Title: Effect of nitrogen application on the physicochemical properties of selected rice varieties Authors
Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: August 22, 2013
Publication Date: N/A
Technical Abstract: Rice with high amylose concentration (AM), low breakdown and high setback, as measured by the Rapid Visco Analyzer (RVA), is best suited for use by the parboiling and canning industries as these properties correlates with reduced starch solids loss and improved grain integrity after processing. This study was conducted to determine if varieties that have high AM differ for parameters associated with processing quality and if these properties are affected by the amount of fertilizer nitrogen (N) applied during field production. Nine rice varieties that have high AM along with one (reference) variety with intermediate AM were studied in replicated field trials conducted in Texas and Arkansas, using three rates of N application (standard, low, and high). Varieties were significantly different for all traits measured and, except for protein, there were no significant variety x N interactions. N rates significantly impacted AM and protein concentrations and all RVA parameters, but not starch gelatinization temperature (GT) parameters. Although the variety Cheniere had one of the highest AM, it had the lowest peak, trough, and final paste viscosities as measured by RVA and this type of paste viscosity profile is undesirable for parboiling. The varieties Jaya, Rondo, and Shu 121 were not different in AM from Cheniere or Dixiebelle, the highest ranking varieties. However these three varieties had significantly higher peak, trough, and final RVA paste viscosities and significantly lower onset, peak, and final GT than Cheniere and Dixiebelle. Among the varieties with high AM and intermediate GT, Bowman had significantly lower RVA setback 1 than Sabine and significantly lower onset and peak GT as compared with Zhe 733. This indicates that starch structure of high AM varieties may differ and impact processing quality.