November 28, 2002

NDSU Food Scientist Examining the Secrets of Soybeans

A North Dakota State University food scientist is studying the fundamental properties of soybeans to learn how they relate to the crop’s uses and nutritional value.

"In recent years, we have seen a trend in America where the soybean is being appreciated as a health food," according to Sam Chang. "This is a significant change in the consumers’ attitudes. Not only are they becoming aware of the value of traditional soy foods such as tofu, but in the sense of soy protein as a valuable additive to other foods."

"We are looking for the fundamental traits in soybeans that are responsible for nutritional content, taste and health benefits," Chang says. "This enables the selection and development of soybean varieties that are most value-added."

"To examine the food and nutritional qualities of soybeans, we are breaking them down to their molecular level," Chang says. "We are then able to examine bioactive components such as proteins, isoflavones (plant estrogens with possible heart-disease and cancer prevention qualities), phytate and trypsin inhibitors and the vitamins present and other basic characteristics."

Chang is also concerned with the flavor characteristics of soybean products such as tofu, soy milk and meat substitute soy protein. "We take different varieties of soybeans, or even soybeans that have been stored under different conditions, and then we process them into food products," Chang says. "We then have a panel of volunteers and lab technicians taste the products and evaluate them for their flavor, texture and other characteristics. This process gives us valuable information about what varieties are better suited to food products and how storage conditions can affect these characteristics."

Storage conditions are very important to soybeans. "Storage can greatly affect the taste of soybeans for food products such as tofu and soy milk," Chang says. "Improper storage can even lead to mold growth, which can constitute a food safety problem. We hope that this study will lead to storage regimes, especially concerning humidity and temperature, to avoid the sale of these soybeans at a discount." Funding for the storage research was provided by the National Research Initiative of the USDA and the North Dakota Soybean Council.

Adding value to soybeans is crucial to producers, especially given the growing market for edible soybeans. The price per bushel of food soybeans is considerably higher than that for oilseed soybeans. "The demand for food soybeans has risen dramatically; from a couple hundred million dollars in value in the early 1990's to around $3 billion today. Food soybean demand is increasing at a 10-20 percent per year pace. It has been predicted that by 2010 the production of soy food products will be in the range of $100 billion."

The potential health characteristics of soybeans also are great. "Soy protein has been proved to lower cholesterol," Chang says. "Other chemical compounds in soybeans such as isoflavones, saponins and phytic acid also contribute to better health. Phytoesterols (phytoestrogens) help to safely reduce symptoms in post-menopausal women, and increase bone mass and density."

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Source: Sam Chang, (701)231-7485, kow.chang@ndsu.nodak.edu
Editor: Tom Jirik, (701)231-9629, tjirik@ndsuext.nodak.edu
Writer: Scott Lowell, (701)231-7865, slowell@ndsuext.nodak.edu