March 1, 2000

Internal quality sorting is on the way

Packers hope to earn a premium for apples with guaranteed sugar and firmness levels.

BY GERALDINE WARNER

"This is not to say that there will be no more bad apples in a box, but the chances of that happening should be much decreased."

Dr. Nathan Reed

On-line sorting of apples by internal quality will be tested at the packing plant of Stemilt Growers, Inc., Wenatchee, Washington, this season.

The company will use a soluble-solids testing system from Compac Sorting Equipment Limited of New Zealand, but is also interested in a system being developed by Rich Ozanich of Berkeley Instruments, Inc., Richland, Washington.

Ozanich's system would assess both soluble solids levels and firmness of the fruit on line, but is not in commercial production yet.

Dr. Nathan Reed, Stemilt's director of research and development, said Japanese-made soluble-solids testing equipment has been used in Japan for some time, but it was expensive and slow.

"Speed is an issue, but also cost," he said. "To be competitive in our marketplace, you need to address both those issues--economics and speed."

Incorporating internal quality testing on a line is not just a technological issue, Reed pointed out. The new equipment can sort fruit fast enough to grade fruit on line for quality parameters other than color. But that means that the number of inventory items--which is already very large--could increase exponentially.

Another challenge is to figure out what level of soluble solids--and ultimately firmness--equate to a good-tasting apple, and that's likely to vary from variety to variety.

"We're still in the learning phase in terms of how different varieties might be received in the marketplace," Reed explained. "What the consumer perceives as sweet and still characteristic of apple flavor is not totally determined yet."

Stemilt will do tests this summer in which consumers will be asked to rate fruit of various soluble solids levels.

An appropriate minimum sugar level in Fuji might be 15° Brix, for example, whereas in Red Delicious it might be only 13° Brix, Reed said. "Just because it's sweet doesn't mean that everybody's going to love that. You still have to have the factors of firmness, and acidity, and other volatiles present."

Stemilt's objective is to move away from drawing general conclusions about fruit lots based on sampling, to testing each apple. This should improve consistency of fruit in the box and enable the company to eliminate the lower quality fruit and guarantee customers a minimum quality based on a number of factors. It is hoping for a premium for guaranteed top quality fruit.

"If we can put a consistent product in the box, then the result would be greater satisfaction from the consumer and a pleasing experience upon consumption," Reed said. "Then you get a repeat purchase. This is not to say that there will be no more bad apples in a box, but the chances of that happening should be much decreased."

Concerning the cost of the equipment, Reed does not envision that all fruit will be sorted for internal quality at the outset, because not all buyers will demand it. The equipment might be installed only on certain lanes of the packing line.

"It's not like you have to turn on a light and everything has to go that way," Reed said. "This is something we will gradually get used to."

Rich Ozanich said he has developed his equipment to the point where it is fast enough to operate on line and he hopes to demonstrate it to commercial packers soon. However, it is not ready for commercial production. He is patenting it and hopes by demonstrating that it can work, he will be able to attract the investment needed to commercialize it.

Like other equipment that's already available, Ozanich's system uses near infrared (NIR) to measure the soluble solids levels, but his also measures firmness. "We hope that's a key advantage we have over some other folks," he said.

Because the system penetrates deeply into the fruit, he believes it can also detect internal disorders, and could have potential for sorting other fruits, such as oranges.

In terms of firmness testing, the system hasn't correlated as well as he would have liked with the standard Magness-Taylor penetrometer, a problem also encountered with other efforts to develop firmness testers. However, it's hard to know how accurately the Magness-Taylor test itself reflects the true firmness of an apple. It measures the pressure of a specific spot on the apple, but the actual firmness can vary around the apple, Ozanich pointed out. His system takes several readings all around the fruit.

He's been doing taste tests and questions how important firmness really is in Red Delicious. "Some of the firmest Red Delicious apples are not very good tasting apples," he commented.

The industry seems to believe that firmness is the driving quality parameter, but he's not sure it really is. "While people don't want a mushy apple, they really want it to be flavorful, juicy, and sweet with a balance of acids. All those parameters can be measured with NIR."

So far, Ozanich's system can eliminate fruit of 8 pounds pressure and under with almost 100 percent accuracy, but when the cutoff is nearer 12 pounds, it eliminates some good fruit and keeps some bad. Even though it's not the best correlation, Ozanich believes it's useful and practical.

He is looking for a partner with engineering and manufacturing resources to help him build his equipment on a commercial scale. "We're looking to try to team with some major players in the industry or even pursue investors if we can," he said.

Berkeley Instruments expects to receive funding from the Spokane Intercollegiate Research and Technology Institute to help commercialize the system and develop the business.

Acceptance

Ozanich believes his invention is timely for the fruit industry.

"There's some interest," he said. "I think there will be a lot of people realizing that quality is going to be the name of the game. It will have to be an industry leader who installs one of these units. It may well be Compac's, though I would rather see it be a U.S. company. I think when someone like Stemilt installs one of these units and shows you can improve returns to the grower, that's all it will take and there will be a wave of acceptance."

Mike Hambelton, director of marketing at Stemilt, believes the industry will adopt internal quality sorting because there will be a price spread between fruit of guaranteed firmness and sugar levels and fruit of unknown internal quality. And he believes it's a matter of some urgency.

"I feel that the sooner we have it running, the better off we will be," he said. Although it could result in greater diversions of fruit to processing, Hambelton said growers will learn how to grow the type of fruit they get paid for.

Per capita consumption has been stagnant for a long time, he pointed out. "If we're going to improve per capita consumption, we're going to have to give the consumer a better product. Other commodities are giving the consumer either a new product or a product that's more consistent--a product that they want to spend their money on, more so than apples--and until we do that, we're going to be right where we are on the per capita consumption."

Defects

Tommy Hanses at Washington Fruit and Produce Company in Yakima, Washington, said his company doesn't have plans yet to test internal quality on line.

"The next step for us would be a color sorter that sorts out defects as well," he said. "I think that would be really helpful. We have 28 to 30 sorters on line and all they are doing is trying to sort out surface defects."

Some packing equipment manufacturers are working on that aspect. Technology developed at the University of Arkansas has been licensed to Agri-Tech, Inc., Woodstock, Virginia, a major manufacturer of fruit and vegetable processing equipment. The system uses infrared and near-infrared imaging to distinguish the stem end and calyx of fruit from true defects, a difficulty that foiled earlier attempts at defect sorting. Inventor Yang Tao says his system is 99.6 to 99.8 percent accurate and can scan 50 fruit per second.

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