Document Type

Thesis - University Access Only

Award Date

2012

Degree Name

Master of Science (MS)

Department / School

Health and Nutritional Sciences

First Advisor

Padmanaban Krishnan

Abstract

The purpose of the study was to combine high protein and high fiber fractions (from the soy and corn processing industries) with wheat flour in order to study their rheological characteristics and food efficacy. Pizza crust formulation was explored as a food matrix. Soy protein concentrate (SPC) was combined with Corn Distillers' Dried Grains (DOG) in various ratios (70:30, 50:50, and 70:30) and these blends were in tum used to replace white wheat flour at 5, I 0, and 15% substitution levels. Physico-chemical analysis, amino acid profile, and functional properties, dough rheology (Farinograph, Mixolab, and Texture analyzer) were determined. Cooked pizza crust was evaluated for nutritional, sensory, and baking properties. A balance of soy (SPC), corn (DOG) and wheat flour (white wheat patent flour) was studied for their optimal contribution to nutrition and food functionality. Among the three SPC:FDDG combinations studied, blend I with SPC and FDDG in the 70:30 ratio showed statistically significant acceptability from the point of view of functionality (increased amino acid, fiber and protein content), rheology, and sensory characteristics. A Triangle Test could not distinguish between the control and I 0% Soy DOG pizza. The panelist could not also distinguish differences between 10% and 15% fortified pizzas. A seven point hedonic scale showed the best overall score for pizza fortified at the 15% supplementation level. A comparison of nutrient composition of freeze dried pizza showed improvements in protein and fiber content of 10% and 15% fortified pizzas over the control pizza. Protein, fiber, and moisture content increased to 22. 7%, 1.2%, and 26.1 % (blend- 1 (70SPC:30FDDG) from 19.1 %, 0.65%, and 18.6%, respectively, in the 15% supplementation. This represents a gain of 3.6% protein and 7.5% fiber over the control pizza expressed on a dry weight basis. Increased water content is an important parameter for yield and shelf life. Previous studies on DOG fortification showed 20% as the maximum limit beyond which sensory quality became unacceptable. In our study, fortification as high as 15% with that of specific SPC: DDG (11.5: 4.5) shows promise for improvement of protein, fiber and moisture composition.

Library of Congress Subject Headings

Flour -- Analysis
Soy proteins
Distillers feeds
Rheology

Publisher

South Dakota State University

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Rights Statement

In Copyright