In-feed Blower Conveyors: This piece of equipment is were the blueberries enter our packing line. It consists of a variable speed conveyor belt and a fan system that blows air through the blueberries to remove any leaves, sticks or small under-formed fruit. The variable speed lets us control how fast we sort through the fruit, letting us maintain the required quality.
Soft-Sorters: These are pieces of equipment designed to remove soft or damaged blueberries. We use different kinds of soft-sorters, one uses an arrangement of sensor pads, another lasers, and still another uses coloration and real-time pictures of the fruit to determine how firm or soft a berry is. They all then use air-jets to remove fruit that is determined to be too soft, rejecting it from the main flow of fruit.
Color-Sorters: These machine use cameras to look at the fruit as it passes through the machine, helping to remove under-ripe and off-colored berries. There are different technologies for color-sorters. Some look at the chlorophyll in the fruit. Ripe fruit has less chlorophyll than under-ripe fruit. Others look at the actual color of the fruit and compare it to what we have selected as "good" or "bad" colors. Using LED light, others actually look just under the skin of the fruit for color. Still others use laser lights to look at the fruit. We have, and use many of these different styles of sorters. We have found that they all can do a fairly good job, but none have proven perfect.
You might have noticed that there are a variety of Soft-Sorters and Color-Sorters that we use; this is because all these technologies have their pluses and minuses. Each blueberry variety, in different stages of maturity, has the possibility to cause each machine to react or sort it differently. Meaning, at different times during our season, one style of Soft-Sorter or Color-Sorter might work better than another. We run multiple sorting lines at the same time and if this is happening, we can focus using that line at higher volumes. We still use the other systems, just not running quite as fast. So far, no specific manufacture of equipment has proven to always be better than the other during our season.
Inspection Conveyor Belts: As stated before, no equipment can remove everything all the time, thus the next step in our packing lines is a visual inspection of the berries. We have long conveyor belts that have inspectors standing along each side. These inspectors look for defects or debris that the earlier machinery might have missed. The inspectors opposite each other usually work in pairs, looking for the same specific thing. One pair might be looking for under-ripe fruit while the next pair looks for soft berries or stems.
Metal Detectors: Most blueberry lines added metal detectors years ago as a way to remove possible metal and to combat shotgun shot. In the past, most farms used shotguns to scare the birds away that were eating their blueberries. We stopped using this form of bird control many years ago, so we rarely find any metal in our blueberries, but we still run all our berries through metal detectors.
Packing: At this point, the blueberries are packed into the desired size of container. The majority of these containers are plastic clamshells, though bulk boxes designed for fresh blueberries are used. Clamshells get their name simply because they resemble a clam when opened or closed. Basically, they are two plastic cups, hinged together, that close to form a light-weight container for the blueberries. One cup is usually much "deeper" and holds the fruit, while the "shallow" cup forms the lid. They are also designed with venting to let the air flow through them to help keep the blueberries cool after packing.
We pack our fresh blueberries in a number of sizes of clams, based on weight. We currently pack; 4.4 oz, 6 oz, 11 oz, 12 oz, 1 lb, 18 oz, 2 lb, 2.5 lb and 2.75 lb. We also have done some specialty packing into 5 lb bulk fresh boxes.
Like many other packing facilities, we have a mixture of ways to pack blueberries into the desired clamshells. The majority of our fresh-market fruit is packed on weigh-fillers that are partially automated. The description of how these machines work would take too much room for this page, but basically they fill each clamshell with a specific amount of fruit. Some of our packing machines are more automated than another, but they all take constant work and monitoring.
Once filled, the clamshells are labeled with the desired label and then placed into boxes, or master-cases. These master-cases are designed to hold that specific size of clamshell. Each master-case receives an box code that is printed onto it by a printer just prior to being palletized. This "box code " comes from the Lot Code we assigned to this specific fruit when we checked the fruit in.
We continually do quality control testing, or QC, on the fruit as we sort and pack it. We do this testing to ensure we maintain a USDA Grade A or better fruit quality. If the fruit coming onto the line has more quality issues; more soft or damaged fruit for example, the finished fruit going into the pack will still have the same high quality, we just have to run a little slower to reach that grade.
We record this grading information, along with other information, onto our QC sheets, giving us a document that was made at the same time as the fruit is being packed. By recording this quality information during our pack, we can make sure to maintain the best grade possible.
