Technical Talk: June 2007

Soy Much to Offer

This column is written by Dr. John Michaelides of the Guelph Food Technology Centre, 519-821-1246, www.gftc.ca.

Question: What is new in soy ingredients, and how they can produce good quality, healthful baked goods? 

Answer: Soybeans are pulses containing high amounts of good quality protein and oil. Traditionally in North America, soybeans have been crushed to extract the oil, which is used for commercial applications in frying or in the production of shortenings and margarines by the process of partial hydrogenation. The hydrogenation process is responsible for the development of the trans fats in these ingredients.

The meal left over after the extraction of oil was originally used as animal feed, because of the high nutritional value of its protein. Gradually, new ingredients were developed from the meal, and made their way into various food products for people. These ingredients include soy grits and flours, as well as soy protein concentrates and isolates. Soy ingredients are used in food products for two main reasons: to provide some functionality due to their protein content, thus replacing eggs and other more costly ingredients; and, more recently, to deliver health benefits. In the past 10 to 15 years, soy has been shown to provide many health benefits to the human body and, as a result, products containing soy ingredients are becoming more of a mainstream than a niche market. Numerous scientific studies have resulted in substantial evidence, leading to the permission of a health claim in the United States for products that contain a specified amount of soy protein. This claim is not yet allowed in Canada.

Specifically, soy ingredients can be used in bakery products as replacers for more expensive ingredients, such as eggs and non-fat dry milk.  Soy flours, protein concentrates and isolates are used in breads and rolls, cakes and many other baked goods. They can improve the water absorption and handling of dough, provide body and resiliency, and tenderizing of the finished baked goods.  In addition, soy protein may extend the shelf life of the baked goods, because these proteins retain free moisture during the baking process. They may also help with the emulsification of fats with other ingredients in doughs or batters.

Enzyme-active soy flours (with high lipoxygenase activity) may be used at low levels to bleach flour to improve mixing tolerance of the dough or to impart flavour to bread.

Although their functionality has been demonstrated and understood, use of traditional soy ingredients in baked goods presented various challenges. Also, these ingredients were only partially successful in delivering the full functionality replacing other expensive ingredients. In addition, because they are a known allergen, introduction of soy ingredients in the food-manufacturing environment presented additional challenges.

These challenges, however, have been substantially overcome by major research efforts, and successes on two fronts: the breeding of new and improved soybean varieties; and the introduction of new manufacturing processes for the soy ingredients.

 New varieties of soybeans have been developed using both classic breeding techniques and genetic modification. Specifically, Vistive is a variety developed by Monsanto that is low in linolenic acid. Other new varieties with low linolenic fatty acid content include Treus, developed by Dupont, and Asoya, developed by Iowa State University. The oil from these varieties is naturally much more stable than normal soybean oils, and therefore does not require hydrogenation. This improvement means that unhealthy trans fats are not created during the processing needed to stabilize the oil.

Another new soybean variety, Prolina, has been developed using classic breeding techniques, and contains higher amounts of protein — specifically the 7S and 11S proteins. These particular proteins are very important for the functionality of ingredients produced from soybeans, and are used in many food systems. Other varieties have been developed with different sugar composition to improve digestibility, or with higher amounts of isoflavones — chemical compounds called phytoestrogens that are responsible for many of the health benefits of the soybeans.  These new varieties provide processors with raw materials to develop new, improved ingredients for applications in different food products.

In addition to new ingredients, new and improved processing technologies are also emerging, and are resulting in more functional ingredients with better performance in a variety of food products.  Soyadore, an ultra-fine soy flour, is manufactured by Prograin, a Quebec-based company, using a new, patented technology. The flour is unique, in that it has no soy aftertaste, even when used at higher amounts.  Moreover, its very small particle size allows applications in many non-traditional soy food products.  It is produced from the whole soybean, and contains all the components – providing the total health benefits, including the oil. In addition, it is produced from organic, non-GMO beans. 

New processes from Japan also provide ultra-fine soy flours with various degrees of functionality, as well as soy brans with exceptionally high isoflavone content. These brans are quite pleasant in taste, an improvement from the normally bitter flavours they usually possessed.

New developments in soybean processing in recent years have also resulted in the availability of new protein concentrates and isolates with much improved functionality that can be used successfully in many food systems. These new and improved soy ingredients can now be used in a variety of baked goods, ranging from breads and rolls, to cakes and doughnuts, with a better functionality, and at higher amounts, to assist us in developing healthier products.
 
For more information, or fee for service help with product or process development needs, please contact the GFTC at 519-821-1246, by fax at 519-836-1281, or by e-mail at gftc@gftc.ca.