Background and methodology
The objective of this research was to determine whether there are physical and chemical differences in organically and conventionally grown rice that contribute to flavor and texture differences, as determined by descriptive sensory analysis, an objective tool. Five different cultivars were grown at Beaumont, Texas , with 100 or 50 percent recommended nitrogen fertilizer under conventional management, or with chicken litter under organic management.
The mean protein content of each cultivar grown with the 100 percent N rate was significantly higher than the cultivar grown organically or at the 50 percent N rate. The mean protein contents of the cultivars grown organically and at the 50 percent N rate did not significantly differ. Slickness, which correlates negatively with protein content, was significantly higher in four of the five organically grown rice cultivars than in the same cultivars grown conventionally using the 100 percent N rate. There was no significant difference between the slickness of the cultivars grown organically and conventionally using the 50 percent N rate. Roughness and hardness, which have a weak positive correlation with protein content, also differed significantly with fertilizer input in some of the cultivars. Observed differences in pasting and cooked textural properties of cultivars grown with different fertilizer types and input were the result of differences in protein content and not organic management, per se. In addition, no differences in flavor were observed due to management method. These results demonstrate that rice grown on land that is being transitioned to organic production is not expected to have significant differences in cooking or processing quality. The organic management method resulted in reduced protein content and a change in texture that may positively affect consumer acceptance of organically grown rice in markets that prefer rice that is slicker.
Champagne, E. T., Bett-Garber, K. L., Grimm, C. C., and McClung, A. M. (2007). Effects of organic fertility management on physicochemical properties and sensory quality of diverse rice cultivars. Cereal Chemistry, 84(4), 320-327. Available at: http://cerealchemistry.aaccnet.org/toc/cchem/84/4.