SENSORY TEXTURE PROFILE, GRAIN PHYSICOCHEMICAL CHARACTERISTICS AND INSTRUMENTAL MEASUREMENTS OF COOKED RICE

Three samples of raw-milled rice, and 4 differently parboiled rices we re used to study and to relate sensory perception to instrumental meas urements. Variance analysis showed that some physico-chemical characte ristics indicated great differences among rice samples: thickness of c ooked grain, length/width ratio, water uptake, elastic recovery, white core rare and amylose and protein contents. The most discerning senso ry attributes were: elasticity, stickiness, pastiness, mealiness, leng th of grain, firmness, crunchiness, time in mouth, brittle texture and juiciness. The correlation circle of the principal component analysis (PCA) showed high correlation between some sensory characteristics an d instrumental measurements. Melting texture, surface moistness, juici ness, were positively correlated with water uptake (r = 0.70, 0.61, 0. 71). Granular texture, crunchiness, brittleness and mealiness were sig nificantly affected by white core presence (r = 0.81, 0.74, 0.86, 0.83 ). Elasticity was dependent upon elastic recovery and firmness measure d by the Viscoelastograph, but not linearly. Length of cooked grain wa s correlated with the length/width radio of raw grain (r = 0.83). Past iness, compactness, stickiness were slightly influenced by the thickne ss of raw grain (r = 0.81, 0.67, 0.72). To a weaker extent, the sensor y firmness was associated with the firmness measured by extrusion forc e using an Ottawa cell (r = 0.58). PCA showed great differences in tex ture between rices. Two of the parboiled rices were very elastic, anot her was firm, granular, crunchy and mealy. The remaining two, cooked l onger, were moister and more melting. Among the 3 samples of raw-mille d rices, differences in grain length feeling and melting-granular-brit tle characteristics were distinguished.