atmosphere (CA) storage goes further by also regulating the levels of oxygen, carbon dioxide, and ethylene inside the storage room. In CA storage, apples are sealed in an environment of around 2% oxygen, compared to the 21% in normal air, with temperature, humidity, nitrogen, and carbon dioxide all carefully regulated. The severely reduced oxygen environment essentially makes the fruit dormant, dramatically slowing ripening.

At the commercial level, CA is most widely applied during the storage and transport of apples and pears, and under these conditions some apple varieties can remain marketable for up to 10 months. Ethylene management is also critical in CA storage – ethylene is periodically removed from the room by flushing with nitrogen, burning it off, or using specialist ethylene scrubbers to prevent the gas from accelerating ripening across the entire stored batch.

Common cold storage disorders to watch for 🔗

Even with correct temperatures and humidity, biological disorders can arise during storage. The four most common cold storage disorders in apples and pears are superficial scald, water core, bitter pit, and internal browning. Critically, many of these disorders have roots in pre-harvest orchard management – meaning that post-harvest interventions alone cannot fully prevent them. Superficial scald, for instance, is the most common and can be mitigated by diphenylamine (DPA) dip treatments applied after harvest. Bitter pit, linked to low calcium levels in the fruit, can be reduced with calcium chloride spray treatments before storage.

Turning rejected fruit into value: processing options 🔗

Not all harvested fruit makes it to the fresh market. Fruits with minor cosmetic defects, bruising, or early-stage disorders that cannot be stored can still generate significant revenue through processing. This reduces post-harvest waste and improves the overall profitability of the operation.

Pulp and purée 🔗

Apple pulp, produced by washing, cooking, and pureeing the fruit, forms the base for applesauce, baby food, and bakery ingredients. Pear pulp is similarly used in desserts, smoothies, and health food products. Apple by-products are rich in sugars, proteins, dietary fibers, and phenolic compounds, meaning that processed pulp retains genuine nutritional value rather than being a nutritionally empty byproduct.

Jams and preserves 🔗

Jams and preserves are a particularly effective outlet for lower-grade fruit because the cooking process neutralizes concerns about cosmetic defects while creating a product with a long shelf life and strong market value. Apple pomace is a natural source of pectin, a gelling agent widely used in jams, jellies, and other food formulations. Small-scale processors frequently find niche markets for artisanal or organic varieties of these products.

Juice production 🔗

Around 25% of apples are turned into processed products, with juice being the most sought-after. Modern juice extraction systems can process fruit with minor defects efficiently, making juice production the largest-volume processing option available to growers. Pear juice, while a smaller market, is similarly produced and can command premium pricing when marketed as artisanal or single-variety.

Beyond the basics: emerging value-added uses 🔗

Apple pomace has been valorized through pectin extraction for use as a gelling agent in jams and jellies, incorporated into cereal-based products like cookies and bread to enrich dietary fiber content, and subjected to fermentation processes for the production of vinegar. The extraction of phytochemicals and recovery of dietary fiber from fruit pomace are promising ways to efficiently use these by-products across the food, pharmaceutical, and cosmetic sectors. For growers and processors already investing in juice or pulp lines, these downstream applications represent additional revenue streams from material that would otherwise be discarded.

The economics of getting post-harvest right 🔗

Effective post-harvest management is ultimately an investment in protecting the value already created in the orchard. The cost of cold storage infrastructure, CA systems, and grading equipment is real, but so is the cost of losses. With the right storage conditions and CA facilities, farmers and producers can not only maximize profits but also ensure customer satisfaction with quality produce. For smaller operations without access to CA technology, even well-managed conventional cold storage at the correct temperature and humidity – combined with a processing outlet for rejected fruit – can substantially reduce losses and improve margins. The key is treating every step from harvest to storage as part of a continuous quality management system, rather than a series of isolated tasks.

What do you think? With CA storage extending apple shelf life to nearly a year, how should small-scale growers without access to this technology compete in markets that increasingly expect year-round supply? And as processing technology makes it easier to extract value from rejected fruit, at what point does investing in on-farm processing become more profitable than selling to third-party processors?

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC8891749/
2. https://link.springer.com/article/10.1007/s11947-023-03305-9
3. https://content.ces.ncsu.edu/postharvest-cooling-and-handling-of-apples
4. https://felixinstruments.com/blog/how-to-improve-post-harvest-quality-in-fresh-produce/
5. https://apal.org.au/wp-content/uploads/2019/09/Post-harvest-management-Part-1.pdf
6. https://www.bighaat.com/kisan-vedika/blogs/post-harvest-management-for-apples
7. https://www.cargohandbook.com/Pears
8. https://www.croptracker.com/blog/apples-and-postharvest-handling-all-about-ca-storage.html
9. https://rinac.com/blog/cold-storage-for-apples-and-how-does-it-work/
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC9914392/
11. https://www.fao.org/4/y5431e/y5431e06.htm
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC12154521/
13. https://www.sciencedirect.com/science/article/pii/S0963996925014875
14. https://www.explore-leap.com/post/from-landfill-to-leather-alternative-the-apple-waste
15. https://www.mdpi.com/2071-1050/16/16/7001