Cereal Chem. 76(5):764-771Although amylose content is considered the most important determinant of cooked rice texture, this constituent falls short as a predictor, because cultivars with similar amylose contents may differ in textural properties. Thus, amylography is used as one of a battery of tests, in addition to measuring amylose content, to improve differentiation of cultivars. The purpose of our study was to determine how well amylography conducted with a Rapid Visco Analyser (RVA) serves as a predictor of cooked rice texture, alone and in combination, with amylose content. Textural properties of 87 samples representing short-, medium-, and long-grain rice cultivars were assessed by descriptive sensory and instrumental texture profile (TPA) analyses and related to RVA measurements.None of the cooked rice textural attributes, whether measured by descriptive analysis or TPA, were modeled by RVA with high accuracy (i.e., high r 2 ). Sensory texture attributes cohesiveness of mass, stickiness, and initial starchy coating and TPA attribute adhesiveness had the strongest correlations with RVA measurements. Setback explained most of the variance attributed to models describing these attributes; the strongest correlation was with cohesiveness of mass (r = 0.69; equivalent to coefficient of determination, r 2 = 0.47). Inclusion of amylose and protein contents in regression analyses did not strengthen models. Exclusion of samples that cook atypically, based on amylose content or gelatinization temperature types, slightly improved the accuracy of RVA measurements for predicting cooked rice texture.

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The effects of drying conditions, final moisture content, and degree of milling on the texture of cooked rice varieties, as measured by texture profile analysis, were investigated. Instrumentally measured textural properties were not significantly (α = 0.05) affected by drying conditions, with the exception of cohesiveness. Cohesiveness was lower in rice dried at lower temperatures (18°C or ambient) than in that dried at the higher commercial temperatures. Final moisture content and degree of milling significantly (α = 0.05) affected textural property values for adhesiveness, cohesiveness, hardness, and springiness; their effects were interdependent. The effects of deep milling were more pronounced in the rice dried to 15% moisture than that dried to 12%. In general, textural property values for hardness were higher and those for cohesiveness, adhesiveness, and springiness were lower in regular‐milled rice dried to 15% moisture than in that dried to 12%. In contrast, hardness values were lower and cohesiveness, adhesiveness, and springiness values were higher in deep‐milled rice dried to 15% moisture than in that dried to 12% moisture. Deep milling resulted in rice with lower hardness values and higher cohesiveness, adhesiveness, and springiness values.

Cereal Chem. 74(5):566-570The extent that postharvest processing parameters influence the sensory quality of cooked rice is not well known. In this investigation, the effects of drying conditions, final moisture content, and degree of milling on the flavor of rice varieties Bengal, M-401, and Koshihikari were determined by descriptive sensory analysis. No trends were observed indicating an increase or decrease in flavor attributes with increased drying temperatures (18-60°C). Intensities of desirable and undesirable flavor attributes were higher in rice dried to 15% moisture compared to 12% moisture. The effects of deep-milling on flavor attribute intensities were dependent on moisture content and variety or location.The sensory quality of cooked rice strongly affects the economic value of the grain in domestic and world markets. This quality varies due to factors such as variety, growing location, cultivation methods, harvesting methods, and processing after harvesting (drying, storage, milling). These factors affect constituent content and their interactions in the rice that govern sensory quality. Conventionally, sensory quality of rice has been assessed by a combination of sensory and physicochemical property evaluations. Through statistical methods, relationships between sensory and physicochemical properties are determined, allowing assessment of sensory quality. Sensory evaluations are generally preference ratings of flavor and texture, with the emphasis on textural attributes. A preference panel states their opinion of how much they like or prefer a rice sample based on personal examination and judgment according to individual senses. The panel is intended to represent a target population. If samples are presented to panelists representing a different population, results will differ.An alternative to preference sensory analysis for evaluating sensory properties of rice is descriptive sensory analysis (Meilgaard et al 1987). In contrast to preference evaluations, descriptive analysis is an objective methodology. Descriptive analysis utilizes trained panelists that have been screened for normal abilities to perceive sensory attributes. They are not a sample of the population, but an analytical instrument. They evaluate the intensities of the various sensory attributes using a universal intensity scale. Following calibration, panelists theoretically should give the same results for a given sample, regardless of nationality, age, or gender.USDA Agricultural Research Service scientists in collaboration with industry, U.S. rice breeders, and international scientists have initiated investigations to develop universal methods for assessing and predicting the sensory quality of rice for domestic and international markets. As part of this collaborative effort, the effects of drying conditions, final moisture content, and degree of milling (DOM) on the flavor and texture of U.S. medium grain varieties have been determined using descriptive analyses and instrumental means. This article reports the influences of these...

Our objective was to determine flavor quality changes, and measure changes in key volatile compounds, sugars and acidity, in fresh-cur Gala apples packaged in film to control the atmosphere during distribution. Gala apples were washed, cored, sliced, dipped in a browning inhibitor and packaged in a barrier film. Afrer 0, 5, 9, 12 and 14 days at l C , the apple slices were evaluated for descriptive flavor attributes, gas chromatographic volatiles, sugars, pH and titratable acidity. Flavor attributes, sweet aromatic jlavor and sweet taste had a maximum intensity between 5 and 9 days. Sugars remained constant. Results suggest that perceived flavor intensity increased the first few days afrer preparation and packaging, then dissipated. Compounds that decreased during storage were farnescene, hexyl hexanoate, 2-methyl-butyl hexanoate; hexyl 2-methyl butanoate and heryl butanoate decreased until 10 days, then started to increase. Hexyl acetate and hexane increased during storage.