Karen L. Bett

Correlation Between Cooked Rice Texture and Rapid Visco Analyser Measurements

ABSTRACT Although 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 r2). Sensory texture attributes cohesiveness of mass, stickiness, and initial starchy coatin...

Effects of Postharvest Processing on Texture Profile Analysis of Cooked Rice

ABSTRACT 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 an...

Effects of Drying Conditions, Final Moisture Content, and Degree of Milling on Rice Flavor

ABSTRACT The 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.

Meat flavor: contribution of proteins and peptides to the flavor of beef.

While the majority of meat flavor is lipid in origin, the contribution of peptides and amino acids to overall meat flavor should not be overlooked. Amino acids and peptide levels have been shown to change with postmortem aging in muscle and with dry-curing, a process similar to PMA. Variation in protein, peptide, and amino acid composition have also been shown to occur with heating and with post-heating storage of meat. This makes a large pool of reactive components that may directly affect flavor or indirectly affect flavor by reacting with reducing sugars to form Maillard reaction products and Strecker degradation products that impact meat flavor. Further research in this area should continue with particular emphasis on natural peptide flavor enhancers, modulators, and potentiators.

Instrumental assessment of cooked rice texture characteristics: a method for breeders.

ABSTRACT Sensory textural characteristics of cooked rice (61 samples) were predicted using a miniature extrusion cell and the novel data analysis method Spectral Stress Strain Analysis (SSSA). Thirteen sensory texture characteristics evaluated using a trained descriptive panel and stress values from an extrusion test were used in combination with partial least squares regression to evaluate predictive models for each of the sensory attributes studied. Among the textural attributes evaluated by the panel, four (stickiness, hardness, cohesiveness of mass, and uniformity of bite [relative ability of prediction values (RAP) > 0.6, n = 61]) could be satisfactorily predicted using an instrumental test and subsequent SSSA. The quality of the models determined varied for the two grain types evaluated. This instrumental method provides a valuable screening tool for rice breeders.

Sensory and statistical analyses in meat flavour research

In 1985, the Southern Regional Research Centre (SRRC) established a new research unit to establish sensory and objective definitions of food flavours in meat, catfish, eggs and peanut products. Included in this research was a focus on the chemical and biological origins of flavour compounds as well as causes of flavour deterioration and undesirable flavour development. Of course, the ultimate goal was to serve both the consumer and the food industry through quality assessment.

Use of Electronic Nose Technology to Examine Apple Quality

Apples, traditionally an ethnic food, have become a globally desired food commodity. According to Smock and Neubert (1950), “the original home of the apple (Malus sylvestris is not know but it is thought to be indigenous to the region south of the Caucasus, from the Persian province of Ghilan on the Caspian Sea to Trezbizond on the Black Sea.)” Apples have probably existed from prehistoric times in both the wild and cultivated states in Europe from the Caspian Sea to the Atlantic Ocean (Hulme and Rhodes, 1971). Apples were available as early as 100. B.C., but “Pearmian” appears to be the first variety recorded in history appearing in 1204 in a deed relating to the lordship of Runton in Norfolk. In America, there are records as early as 1647 of apples having been grafted on seedling rootstocks in Virginia. By 1773, three years before the American War for Independence, apples from America were found in the London markets. The spread of the cultivation of apples in the United States is ascribed to Johnny Appleseed (John Chapman) who established nurseries in Pennsylvania and Ohio.