Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Master of Science (MS)

Department / School

Health and Nutritional Sciences

Abstract

Since cereals and cereal-based products are relatively cheap sources of energy and protein, they are highly consumed in all countries. Wheat is the major cereal, consumed in different food products, especially bread. Bread is one of the oldest foods known throughout history. It has played an important role in the development of mankind and is still one of the principal sources of nutrition. Today, bread contributes healthy dietary components to the modern lifestyle. Flour is used in most breads, but various problems can be associated with flour, such as allergies and loss of nutrient components due to milling and refining. To overcome this, fortification is one solution, which not only will add nutrients to the bread, but it also can help reduce risk of certain diseases and health conditions such as cancer, cardiovascular diseases, and malnutrition. Thus, using various sources of flours to fortify products made with wheat flour, especially bread, is important. In the first component of this study, five different flours (20% of each flour plus 80% of wheat flour) were used as alternatives to wheat flour in production of the traditional Iranian bread Barbari. These flours were amaranth, barley, distillers dried grains with solubles (DOGS), rye and oat. Proximate analyses were conducted in order to quantify the moisture, fat, fiber, protein and ash content of each product. Also tests were done to understand the change in the color, thickness and texture of final products. Results showed that the gluten content of each flour had significant effect on the texture and thickness of the bread. As for the color, it was shown that the bread made with rye flour was the darkest (L *= 62.18) and the one made with oat was more red (a*=9.49). As for the chemical properties of the breads, it was determined that bread made with 20% DOGS and 80% wheat flour had the highest value of fiber (3.57%) and protein (12.55%). The bread made with rye had the highest value fat ( 1.09%) content. Overall, it was determined that adding different flours as alternatives to wheat flour can change the physical and chemical attributes of final product significantly. In the second part of this thesis, DOGS was used in conjunction with SSL (sodium stearoyl lactate) in order to fortify Barbari bread. In this experiment, three levels of DOGS substitution (0%, 10% and 20%) and three levels of SSL substitution (0%, 2% and 5%) were used, and the physical and chemical properties of the dough and bread were determined and evaluated. The results for baked breads showed that incorporation of20% of DDGS and 0% SSL caused a significant increase in the amount of fiber (4.09%) and protein (13.79%). As for the physical attributes, using higher amounts of DOGS caused a darker color (L *= 71.03). Different mixolab and rapid visco analyzer (RVA) parameters also were measured and determined in order to study the rheological changes and behaviors in the dough, so as to understand the best level of substitution of both DOGS and SSL. In the third part of this thesis, the focus was on another type of bread which is widely consumed in western countries. Latin American tortilla is the most popular bread which was traditionally consumed in Mexico. However, today the consumption of this bread is not limited to Mexico but it is highly consumed in the United States as well. In this study, three levels of DOGS (0%, 10% and 20%) were substituted with wheat flour and the physical and chemical properties of the final products were evaluated. As the results showed, addition of DOGS flour can lead to a better and softer texture of the tortillas. In the 20% DOGS level, minimum force was required to rupture the tortilla. The color of the tortillas substituted with I 0% and 20% of DOGS were darker (L *= 64.11 and 59. 9, respectively) in comparison to the control. As for the chemical composition of the tortillas, the samples fortified with 10 and 20% of DOGS had a higher protein (9.73% and I 0. 78%, respectively) value compare to the control. As the level of DOGS increased, the fiber content of the tortilla increased (2.33%) as well. Overall it was determined that addition of DOGS as an ingredient in the preparation of wheat tortillas and Baribari can increase the nutritional value of the final product as well as improve the textural properties of the these two breads.

Library of Congress Subject Headings

Bread -- Composition

Distilling industries -- By-products

Bread -- Iran

Tortillas -- Latin America

Enriched foods

Format

application/pdf

Number of Pages

153

Publisher

South Dakota State University

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