Pull a baked product off the shelf at a local supermarket and soy is likely to appear on the ingredient label. In the past 10 years, soy has gone from a little known food in the United States to a highly sought after product; and now stands as both a fuel and a commonly used ingredient, hailed for both its healthful and functional benefits.

Soy's popularity began to rise in 1999 when the FDA confirmed that consuming 25 grams of soy protein daily lowered LDL or “bad” cholesterol. It approved a claim that a product can be listed as having heart benefits if it contains 6.25 grams of soy protein, which is 25 percent of the recommended daily amount.

In 2000, the American Heart Association (AHA) released a statement suggesting that “it is prudent to recommend including soy protein foods in a diet low in saturated fat and cholesterol.”

A more recent study from Northwestern University's Feinberg School of Medicine, Chicago, shows the isoflavones in soy may benefit asthma patients. Other studies have shown that isoflavones may help protect against some cancers.

Soy is the only commonly-consumed food that offers isoflavones — primarily genistein and daidzein — a type of phytochemical, or plant chemical. Many phytochemicals offer health benefits in relation to cancer and heart disease, according to the SoyFoods Council. Researchers continue to examine whether isoflavones alone hold healthful benefits or if soy protein combined with isoflavones produces the positive effects, notes Mian Riaz, Ph.D., director of food protein research and development, Texas A&M University, College Station.

While studies have shown soy may protect against osteoporosis and some cancers, help control weight and ease menopausal symptoms in women, other studies have contradicted these results. In 2006, an AHA committee analyzed the results of 22 randomized studies that took place in the 1990s and early 2000s in an effort to reach one conclusion. They found soy protein only lowered LDL cholesterol by 3 percent and had little to no effect on the risk factors for heart disease. Results were mixed regarding soy's ability to slow postmenopausal bone loss. Soy's effect on the prevention of certain cancers was found inconclusive. The study, however, did confirm that using soy protein could be beneficial for health because of its high content of polyunsaturated fats, fiber, vitamins, minerals and low saturated fat.

“Initial estimates for soy had been that it lowered cholesterol by at least 10 percent, but in the last seven to eight years the studies have shown smaller decreases,” says Mark Messina, Ph.D., consultant to soy companies and adjunct associate professor with Loma Linda University, Loma Linda, Calif. “A 3 percent decrease in LDL as reported in the 2006 AHA analysis was on the low end of the estimated range as other similar analyses have shown as much as a 5 percent reduction. Although a lot less potent than drugs, shifting the mean cholesterol of the population downward by 3 percent to 5 percent is still quite important; as a result, heart disease rates will likely decrease by as much as 10 percent. Soy is definitely a heart-healthy food. It isn't going to lower your cholesterol to the target by itself, but definitely will provide benefits as part of a balanced diet.”

More recent studies continue to show that soy may contain disease fighting and postmenopausal benefits. According to a study conducted by researchers from The National Cancer Institute, women who ate about one serving of soy per day between the ages of 5 and 11 were 58 percent less likely to develop breast cancer than were women who consumed little soy when young, Messina says.

In 2007, a study published in Maturitas, The Official Journal of the European Menopause and Andropause Society, concluded soy isoflavone extract exerted favorable effects on vasomotor symptoms and was a safe, effective alternative therapy for postmenopausal women. A study published June 2007 in the Annals of Internal Medicine concluded “24 months of treatment with genistein has positive effects on bone mineral density in osteopenic postmenopausal women.”

Thus the debates and studies continue regarding the scope of soy's healthful potential.

Use and application

Soy is especially beneficial to bakers because it offers a variety of functional attributes, including the ability to bind water, replace allergens, cut costs, improve texture and shelf life, whiten bread and help achieve finished product elasticity.

Whole soybeans contain 35 percent to 36 percent protein. When oil is removed from the soybean, the protein content increases to 50 percent, notes Riaz. Soy protein concentrate is produced at 65 percent protein after some of the carbohydrates and sugars are removed. Soy protein concentrate can be further processed into soy protein isolate at 90 percent protein, he adds.

Both processing technology and flavor have come a long way since soy was first introduced to the baking industry. “Processing technology has improved so much that now manufacturers can get rid of a lot of beany flavor, especially when processing flour. The soy is further processed in an extruder and using techniques with steam and deodorization,” Riaz says. He adds that today, most companies producing soy products offer masking flavors to cover the remaining beany flavor in soy; a change from five to 10 years ago when few companies had such masking flavors available.

Givaudan Taste Essentials offers a line of flavor modifiers and masking agents to aid in the challenges associated with flavoring soy products, says Jeff Spencer, director of flavor creation, Givaudan, Cincinnati.

Not only are more masking flavors available, but some companies are using mechanical extraction methods in place of hexane extraction, which is not permitted for organic products, says Peggy Dantuma, manager, bakery applications lab, Kerry Ingredients, Hoffman Estates, Ill. Hexane is used as a solvent to strip the oil from the soy. Using hexane extraction reportedly gives the soy a bitter aftertaste. Kerry uses mechanical extraction methods and also offers non-genetically modified soy.