Packhouse practices for strawberry
Packhouse practices cover the activities from the moment the strawberries arrive in the packhouse to the moment of transport to the intended market. Sorting, grading, packing and cooling are among the main activities. It is very important that the packhouse has sufficient capacity to cool the strawberries, as good temperature management is a requirement to maintain a good quality of horticultural produce. Furthermore, proper cleaning and sanitizing of building and equipment is part of good packhouse practices.
Maintain the cold chain
Strawberries can already be packed in the field or farm, or else in a nearby central packhouse. In any case, keep in mind that the strawberries must be subjected to (forced air) cooling as soon as possible. Rapid removal of field heat is essential for strawberries, so a location with a cooling facility should be near the production fields. Strawberries are delicate products and easily damaged. Escpecially for strawberries, it is therefore of utmost importance to have a careful handling in the packhouse to deliver a high quality product.
Packhouse points of attention
Truck with strawberries. Photo by WFBR
Receipt and unloadingWhen the strawberries arrive (from the field), unloading should begin immediately in order not to delay the further processing and the start of cooling. A first quality control can take place simultaneously with unloading. Further processing should also begin immediately (on a first-come first-served basis).
Packaging provides physical protection for strawberries. Photo by RomboStudio/Shutterstock.com
PackingStrawberries are highly sensitive to compression and vibration damage and very susceptible to water loss. The packaging must provide physical protection to these fruits. For this purpsose, punnets (primary packaging) are often used which are placed in cartons or crates. The bottom of the punnets can be padded with bubble wrap to minimize vibrational damages. Never use force! Not when filling the punnet or when placing the punnets in the carton.
Strawberries in a crate. Photo by cornfield/Shutterstock.com
Labelling and palletizingFilled packages must be stacked on a pallet and labelled with information including packhouse code, size/class, batch number, country of origin, and grower. Further the name of the fruit (strawberry) + variety, and net weight must be on each box label. The exact requirements can differ depending on local regulations and client demands. The completed pallets must be strapped well in such a way that the packaging cannot shift or fall. Often cardboard edge protectors are used to stabilize pallets. As soon as pallets are completed, they need to be moved to the cold storage.
Pre-cooling of strawberry. Photo by WFBR
Pre-cooling before storage of shipmentA fast temperature reduction by means of forced air cooling is necessary to remove field heat as quickly as possible. Strawberry is not sensitive to chilling temperatures and should be stored as cold as possible without freezing. This means a rapid reduction of the temperature (via forced air cooling) to 1°C or further down to 0 °C. During this pre-cooling process, the fruit temperature should be checked regularly in the interior of the boxes, at the coldest and warmest spot of the pallet.
Strawberries have a limited shelf life. Photo by RussieseO/Shutterstock.com
StorageThe storage time should be kept to a minimum, as strawberries are highly perishable. They can be stored for up to 1 week, but suboptimal temperature and disease pressure can significantly reduce this period. Check the quality in the storage room regularly. Strawberries should not be cooled to temperatures lower than 0.0 °C to prevent damage. That is why it is important to regularly check also the fruit temperature. A relative humidity of 90-95% can further help to preserve quality. Controlled Atmosphere storage (CA) or Modified Atmosphere Packaging (MAP) is possible in combination with low temperature.
Good cleaning of equipment and material is paramount. Photo by Sorn340 Studio Images/Shutterstock.com
Cleaning and maintenanceProper cleaning and sanitizing of building and equipment is part of good packhouse practice. Besides maintenance as prescribed by the supplier, a good cleaning and sanitizing of equipment such as the grading line is necessary prior to use. Sorting belts must be clean and have smooth surfaces. All surfaces that could lead to bruising or puncturing of fruit should be well covered for example with impact absorbing foam.