Making edible, nutritious wrappers from oregano         

[AUG. 17, 2005]  URBANA -- Although oregano may be best known for its use as a spice, it also has antioxidant properties that can help prevent cardiovascular disease and antimicrobial properties that can help prevent food from spoiling. Researchers at the University of Illinois set out to develop a film made with oregano and soy protein that could be used to cover sausage, candy or other products. The film would be clear, edible, provide preservative help to the product and have the added health benefits of being antioxidant as well as containing soy nutrients.

Graduate student Edel Pruneda-Olguin said that, unlike the edible casings commonly found on sausages in the U.S., the wrapping on sausages in Mexico, where he is from, must be taken off first.

In the lab, Pruneda-Olguin mixed soy protein isolates in the form of powder and an edible plasticizer (i.e., glycerol and sorbitol), then added dried Mexican oregano. The essential oil of the oregano was already extracted and discarded so that the remaining powder could be mixed with water easily.

The potential hurdle for this project is the color change of the film when the oregano extract is added. A clear film was developed only when oregano extract was not added. It was the control sample of the project. "The more oregano extract is added, the more antimicrobial and antioxidant benefits," said Pruneda-Olguin. "But the films also turn darker brown in color, making them less desirable as a food wrapper."

One of the next phases of the project will be to test the edible wrapper to see if it has retained the antioxidant properties in the oregano throughout the processing.

Pruneda-Olguin is one of 38 students who have come to the U of I to study through a USAID-TIES grant. He has been working on developing applications of oregano extract to the soy protein films in Soo-Yeun Lee's laboratory in the Department of Food Science and Human Nutrition in the College of Agricultural, Consumer and Environmental Sciences.

Elizabeth Jeffery and Elvira de Mejia facilitate the grant program and are charged to enhance and sustain institutional linkages between Mexico and U of I. "The aim of the program is to enhance teaching, research, cultural education to meet Mexico's needs," said de Mejia, "to build a wider bridge and strengthen the mutual understanding between the U.S. and Mexico."

The program has already resulted in more than 20 joint publications in international peer-reviewed scientific journals and has given the professors at U of I a better understanding of the agricultural and food problems in Mexico.

CONACYT, the Mexican equivalent of the U.S. National Science Foundation, signed an agreement in early 2005 to fund 50 Ph.D. students to come to the U of I to study over the next five years and to provide the funds for joint research projects. The grant will provide $2 million over five years to pay tuition and living expenses for three years of graduate study in value-added plant foods for Mexico's brightest young scientists.

[Debra Levey Larson, University of Illinois]

Past related article in LDN

• Grant funding Mexican students' graduate work yielding health and economic benefits