J. Gross, B.P. Marks and M. Daniels. Cereal Chem. 75, 714-720 (1998).A trained texture profiling panel and an extrusion cell fitted into the TA.XT2 Texture Analyzer were used to quantify textural characteristics of three cooked rice cultivars exhibiting small differences in tlexture. Nine sensory and five instrumental parameters were used to establish predictive models for the sensory characteristics evaluated. Most effectively pred3icted were hardness (R2=@.62) and toothpack (R2=0.70). Partial least square regression techniques gave the following RAP (relative ability of prediction) values: hardness 0.52, cohesiveness of mass 0.60, toothpull 0.73, and toothpack 0.54. These values take into account the accuracy of the sensory methodology and provide a more accurate evaluation of the quality of the predictive models. Poor predictability was related to small textural differences between test samples, and need for better statistical methods applicable to such situations.A. S. Sz.

In both domestic and international markets, the end‐use quality of rice affects its market value and acceptability to consumers. The effect of various postharvest processing treatments on sensory characteristics of cooked rice was investigated using sensory descriptive methods. Cooked rice quality was affected (P < 0.05) by rough rice wet holding, drying temperature, storage temperature, and storage duration. Cohesiveness of mass and hardness of sample were significantly affected by the temperature of drying. A higher storage temperature reduced the cohesiveness of mass and gluiness, while sample hardness, clumpiness, and geometry of slurry increased. Storage duration had more profound effects on the sensory attributes studied. Perceived starchy note, clumpiness, gluiness, and overall sensory impression decreased after four weeks of storage. Storage duration also influenced hardness, moisture absorption, sulfury notes, and cardboardy notes.

Cereal Chem. 77(2):259-263The effects of postharvest conditions (i.e., rough rice moisture content, storage temperature, and storage duration) on sensory quality of one longgrain rice cultivar grown in Arkansas (Cypress) were evaluated using a professional descriptive sensory panel. Eight textural (adhesion to lips, hardness, cohesiveness of mass, roughness of mass, toothpull, particle size, toothpack, and loose particles) and six flavor attributes (overall rice impression, sulfur, starch, grainy, metallic, and cardboard) were identified as most important in describing the sensory characteristics of cooked Cyress rice. Postharvest conditions had significant effects on rice sensory quality, and regression models illustrated the effects of each postharvest variable and their interactions. 2 Corresponding

Rough rice (cv. Cypress) from the 1995 season was harvested, dried, and stored in laboratory-scale studies. Treatments included pre-drying conditions, drying conditions, storage temperatures, and storage durations. Temporary wet storage prior to drying affected cooking properties (p<0.005) and peak viscosity (p<0.005). Drying treatments affected head rice yield (p<0.05), cooking properties (p<0.001), and peak viscosity (p<0.05). Storage temperature was related (p<0.05) to cooking properties and peak viscosity via a second-order relationship. Head rice yield and cooking properties were also affected (p<0.05) by storage duration.

The effects of rough rice pre-drying, drying, and storage treatments on the gelatinization and retrogradation properties of long-grain rice (cv. Cypress) were studied via differential scanning calorimetry (DSC). The experimental variables included two pre-drying conditions (immediate and delayed drying), two drying conditions (high and low air temperatures), and four storage treatments (no storage, and storage at 4, 21, and 38°C for 20 wk). Gelatinization of the rice flour in water occurred at temperatures from 73 to 86°C, with an enthalpy of 8.3 to 9.7 J/g. Storage temperature had a significant effect on the gelatinization characteristics. Rice stored at 38°C exhibited higher (p < 0.0005) gelatinization enthalpy and peak temperature than did rice stored at 4 and 21°C. Pre-drying treatments had no significant effect on the gelatinization enthalpy and peak temperature, but did on the onset temperature (p < 0.05). The pre-drying and/or drying treatments had significant (p < 0.05) effects on the retrogradation onset and conclusion temperatures of gelatinized rice. Storage of rough rice significantly (p < 0.0001) increased retrogradation enthalpy, but did not affect the peak temperature of the retrogradation endotherm.