There are some places in the world where people routinely drink asparagus juice … and they like it. We Americans might soon like it too, if a team of WSU researchers has its way. Joseph Powers, associate professor in the Department of Food Science and Human Nutrition, is looking for new ways to utilize leftover bits and pieces of the nutrient-rich vegetable.
“Why is this important?” asked Powers. “When you harvest asparagus with a machine, there tends to be more damage than with hand cutting, resulting in a greater number of wholesome but cosmetically damaged spears. It can’t go into the fresh market and there are no canneries left in Washington. So what do you do with it?”
Recent studies have shown that asparagus tops the list of 34 popular vegetables in antioxidant activity. The delicate green spears are packed full of the phytochemicals glutathione, rutin and folic acid.
The Washington Asparagus Commission reports that glutathione is called the “master antioxidant” in that it helps regulate other antioxidants such as vitamin A or E and is also key in removing free radicals, detoxifying carcinogens and supporting immune functions. According to Powers, about 90 percent of the antioxidant activity in asparagus comes from rutin, a bioflavonoid, which has been shown to help increase the strength and permeability of capillaries while increasing the oxygen-carrying capacity of the blood.
Hoping to discover ways to market asparagus that preserve its high nutrient value, Powers is collaborating with Juming Tang, professor in the Department of Biological Systems Engineering, and postdoctoral student Caleb Nindo. Together they are investigating both drying and juicing techniques.
Funded by the Washington Technology Center in 2005, the researchers teamed up with MCD Technologies, Inc., in Tacoma to use a unique conduction and radiation process known as the “Refractance Window™.” This method uses a thin film belt that allows heat to pass through and gently dry the vegetable. The result is preservation of a higher level of antioxidants than with other methods.
“WSU is the first place to adapt this technology to this purpose,” Powers said. “Dried asparagus powder is already marketed as a health food. And dried diced asparagus could be added to soup mixes.
“It looks good — bright green — and it rehydrates quickly,” he said. The team also is looking at using enzyme systems to help extract asparagus juice; team members envision it being used in vegetable-type juices like V-8.
