Project Number: 3625-21000-050-05
Project Type: Specific Cooperative Agreement

Start Date: Sep 29, 2004
End Date: Sep 28, 2009

Objective:
1)To understand the mechanism of starch granule initiation and growth through investigation of granular and molecular structures of starch in the kernels of inbred B73 at different developmental stages. 2)To develop value-added products from GEM line starch that displays desirable properties, such as for manufacturing resistance starch and for production of corn syrup and alcohol.

Approach:
Starch granules will be isolated from kernels of B73 at varying development stages (from five days after pollination [DAP] to maturity) for studies of granule initiation and development by using scanning electron microscopy (SEM) and confocal microscopy to investigate the shape and size of granules and the internal structure development of the granule, respectively. Thermal properties, amylose content, and amylopectin branch-chain length will also be studied. To develop value-added products six GEM lines, AR17056:N2025-574-1-B-B-B, CUBA164:S15-118-6-9-B-B-B, CUBA164:S15-7-9-1-B-B-B, DKB844:S1601-206-1-B-B-B, DKB844SS1601-289-1-B-B-B, and DKB844:S1601-3-2-B-B-B 03, which display high retrogradation, have been selected for production of low-cost resistant starch using a novel extrusion technique developed in the PI's research group. Resistant starch thus produced will be subjected to enzyme hydrolysis following the AOAC method. Starch from GEM lines with low gelatinization temperature (AR16026:S17-237-2-B-B-B, and AR17056:N2025 select#10-B-B-B), and low retrogradation rate (CUBA164:S2008a-481-B-B-B, and CUBA164-S15-81-7-2-B-B-B) will be analyzed for amylopectin branch chains and selected for tests of enzyme digestibility.