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Pre-sizing and Packing

Tree fruit is harvested, placed undercover or in the shade, and then transported to packinghouses as soon as possible after harvest. Apples and pears are cooled as soon as they reach the warehouse to remove the field heat, and cherries are often hydro-cooled in the field before transport, because they start to lose quality as soon as they are picked, and heat exacerbates this. Fruit are sampled, washed, sorted, graded, packed, and stored after arriving at the packinghouse. The variety of fruit, time of harvest, and fruit quality determine the packing and storage protocols that will be used.

Apples are checked for fruit quality when they arrive at the packinghouse, then possibly drenched with fungicides, depending on whether they are Organic or Conventional, and placed in cold storage. Apples are then packed with the Direct Pack or Presize systems. See the apple section below for apple packing steps.

Pears are packed right after harvest, or stored in controlled atmosphere (CA) storage. Pears require “conditioning” in cold storage for a certain length of time in order to ripen properly when consumers purchase them. They are not presized due to their delicate skin, and will not tolerate the extra handling. See the pear section below to learn more.

Sweet Cherries arrive at the packinghouse, and are placed in cold storage immediately. Cherries are then sorted, sized, and packed in a short amount of time due to their shorter storage and shelf life. They can be in cold storage for a couple of months, but are sold as soon as possible after harvest. See the cherry section below for more information on packing cherries.

Apple

There are two main types of packing systems, Commit to Pack (AKA direct pack) and Presizing. For the Commit to Pack system, the warehouse contracts with the grower that they will pack their fruit at the time that the bins are first emptied. A disadvantage of this system is that if the packed fruit is not sold at that time, it will be returned to storage and it may have to be unpacked and sold for processing if there is no order placed for that fruit. For the Presizing system, once fruit are sorted for various sizes, they are returned to bins and placed back into storage until there is a need for that fruit. Presized fruit bins are often made up of pooled grower lots. This may require extra record keeping to maintain the food safety traceability of each grower lot within the pool. Note that apples are generally less sensitive to packing injury than pears (noted below) and can withstand the extra pre-sizing process.

Apples from field bins are dumped into the water tank: the first step in the packing and sorting process.
Granny Smith apples floating from the dump tack to the conveyors. (W.E. Jones-WSU)

Regardless of the packing system, the basic steps are the same. First, apples are brought out of regular or Controlled Atmosphere (CA) storage when it is time to pack or presize. If the facility uses hydro handling, bins of apples are immersed into a water dunk tank where fruit float out to a conveyor belt. If the facility uses dry loading, full bins are tipped directly onto the conveyor belt. The apples are then moved to the sorting lines, where trained personnel remove and discard the decayed (if they haven’t already been removed), defective, damaged, and undersized fruit. These are referred to as culls. Insect stings, decay, and severe sunburn are all considered culls (learn more). Very small fruit are separated out for disposal or possibly for processing. Apples then proceed to cleaning (soaking in water containing food-grade detergents and disinfectants), rinsing with water and air-drying.

Packing lines vary in the types and amounts of chemicals used in the packing process (learn more). Certain varieties are sprayed with food grade wax to help prevent moisture loss, slow down respiration in storage, and to increase shine. Organic apples are not waxed and undergo a slightly different process (learn more here and here).  Fruit is then graded and sized by hand or by using automated optical technology. There are national and state standards for apple grades. Grades consist of appearance, color, size, weight, and internal quality. Some varieties may have various shades of color, all with several grades and sizes. Computer controlled automated sorters are used by many facilities to analyze apple size, color and even internal quality (learn more). After sorting and grading fruit for the Presizing system they are returned to bins labeled specifically for their grade and size then placed back into cold storage until needed to fill an order. Commit to pack fruit proceed directly to the packing area.

Fruit to be packed are sent via conveyor belts to the packing area. Along the way, individual fruit are labeled by machine. The fruit are then placed in trays or bags either by hand or by a packing robot then loaded into boxes. Apples are commonly boxed by size. For example, seventy-two size 72 apples fit in a 42-pound carton. Full containers are labeled with information about variety, size, grade, grower lot number and facility for food safety and traceability.  Containers are weighed and placed on pallets and then moved to the shipping area for loading or returned to cold storage if not being shipped right away.

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Pear

Pears are either packed right after harvest, or are stored in Controlled Atmosphere (CA) storage. Pears are mature, but not yet ripe when harvested, and must undergo a ripening process called conditioning before they are packed so that they will ripen properly when consumers buy them.  Pears are not pre-sized prior to packing due to their thin, delicate skin that bruises easily. At the time of packing, fruit are gently dumped out of bins onto the packing line. Fruit are rinsed, washed with food-grade detergent, and rinsed again. Next, they are run over a bed of brushes and fans, to dry completely. Trained personnel hand sort the fruit, removing any defective or decayed fruit from the line.  Pears can also be sized and sorted with computer technology. Labels are placed on the fruit, indicating the grade, variety, and size, and then they are packed into boxes. This is done by hand and with automation.  Boxes are palletized and put back into cold rooms where they wait for shipment.

Related Links

Pear Handling Manual, An excellent resource from the Pear Bureau Northwest.  (Accessed: 1/19/17).

Cherry

Cherries do not contain stored carbohydrates like apples and pears, therefore have a shorter storage and shelf life, but good fruit quality can be maintained in cold storage for a couple of months. Cherries are difficult to handle because they are very susceptible to bruising (pitting), and extra care is taken on the packing line to eliminate mechanical injuries. Packers refer to a “cold-chain,” which signifies keeping cherries cool during the whole process chain (harvest through the packing process, shipping, retail markets, and until they are consumed.) To start the packing process, cherries float onto the packing line on flumes of water, which protect them from bruising and damage.  Orchard debris and leaves are removed from the flumes with nets. The cherries go through a cluster cutter to cut stems of clusters into single fruit with shorter stems.  Fruit is sorted and sized, either manually by trained personnel, or electronically, with a computer.  With the computer sorter, multiple images of each cherry are taken, analyzed, and fruit are automatically sorted and sized. Fruit that were singled out are sorted again by hand for culls.  Some operations hydro-cool fruit before packing to maintain fruit quality. Cherries are packed into a variety of boxes, clamshells, and bags by size and weight. Cartons are then labeled, palletized, shrink-wrapped and sent to cold storage or refrigerated trucks for shipping.

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