Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2004
Publication Date: 9/19/2004
Citation: Li, L., Blanco, M.H., Jane, J. 2004. Physicochemical properties of maize starch during endosperm development. American Association of Cereal Chemists Meetings, San Diego, CA. September 12-16, 2004. Abstract 138.
Technical Abstract: Starches were isolated from maize (B73) on 0, 5, 6, 8, 10, 12, 14, 20 and 30 days after pollination (DAP). Starch content in the kernel was 7.8% on dry basis on 0DAP, around 10% from 5 to 12 DAP, and increased rapidly from 14 (22.8%) to 30DAP (83.0%). The results suggested that the rate of maize starch biosynthesis increased rapidly after 12 DAP. Scanning electron micrograph showed that granular sizes increased with kernel development from 2-4 micron (0ADP) to 10-15 micron (30DAP). The onset gelatinization temperature of starch isolated on 0DAP (56.3 degree C) was about 5 degree lower than that of 5 to 12DAP (61.3-62.4 degree C). Starches harvested on 14, 20 and 30DAP had higher onset gelatinization temperature (67.1, 69.3, and 68.8 degree C, respectively). The retrogradation rate of starches increased from 31.6% (0DAP) to 50.1% (30DAP). The branch chain-length distributions of amylopectin analyzed by HPAEC showed the very short A chains (DP6-12) decreased with the development of endosperm, whereas the chains of DP 13-24 increased. The results indicated that branch chain length of amylopectin changed with the maturation of maize, which led to the increase of onset gelatinzation temperature of starches.