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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #112780
Title: CHARACTERIZATION OF UNIQUE STARCHES FROM DEVELOPMENTAL LINES

Author
item YULIN, JI - IOWA STATE UNIVERSITY
item SEETHARAMAN, KOUSHIK - IOWA STATE UNIVERSITY
item Duvick, Susan
item Pollak, Linda
item WHITE, PAMELA - IOWA STATE UNIVERSITY

Submitted to: Corn Utilization Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Starches from developmental corn lines were screened for unique starch properties. These lines are being developed as a part of the Germplasm Enhancement of Maize Program (GEM), which is a collaborative effort among the public and private sectors to develop breeding materials using useful exotic germplasm. The thermal properties were determined using Differential Scanning Calorimetry (DSCC) on 20 individual kernels per ear of corn. Based on these screenings several lines with unique starch thermal properties were identified with potential applications in the food and non-food industries. Starches from two lines with the most unique properties, PI-480182 and PI-480183, were used for further studies. The objective of this study was to further characterize these starches to establish the structure-function relationships that would explain the unique thermal behavior of these starches. Of the physical attributes, only starch granule size distribution showed significant differences compared to normal starch. The unique starches had a higher average granule size and a greater proportion of larger granules than normal starch. The qualitative degree of crystallinity based on X-ray crystallography showed no differences. Further studies to quantify the amount of crystallinity in these starches using techniques, such as solid phase NMR, will be explored to explain the differences in thermal properties. No significant differences were observed in the levels of amylose an amylopectin or their molecular weight distributions, thus far. Characterization of the branch chain lengths of the amylopectin moiety might reveal differences in the unique starches.