Structure and Function of Starch and Resistant Starch from Corn with Different Doses of Mutant Amylose-Extender and Floury-1 Alleles

Thumbnail Image
Date
2009-03-11
Authors
Yao, Ni
Paez, Alix
White, Pamela
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
White, Pamela
University Professor Emeritus
Research Projects
Organizational Units
Organizational Unit
Journal Issue
Is Version Of
Versions
Series
Department
Food Science and Human Nutrition
Abstract

Four corn types with different doses of mutant amylose-extender (ae) and floury-1 (fl1) alleles, in the endosperm, including no. 1, aeaeae; no. 2, fl1fl1fl1; no. 3, aeaefl1; and no. 4,fl1fl1ae, were developed for use in making Hispanic food products with high resistant starch (RS) content. The RS percentages in the native starch (NS) of 1−4 were 55.2, 1.1, 5.7, and 1.1%, respectively. All NS were evaluated for pasting properties with a rapid viscoanalyzer (RVA) and for thermal properties with a differential scanning calorimeter (DSC). NS 1 had a low peak viscosity (PV) caused by incomplete gelatinization, whereas NS 3 had the greatest PV and breakdown of all four starch types. On the DSC, NS 2 had the lowest onset temperature and greatest enthalpy. NS 1 and 3 had similar onset and peak temperatures, both higher than those of NS 2 and 4. The gel strength of NS heated with a RVA was evaluated by using a texture analyzer immediately after RVA heating (fresh, RVA-F) and after the gel had been stored at 4 °C for 10 days (retrograded, RVA-R). NS 1 gel was watery and had the lowest strength (30 g) among starch gel types. NS 3 gel, although exhibiting syneresis, had greater gel strength than NS 2 and 4. The structures of the NS, the RS isolated from the NS (RS-NS), the RS isolated from RVA-F (RS-RVA-F), and the RS isolated from RVA-R (RS-RVA-R) were evaluated by using size exclusion chromatography. NS 1 had a greater percentage of amylose (AM) (58.3%) than the other NS (20.4−26.8%). The RS from all NS types (RS-NS) had a lower percentage of amylopectin (AP) and a greater percentage of low molecular weight (MW) AM than was present in the original NS materials. The RS-RVA-R from all starches had no AP or high MW AM. The percentages of longer chain lengths (DP 35−60) of NS were greater in 1 and 3 than in 2 and 4, and the percentages of smaller chain lengths (DP 10−20) were greater in 2 and 4 than in 1 and 3. In general, NS 3 seemed to have inherited some pasting, thermal, and structural characteristics from both NS 1 and 2, but was distinctly different from 4.

Comments

Posted with permission from Journal of Agricultural and Food Chemistry 57 (2009): 2040–2048, doi:10.1021/jf8033682.

Description
Keywords
Citation
DOI
Copyright
Thu Jan 01 00:00:00 UTC 2009
Collections