September 4, 2003

 

Chickpea Extends Shelf Life of Bread

Adding chickpea to bread significantly reduces moisture loss, which adds to the shelf life of bread, according to Clifford Hall III, North Dakota State University Cereal Science assistant professor. "Our initial work has shown that, by supplementing the bread with chickpea flour, we can extend the shelf life of bread by several days," Hall says.

The chickpea plant is a cool-season, deep-rooted annual legume that works well in cereal crop rotations. Chickpeas also are very nutritious, high in protein and fiber, with very little fat. It is classified into desi or kabuli types based primarily on seed color. Desi chickpea has a pigmented tan to black seed. Kabuli chickpea, sometimes called "Garbanzo bean," has a white to cream-colored seed. North Dakota is one of the leading producers of chickpea in the U.S.

Hall’s research looks to utilize low-grade chickpeas. Currently low-grade chickpea is used as animal feed or dumped. Low-grade chickpea is cracked, broken or smashed. "Low-grade chickpea has the same nutritional value so if we can utilize the nutritional benefits of the chickpea in other products such as enhancing protein quality in breads, thus adding value to the low-grade chickpea," Hall says. "When we talk protein quality, we’re talking about the basic building blocks which are amino acids. Often we have a limiting amino acid, which in wheat is lysine. If we supplement the bread with chickpea flour we then have a more complete protein due to the high lysine content in chickpea."

The chickpea flour is fermented and then added to the bread formula at a rate between 5 and 10 percent. The percentage of chickpea flour added is still being optimized, Hall notes. "Yeast is an ingredient in traditional bread. What we’re doing is replacing some or all of the yeast with fermented chickpea. Along with replacing the yeast, we get the additional benefit of extending shelf life."

Hall has used a formula going as high as 15 to 20 percent chickpea but found that the texture becomes too firm. "You actually get more of a flatbread-type product when you go to that high a percentage as compared to what is considered a loaf.

Loaf volume is often a critical quality measurement looked at by bakers. Using the 5 to 10 percent formula, volume was approximately the same as the regular bread formula using yeast. That would indicate that there is no detrimental effect at the 5 to 10 percent level for large-scale production using chickpea flour, Hall says.

Hall is working with Mehmet Tulbek, a PhD student from Turkey. His work is to identify the micro-flora involved in the fermentation process. If the active cultures can be identified then the process of chickpea fermentation can be standardized making it more competitive with yeast in the bread making process. It’s the same premise as making sourdough bread in which a starter culture is used instead of yeast, Hall says.

Consumer acceptance is another issue Hall will study. "There is a slight difference in taste," Hall says. "At what level would a consumer notice a difference is what we want to find out. There is a slight difference in taste and color at the percentage level we’ve been using. It’s more reminiscent of an artisan bread you might get at a restaurant or bakery."

Among the sponsors of Hall’s research are the Alternative Crops Program, the USDA’s Cool Seasons Food Legume Program and NDSU.

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Source: Clifford Hall III, (701) 231- 6359, clifford.hall@ndsu.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu