A team consisting of Oklahoma State University professors in the departments of horticulture and landscape architecture, nutritional sciences, and biosystems and agricultural engineering have found a way to reduce the fat in pecans and create healthy by-products as well.
 
 

In the Beginning

Sue Knight, retired OSU nutritional sciences associate professor, said she and Marilyn Waters, a graduate research assistant, started the project as a study to produce lower fat content and extend shelf life in pecans. They began by lowering the fat content using FDA approved food oil solvents.

"We were able to get some of the fat out, up to 30 percent, if the kernels were chopped, but only about 5 percent with whole pecan halves," Knight said.

Knight said pecans are between 60 and 70 percent fat, with a large percentage monounsaturated.

"Granted, it is a very healthy type of fat, and we need more monounsaturated fat in our diet. But manufacturers are worried about the fat level when stating it on the product nutritional label," Knight said. "We wanted to help market pecans for a calorie concerned public."

"Although our product was well rated, there were lots of things about the equipment and procedures we were unhappy with. We were way beyond our capabilities, engineering wise. We needed help."

Knight said the pecan product was well rated, but the researchers were unhappy with the available equipment and procedures.
 

Teamwork

That is when a group of interdepartmental professors came together as a team. Niels Maness, professor of horticulture and landscape architecture, along with Gerald Brusewitz, professor of biosystems and agricultural engineering, stepped in to get the ball rolling. They began studying the use of a gas-under-pressure type of extraction to obtain the lower fat pecan.

Brusewitz said this new way of oil extraction is a method developed by OSU to be used on food products. It is a high pressure process using supercritical carbon dioxide at levels of 4,200 pounds per square inch.

How much oil can be removed from pecans?

"About 30 to 40 percent of the pecan oil can be extracted by flowing the supercritical carbon dioxide through the pecans for a three hour duration," Maness said.

The team project began as a study to find a way to extend the shelf life of intact pecan halves. Pecans were chosen for the project because they go rancid quickly, only having a shelf life of three to four months at room temperature.

"We are still using good samples from our 1996 extraction, so we are not quite sure of the shelf life of the lower fat pecan," Maness said. "So far, the shelf life has proven to be over two years in duration."

Oil By-Products

The lower fat pecan is not the only product resulting from the oil extraction process.

"Pecan oil is a high grade oil that can be used in a salad dressing," said Knight. "It also can be a good substitute for olive oil when cooking."

Knight said research is currently being done to develop a cake mix that has pecan oil already included. Once the low fat cake is developed she will then try to produce it as a dry mix for easier manufacturing.

Pecan oil is not only used as a food product. It has been proven to work as a nonfood product as well.

"You wouldn't think pecan oil would make a very good profit, but you can make much more money using it as a wood stain than as a food source," Brusewitz said.
 
 

Oklahoma Benefits

Now that the oil extraction process has been proven using liquefied gas and supercritical carbon dioxide, manufacturers are beginning to look at production.

"There is a company looking at putting a manufacturing plant in Oklahoma that will be able to extract oil not only from pecans, but from other food products as well," Brusewitz said.

"The type of food oil extraction process used in this project has given manufacturers an incentive to come to Oklahoma," Maness said.

Oklahoma's will not only see a new company coming into the state, but they may also see the result of a similar process discovered long ago.

"The actual process of using liquefied gas to extract oil was patented in Oklahoma by a local crude oil company," Maness said.

Maness said although the process was patented long ago, no one considered using a process done on crude oil as a process to extract oil from foods for human consumption.
 
 

Promoting Oil Extraction

The team is working on ways to help promote on-going oil extraction research, by meeting with legislators, preparing pamphlets and producing a short documentary about the process and results.

Maness said promotion is an on-going team process. He said a team approach is what has made the oil extraction project a success. One example of teamwork is the staff in the Department of Agriculture's marketing office, who helped market the lower fat pecan to the public.

Maness said the team hopes the continuation of research support will help increase the capability of marketing and producing the lower fat pecan for retail sale by companies, such as the one coming to Oklahoma.
 
 

The Low Fat Choice

Oklahoma's will soon have the choice of products containing lower fat ingredients due to the oil extraction process. This proves team effort can get the job done.

So, when the holidays roll around and you find yourself in the store looking for those pecan pie ingredients, remember to look for the lower fat pecan ó any other pecan may not prove all it's cracked up to be.

By Faren Revard

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