Sorting technology

This gentle bin filler softly sets fruit in the bin as it rises and lowers to meet the fruit.

Paul Koch knew what he wanted a presizing line to do—lower inventory costs, reduce labor costs, reduce costs associated with repacking, and maintain fruit quality during storage. He also wanted the presize line to use new defect, firmness, and internal quality sorting technologies. The problem was that nobody else was using a dry system like he wanted to.
Olympic Fruit Company LLC, a medium-sized apple packer near Yakima, Washington, for years packed without presizing—resulting in “push” marketing, said Koch, Olympic’s General Manager. The company wanted to move away from the “we packed it, now we have to sell it” mentality and pack fruit to order instead.

“We wanted to provide the customer with a better product,” he said, adding that it no longer made sense to ship the oldest product to their customers. “We wanted to create sales with repeat buys and be able to send fruit out within two weeks of packing.”

During a recent precision agriculture conference in Kennewick, Washington, Koch described how Olympic Fruit put together a dry presizing line, and said they had several driving reasons for presizing. They wanted to eliminate the labor and packaging costs and fruit loss associated with repacking, a cost that hits the grower the hardest.

“We also wanted to eliminate desperation pricing and battles and complaints from the customer that happen when fruit gets old,” Koch said.

He believes that good inventory management requires keeping inventory in its lowest-cost form.

“We’re a varietal house, with Gala as our major crop,” Koch said. Because Olympic Fruit supplies Galas to a fresh-sliced processor, consistent quality is important. Moreover, he didn’t want to exacerbate the lenticel breakdown problems during storage after presizing that Galas are known for. Studies have shown that packinghouse practices like presizing with water, using soaps and cleaners, and using warm water can worsen lenticel breakdown.

He also wanted to eliminate wasted space in the bin that occurs with wet presize bin fillers as they can only fill the bins three-quarters full before water is drained out. And, he was concerned with the costs and disposal of water used in a wet presizing line and bruising that can occur during the bin filling.

First of its kind

Olympic Fruit’s dry presizer, which became operational about two years ago, is the first of its kind, said Koch. “Nobody else is doing it.”

He worked with the Dutch manufacturer Greefato put the dry line together. Greefa had a prototype of a gentle bin filler, although it was designed for cull apples and wasn’t gentle enough for fresh-market fruit. Several modifications were made to make the gentle bin filler work under Olympic Fruit’s specifications.

Water is used initially in the presizer, with fruit dumped from bins into water. But after moving through a water flume of about 30 feet, the apples move through the line without water in cup holders. They are sorted first for debris, then receive a fungicide mist treatment under a hood, are dried under fans, and are then sorted by four different technologies.

After the sorting, apples move to one of 33 bin fillers, which fill by moving the bin up and down to meet the apples that are set gently into the bin with a series of rubber flaps.

The fungicide mist eliminates potential for drench water to inoculate clean fruit with mold or mildew spores. A custom-built bin washer cleans and sanitizes each bin, with 58 jets washing the insides and outsides of bins as the bins move toward the bin filling stations. “That way, we’re putting clean fruit into a clean bin,” he said.

A robotic forklift stacks filled bins four-high and separates them according to size and quality for delivery into cold storage and controlled atmosphere rooms.

While most presizing rooms employ 30 to 40 people, Koch said, Olympic Fruit uses nine people to operate the line.

Sorting technology

Fruit is sorted by four Greefa technologies, and in split seconds, a computer considers all four components before assigning fruit a particular grade. Firmness is measured with a nondestructive device that taps fruit up to 29 times. Next, an optical grader sorts fruit by color and size. A third sort is done by weighing each piece of fruit. The last sort is a state-of-the-art internal fruit analyzer that uses infrared technology to measure Brix or sweetness, watercore, and internal breakdown. Firmness parameters specify minimum and maximum levels and allow them to pack, store, and market fruit accordingly.

The presizing technology is constantly monitored to ensure that it stays on target, said Edward Gonzales, director of presize operations at Olympic. For example, fruit is cut by hand to check the internal fruit analyzer. “We run continuous tests, checking the different sorters every fifteen minutes.”

During the 2006 season—a year with hail damage—they were able to sort by the size of the hail and create a marketable hail grade. The defect sorter also allows them to identify Granny Smith apples with sunburn early on, before fruit develops scald during storage.

Custom work

Obviously, such sorting technology is expensive, said Gonzales, and not something that all packers can afford. Olympic Fruit now runs the presizing line on a custom basis, using it for their own growers’ fruit as well as presizing fruit for other packers and growers. He noted that the customer determines the quality parameters for the sorting and picks up the fruit after it has been sorted.

“Some of the toughest customers in the fruit handling business are our competitors, and we’ve passed their scrutiny,” Gonzales said. “We invite and encourage them to come and watch their fruit being run.”

Lessons learned

“It was scary when we first started up because no one has ever done presizing under the dry concept,” Koch said. Though they were concerned about lenticel breakdown from presized fruit, they haven’t found any breakdown problems during storage.

He has learned that, “You don’t want to eliminate all culls. You could, but you don’t want to, as you would be hurting the grower by having fruit that’s too clean and too perfect. You want to leave the allowable federal percentage of defects in the pack.”

They have also learned that pack-to-order is not as easy as it sounds and puts great pressure on the sales desk. Presizing logistics during harvest is another area that requires added attention. It’s difficult to keep up with presizing when fruit harvest is at its peak.

“The good news is that we’ve packed about 15 percent more than at this time last year, with on-hand inventory down 33 percent,” he said, adding that inventory six weeks old is down 66 percent. “We want to get to the point where all the fruit has been packed within a two-week period and have greater efficiency.”