After the box code is printed on the master-cases, they are hand stacked onto shipping pallets. We wrap the finished pallets for shipping using corner-boards and "banded" wrapping film. Corner-boards are strong paper or cardboard based "V" shaped stabilizers that are used at the four corners of the pallet to distribute the pressure of the banding material evenly against the master-cases on the pallet. Banding is taking normal stretch wrap and compressing it down into thicker 2 to 3 inch bands that are then wrapped around the pallets. This wrapping design lets the air continue to flow through the master-cases. Once wrapping is done, the pallets are then placed into the holding cooler, waiting for pick-up.
Like the clamshells, the master-cases are also designed with venting so that once they are stacked on a pallet, the vent slots lineup, allowing air flow through the pallet of berries. This helps to continue keeping the berries cool.
We keep track of each pallet of fruit with a pallet number that is place on the sides of the pallet. This pallet number lets us tell a customer exactly what is on a specific pallet, along with any information they might request on those blueberries. The box code is also recorded with each pallet number. Between QC sheets, box coding, pallet numbers, Lot Numbers and receiving tickets, we have multiple ways of verifying what fruit is in every box of frozen fruit we pack.
If you have been paying attention, you may have noticed that at no time did I say we wash the blueberries. Blueberries can normally have several weeks of what is considered to be good shelf-life once they are picked. Washing a blueberry changes that to just mere days. Water causes a blueberry to accelerate the process by which it goes from a firm-good berry to a soft-mushy berry.
The industry is still working on ways to clean blueberries for fresh-market without getting them wet. There are a couple of things that have come-out recently, such as ozone and dry misters, but nothing has as-yet to prove itself as the end-all answer.
As with other growers and packers in the fruit and vegetable industry, we have many food-safety programs in place to help protect our customers. One of the best ways to do that is to remind you to always wash your fresh fruit and vegetables before eating them.
Picking For Fresh
Fresh-market blueberries are picked and handled slightly differently than those that are picked for Frozen-market, or Processed, blueberries. Both markets are picked for the best quality and freshness, but there are slight differences that are taken into consideration when picking for them.
The first consideration is when to pick. Fresh-market blueberries are usually picked a little earlier than those destined for frozen. For fresh-market blueberries you need to make sure that the berries are not just ripe, but at the peak of their firmness. If the berries are to be for the frozen-market, they can usually wait a day or two longer.
We pick our fresh-market blueberries by hand, but mechanical harvesters are used more and more for picking blueberries. Hand labor is not only getting more expensive, but harder to come by. The technology of mechanical harvesters has come a long ways, but machines are generally a little rougher on the berries than the human hand. As the cost and lack of hand labor increases, mechanical harvesters will become more prevalent for all areas of blueberry picking.
Another aspect to be considered is the variety of the blueberry. We harvest over a dozen different varieties of blueberries, each with their own differences. Most of those differences are in when they become ripe during our season, but there are other differences, such as size, coloring and taste. Some varieties are much firmer and work much better for fresh-market than others. We have varieties that are very small, almost as small as wild blueberries and others that get as big as, well you can see an example in the picture above.
Once the decision is made to pick, time becomes the enemy. When a blueberry leaves the bush, it's like a mini count-down clock starts for that berry. This count-down varies greatly depending on a vast number of things; variety, ripeness at picking, temperature of storage, size of pack, how far they travel, etc. It all comes down to how fast we can move them through our system and keeping the "Cold-Chain".
Picture in your mind each step that a blueberry goes through as a "link" in a chain. Picking the blueberry is one link. Transportation from the field is another link. Blueberries stay firmer and last longer if they are kept cool. Most people in the industry recommend a storage temperature of 33 - 35 degrees. Controlling the temperature at each step, each link, is there-fore important, thus the phrase "Cold-Chain".
We try to insure that with-in 45 minutes after our blueberries are picked, that they are moved into some form of cooling process. At the farm, that is our receiving cooler. If the fruit is being picked at a remote field, we use reefer trailers.
The other part of the equation is speed. We try to work on a 24 hour turn-around. This means that from the time the blueberries come in, we have cooled, sorted, packed and prepared for shipment those same berries.
The Fresh-market Line
All the blueberries that come to us go through some form of procedure to prepare them for our customers. Fresh-market blueberries are no different. They just go through less than blueberries destined for frozen or dehydrated.
After the blueberries have completed check-in; variety, weight & source documented, quality checks done, Lot Code assigned and berries cooled, they are ready to be packed. We use different kinds of equipment to help us inspect, sort and pack our fruit. The following is a basic run-down of our normal packing-line equipment used for fresh-market.