Packhouse practices for bananas
Packhouse practices include the activities from the moment the products arrive at the collection station or packhouse to the moment of transport to the intended market. Dividing the bunch into smaller units, washing, sorting and packing are among the main activities. Good packaging is a requirement to maintain a good quality of banana throughout the rest of the supply chain. This also applies to good temperature management. Furthermore, proper cleaning and sanitizing of building and equipment is part of good packhouse practices.
Well regulated and controlled processes
The activities at the packhouse must be well regulated and controlled. The process of washing, cutting, grading and packing is always well supervised. The skin is vulnerable to damages. Always handle bananas carefully. Packing in cardboard boxes with bags is done in such a way that it provides a high humidity and a good protection against abrasion damage during transport. Bananas should be rapidly cooled after harvest. However, bananas should not be stored below their critical temperature, as chilling injury may then occur which would result in risks on discolorations of skin, poor flavour and increased susceptibility to decay.
Before packing the bananas
Bananas in the packhouse. Photo by Salvador Aznar/Shutterstock.com
Receipt and unloadingWhen the bananas arrive from the field, the packhouse activities should begin immediately in order not to delay processing and the beginning of cooling. A first quality control can take place simultaneously with unloading. Length and diameter of bananas are checked. In this process, it is important which hand to choose, because the maturity of hands varies within a complete bunch. A quality supervisor registers the data.
Washing of bananas. Photo by barmalini/Shutterstock.com
Cleaning and washingCleaning the bananas is important to remove surface dirt, latex stains or pathogens. Harvested heavy bunches are divided into smaller market-friendly clusters of bananas. The hands cut from the stem are placed in a water bath to remove latex. To avoid infestation with pathogens in the dump tank, the water must be sanitized. The fresh wound on the crown is treated to control crown rot.
Grading bananas. Photo by Salvador Aznar/Shutterstock.com
Grading and classificationGrading and classification should result in uniformity in size and quality. The minimum acceptable size (length, diameter) depends on market specifications. Bananas that do not meet the desired fresh market specifications can be used for processed products. Bananas are classified into classes such as: Class Extra, I and II. Examples of minimum requirements are that fruits must be intact, sound, clean, firm, free of damage caused by low temperatures, and with the stalk intact.
Activities at packhouse from packing onwards
Box used to pack bananas. Photo by WUR.
Packing in boxesThe use of perforated boxes, pads and foil makes it possible to later ripen bananas with ethylene while they are still in the boxes. A linerbag is added according to the bag-in-box principle. Bananas are carefully laid in the box. Paper pads are used at the bottom and between layers of bananas to reduce abrasion damage. The exact packaging requirements differ between customers. Boxes for transport usually contain 18 kg of bananas.
Example of a liner bag. Photo by WUR.
Liner bagsBananas are usually packed in polyethylene bags in boxes. Bags that are widely used are Polypack (or polybag) and Banavac. Polypack is a perforated bag that reduces water loss and protects fruits from abrasion damage. In Banavac packaging, the air is extracted, using a “vacuum cleaner”. In this bag, O2 is reduced and CO2 increases which delays the ripening.
Banana box with label information about class, type, minimum length and weight. Photo by WUR.
Labelling and palletizingThe boxes must be stacked on a pallet and labelled with information including packhouse code, size/class, and batch number. Further the name of the fruit (banana) + variety, and net weight must be on each box. Completed pallets must be strapped well so that boxes cannot shift or fall. The use of corner boards makes pallets more stable. As soon as pallets are completed, they can be moved to the cold storage.
Example of a forced air pre-cooling installation. Photo by WFBR.
CoolingA fast temperature reduction is necessary to remove field heat from the bananas as soon as possible, to avoid premature ripening. It extends the storage life of the banana and inhibits the growth of moulds. Forced-air cooling is an effective tool. During this cooling process, the fruit pulp temperature should be regularly checked in the coldest and warmest place of the pile.
Stacks of banana boxes in storage. Photo by AleksSafronov/Shutterstock.com
StorageBananas are usually not stored at the packhouse, but shipped as soon as possible. Bananas (Cavendish) can be stored and transported in the green stage for several weeks at a temperature of 13.3 – 14.0 °C. The storage time is extended a few weeks by Modified Atmosphere (MA) in “Banavac” or under Controlled Atmosphere (CA). The optimum atmosphere is in the range 2-5% O2 and 2-5% CO2. The optimum humidity around the bananas is 90-95%. .
Good cleaning of equipment and materials 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. Machinery 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.