Quality evaluation of U.S. medium-grain rice using a Japanese taste analyzer
1996
Champagne, E.T. | Richard, O.A. | Bett, K.L. | Grimm, C.C. | Vinyard, B.T. | Webb, B.D. | McClung, A.M. | Barton, F.E. II. | Lyon, B.G. | Moldenhauer, K.
Taste analyzers, developed in Japan, convert various physicochemical parameters of rice into "taste" scores based on correlations between near-infrared reflectance (NIR) measurements of key constituents (e.g., amylose, protein, moisture, fat acidity) and preference sensory scores. These taste analyzers are being used by Japanese millers and wholesalers to grade rice, both domestic and imported. This study examines the applicability of using the Satake Neuro Fuzzy Rice Taster for evaluating U.S. medium-grain rice cultivars. The Rice Taster, as presently calibrated, does not appear to be a valid tool for assessing rice cultivars with low (<18%) amylose contents. The low-amylose cultivars fell outside the range of the calibration set used by Satake. The effects of degree-of-milling and U.S. shipping practices on Rice Taster scores (S) were also determined. Conditioning of the bran during four weeks refrigerated storage led to the bran being more readily removed from the kernel during milling. This resulted in the milled rice having significantly lower protein (P < 0.0001), free fatty acids (P < 0.01), and n-hexanal (P < 0.0001) levels, increased whiteness (P < 0.0001) and milling degree (P < 0.0001) measures, and higher S (P < 0.0001) values. Deep milling significantly increased (P < 0.0001) chemical measures of amylose and significantly decreased protein and free fatty acids contents (P < 0.0001). Rice Taster measurements of "amylose" (A) and protein (B) significantly decreased (P < 0.0001) with deep milling. Moisture (C), "fat acidity" (D(a)), and milling yield (D(b)) were not significantly (P > 0.05) affected. S significantly (P < 0.0001) increased (mean 5 points) with deep milling.
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