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Document Type

Dissertation - University Access Only

Award Date

2013

Degree Name

Doctor of Philosophy (PhD)

Department / School

Health and Nutritional Sciences

First Advisor

Padmanaban Krishnan

Abstract

Rheological tests are a cost effective way of monitoring how different raw materials, ingredients, and growing conditions affect the performance of wheat flour during processing. Wheat end-use quality has become the main driver of the wheat market. Hard white wheat (HWW) is the newest class of U.S. wheat. It has been developed for the dual purpose of making breads and noodles. There is a need to identify reliable quality tests that correlate well and consistently with end product quality. Multiple instrumental techniques were investigated to determine wheat end-use quality. Strain hardening is an important dough property. Higher strain hardening index values (n) have been associated with higher loaf volumes. Our first study identified 3 extensibility parameters that contributed to n; dough strength (Rmax), dough extensional delay (EDiff), and dough elasticity (Ei). N was correlated to the loaf volume more often than any other parameter and was positively correlated to loaf volume across different environments suggesting that n may be a good criterion to screen flours for their baking performance. The Rapid Visco-Analyzer (RVA) is usually used to screen among noodle flours. It evaluates the pasting characteristics but provides no information regarding protein quality. The Mixolab determines both the dough mixing and pasting characteristics. Therefore, it might be a valuable tool to evaluate the noodle making potential of HWW. Many Mixolab parameters were correlated to noodle quality. The Mixolab dip was correlated to most textural attributes. Prediction models for hardness, cohesiveness, resilience, chewiness, noodle brightness with similar R-squares were developed based on both the RVA and Mixolab parameters. Resistant wheat starch (RS4) was used to increase the fiber content of wonton wraps. Eggs are usually used to improve the wonton extensibility. Vital gluten (VG) and wheat protein isolate (WPI) were used as potential substitutes. Overall, the fortification with RS4 had minimum effects on dough and wonton quality. However, adding 5% RS4 decreased the wonton extensibility by 15%. WPI affected the rheological properties of dough but yielded wontons similar to the wonton wraps made with eggs. Combining 5% RS4 with 2% WPI yielded the product with the best characteristics.

Library of Congress Subject Headings

Wheat -- Quality -- Testing.
Rheology.

Description

Includes bibliographical references.

Format

application/pdf

Number of Pages

277

Publisher

South Dakota State University

Rights

In Copyright - Educational Use Permitted
http://rightsstatements.org/vocab/InC-EDU/1.0/

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