Packhouse practices for papaya

Transport fruit promptly from field to packhouse and use shaded and sanitized vehicles that are designated for food to minimize contamination and heat exposure. Transport during cooler hours or in refrigerated trucks. Once the fruit arrives at the packhouse, weight is recorded, together with quality checks and labelling for proper traceability. Fruit should be processed as quickly as possible, at target temperature (dependent on ripeness/type and storage period), in a clean, disinfected space.

During papaya harvest, it is critical to prevent and remove latex contamination to avoid black spot formation and decay. Essential postharvest treatments include sanitation and fungicide application to protect against common diseases, such as Colletotrichum and Alternaria, which often emerge during storage.

After harvest, papaya is sorted by size and color. Damaged or substandard fruit is discarded. The remaining high-quality fruits, which should be firm, smooth, and well-formed, undergo washing and fungicide treatment. They are then dried, graded, and packed. Before shipment, a pre-cooling step improves storability. In addition, quality inspections including maximum residue level (MRL) testing are conducted. To maintain quality, especially for export, fruit must be cooled within 10 hours of harvest and before being placed in shipping containers.

Papaya is very sensitive to mechanical damage due to its thin skin and soft flesh. Packaging should protect the fruit adequately. Packing materials should be clean and of sufficient quality to prevent damage.

To protect the fruit, individual fruit is put in polypropylene bags, nets or corrugated board before being placed into distribution boxes. Distribution boxes are typically made of corrugated board, holding 6-12 fruits based on variety and market.

Labelling begins upon arrival at the packhouse. Fruit from incoming crates are sampled for quality and assigned a class category. This informs growers of the fruit's quality and assigns a label for identification at each stage in the chain. Commercial decisions consider these quality parameters and are tailored to market requirements. Each shipment pallet is specifically labelled for tracking purposes.

Cooling papaya post-harvest is crucial to keep the fruit metabolism low. Precooling is advisable for papaya, with hydrocooling as an option. However, rapid cooling can cause chilling issues. When storing fruit at too low temperatures, chilling will limit storage-life, while at somewhat higher temperatures, ripening begins slowly. The ideal cooling temperature lies in the range of 7-13°C, depending amongst others on fruit ripeness and duration of exposure, with colder temperatures for mature and warmer for green fruit. Furthermore, keep papayas at 90-95 % relative humidity to prevent water loss.

Maintaining cleanliness throughout the supply chain is crucial. Next to the procedures for handling of the fruit, it is important to clean and sanitize all equipment and tools daily, and to remove soil and organic materials prior to sanitation.