Prediction of rice texture from starch profiles measured using high-performance liquid chromatography

Starch determines a large proportion of the textural properties of cooked rice. The amylose: amylopectin ratio plays a significant role in the functionality of native starch. In this study a medium-grain rice cultivar, ‘Bengal’, was used for starch structure characterization using high performance size-exclusion chromatography (HPSEC). This cultivar is characterized by having lower amylose content (15% to 20%) than long grain cultivars and being sticky when cooked, similar to short-grain cultivars. Rice samples were harvested in 1999 from five locations around Arkansas at state verification trials where cultural practices are closely monitored. Samples of this cultivar stored at a specified moisture level for a pre-determined period of time were also subjected to texture analysis by means of a Texture Analyzer. The data measured with the HPSEC was related to instrumental texture attributes. Chemical characterization data (carbohydrate profiles) of rice samples were used to predict texture attributes of cooked rice such as hardness and stickiness. Instrumental texture attributes of hardness and stickiness were successfully predicted for Bengal rice from starch-profile data obtained though HPSEC analyses. Both attributes proved to be well predicted, based on their high coefficients of determination of 0.97 and 0.85, respectively. The statistical analysis indicates that starch structure characterization using HPSEC may be related to instrumental measurements of texture attributes

Apparatus and method for predicting meat tenderness

An apparatus and method for predicting meat tenderness, particularly with respect to raw meat, is disclosed. The invention does not require the removal or destruction of any cuts of meat from the carcass to which the method is applied. The method allows for the identification of tender meat product that might not be identified as tender using conventional United States Department of Agriculture quality grading methods. It includes the insertion of one or more blunt, flat-tipped blades into a meat sample, measuring a value such as stress, force, or energy upon insertion of the blade, and calculating a tenderness factor based on a tenderness threshold

Free fatty acid formation and lipid oxidation on milled rice

ABSTRACT: Milled rice was stored at 37°C and 70% humidity and sampled regularly for 50 d. Rice surface lipid was extracted with isopropanol and analyzed for free fatty acids (FFA) and conjugated diene (CD) contents. Diffuse reflectance Fourier transform infrared (DRIFTS) spectra of the rice samples were also obtained. FFA and CD levels increased together during rice storage and exhibited three distinct phases. DRIFTS identified a decrease in intensity at 1746 cm -1 (ester, -C=O) and increases in intensity at 1731 cm -1 (aldehyde, -CO) and 1714 cm -1 (fatty acid, -C=O) during storage, which correlated well with the chemical analysis data. DRIFTS spectral data were analyzed by a partial least squares regression method to identify spectral regions that correlate strongly with measured FFA and construct prediction models. Overall, the mid-infrared region (4000-400 cm -1 ) gave the best model (R = 0.98, root mean square error of cross-validation = 0.05) and also predicted the FFA content of milled rice well. The DRIFTS technique has potential for use in studying qualitative chemical changes on the milled rice surface lipids and for predicting FFA on milled rice