Quick Evaluation Technique Finds New Applications in Food and Agriculture

A quick evaluation technique that’s been routinely used to screen and synthesize pharmaceutical compounds may get a new application in agricultural and food technology, according to Agricultural Research Service chemist Jerry W. King. King works at the agency’s National Center for Agricultural Utilization Research in Peoria, Ill.

The technique, called combinatorial chemistry, employs the rapid use of small-scale instrumentation that has potential for evaluating environmentally-friendly processing methods. The advantage is to speed up laboratory scale evaluations, thereby reducing the cost and time associated with using larger scale processing equipment.

King has used these quick assessment techniques coupled with highly pressurized fluids, called supercritical fluids, to optimize extraction processes, to evaluate the efficiency of enzymes, and to enrich nutraceuticals and other compounds from plant-derived oils.

Nutraceuticals--compounds for which scientists have documented specific health benefits--can be obtained using supercritical fluid extraction (SFE), which has long been used to decaffeinate coffee. The final products are minimally modified because of less harsh extraction conditions.

Another Peoria scientist has used the technique to extract more and better quality cedarwood oil from juniper trees. Cedarwood oil--used in cosmetics and home odorants--is usually extracted from sawdust and wood chips by steam distillation, a method that produces low oil yields and off-odors. Using the new technique, ARS chemist Fred Eller, also in Peoria, has obtained 30 percent more oil than the yield from the conventional steam distillation process without destroying the oil's aromatic components.

According to King, the application to agricultural research can speed up laboratory research by several days and can aid scientists in determining optimum conditions before beginning large-scale processing.

King reported these findings at the 221st annual meeting of the American Chemical Society Meeting earlier this month in San Diego, Calif., where he participated in an all-day symposium, the first of its kind to focus on combinatorial chemistry and its potential uses for agriculture and food.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.

Scientific contact: Jerry W. King, ARS National Center for Agricultural Utilization Research, Peoria, Ill., phone (309) 681-6203, fax (309) 681-6686, kingjw@mail.ncaur.usda.gov.