Yong-Cheng Shi, Professor

Department of Grain Science and Industry, Kansas State University

Lecture for Students and Teachers

Title: PROPERTIES, MODIFICATIONS, AND APPLICATIONS OF WAXY WHEAT FLOUR AND STARCH

Time: Sep. 9, 2015, 10:00 am.
Place: the No.3 lecture hall on the third floor of the conference center

Introduction to Prof. Yong-Cheng Shi:

Dr. Yong-Cheng Shi is a professor in the Department of Grain Science and Industry, Kansas State University (KSU), Manhattan, Kansas. He received his PhD in Grain Science with an emphasis in starch chemistry from KSU in 1993. He worked at National Starch and Chemical Company from 1994 to 2005 prior to becoming a cereal grain carbohydrate faculty at KSU in 2006. He has 15 granted US patents and numerous corresponding patents throughout the world. He is an associate editor for Cereal Chemistry and a member of Advisory Board for Starch and Food Digestion journals. His research areas include: Starch structure and functionality, physcial, chemical and genetic modifications of starch, enzymatic modifications of biopolymers, cereal starch digestibility and carbohydrate nutrition.

Abstract:

To realize the full potential of waxy wheat flour and starch in food applications, we have investigated (1) dry-milling of waxy wheat, (2) dough properties of waxy wheat flour, (3) pasting properties of waxy wheat flour as well as factors governing the pasting properties, (4) improving functional properties of waxy wheat flour, (5) wet milling of hard waxy wheat flour into gluten and waxy wheat starch, (6) gelatinization and pasting properties of waxy wheat starch, (7) chemical modification of waxy wheat starch, and (8) applications of waxy wheat in bread and extruded products. Doughs prepared from six waxy hard wheat flours were found to be weaker than those of from normal wheats. Waxy wheat flour had higher water absorption and lower mixing time than normal wheat flour. Starches isolated from the waxy wheat flours had similar pasting properties, yet their corresponding flours had very different pasting properties.A combination of endogenous α-amylase activity and protein matrix contributed to a large variation of pasting properties of waxy wheat flours. Changes in the morphology of waxy and normal wheat starch granules were determined by using a hot-stage microscope, and those changes were related to their pasting properties. Chemical cross-linking is traditionally used to improve pasting properties of a waxy starch. Pasting properties of cross-linked waxy wheat starches were compared with that of cross-linked waxy maize starches, which are currently used in food products. Thermal processes have been developed to improve the functional properties of waxy wheat flour and produce non-cohesive texture when the flour is cooked.

(School of Food and Biological Engineering)