Physicochemical properties and leaching behavior of eight U.S. long-grain rice cultivars as related to rice texture

There are many long-grain rice cultivars produced commercially in the U.S.; however, little work has been done on correlating the structure and physicochemical properties of starch with their texture. The physicochemical properties, leaching behavior, and texture attributes of eight longgrain rice cultivars were studied. Differences were observed in the approximate composition of kernels, including crude protein (6.6-9.3%), crude lipid (0.18-0.51%), and apparent amylose content (25.5-30.9%). These cultivars also differed slightly in thermal properties, such as onset temperature (73.7° to 77.4°C) and peak temperature (78.8° to 81.9°C). Although they showed a similar pasting temperature, their peak viscosities ranged from 680 to 982 Brabender units. The amount and the molecular size distribution of the leached starch molecules varied greatly among the samples. The leached amylose, instead of the apparent amylose, was suggested to play an important role in cooked rice texture

Characterization of starch structures and properties of maize mutants from the Oh43 inbred line

Starches were isolated from a dent maize (Zea mays L.) inbred line Oh43, from single endosperm mutants and from the double-mutant combinations within Oh43. The thermal properties of the starches, including onset temperature (T[subscript] o), peak temperature, gelatinization temperature range, and enthalpy ([delta]H) of gelatinization and retrogradation and percentage of retrogradation, were determined by differential scanning calorimetry. A Voland-Stevens texture analyzer was used to measure gel strength. Double mutants generally had higher T[subscript] o and [delta]H for gelatinization and lower T[subscript] o for retrogradation, and lower gel strength measurements than those of single mutants. Sixteen mutant genotypes along with the normal genotype were selected for characterization of their fine structures and physicochemical properties. Each genotype exhibited different elution patterns of its native and isoamylase-debranched starches by gel permeation chromatography (GPC), and showed distinctive morphology revealed by scanning electron microscopy. The amylose-extender (ae), dull-1 (du1), and sugary-1 (su1) genes were associated with increased amounts of amylose and intermediate materials, whereas the waxy (wx) gene produced starch with essentially 100% amylopectin. The discrepancy in amylose percentage by using GPC and iodine affinity in some genotypes may have resulted from the presence of a large amount of intermediate materials in those starches. The mutants containing the ae gene had low amounts of branching in the amylopectin; mutants containing the du1 and/or su1 genes had a high amount of branching. Among all the structural characteristics, amylose content was the most important factor affecting the physicochemical properties. Other structural characteristics were weakly correlated with physicochemical properties. Five mutant genotypes (ae, brittle-1 (bt1), du1, ae bt1, and ae du1) were further fractionated, and the amylopectin and intermediate materials were obtained for study of their structural characteristics and physicochemical properties. The amylopectin and intermediate materials from the same starch source exhibited different structural characteristics and properties, as did their fractions from different starches. This study demonstrated that genetic background plays an important role in determining the fine structure of starch components. The effects were evident of interactions between recessive mutant genes on the structures and properties of starch

Coating composition and process for baked products to impart the attributes of fried products

Provide a composition and the process for baked food products that impart the sensorial attributes of fried food products. The composition is in the form of a batter coating, either powdered or wet, which is applied to a food product, and when baked, has the taste, texture and appearance of a fried food product. The batter coating includes at least an enzyme-modified starch or flour or other starch-containing material having oil absorbing capabilities. The enzyme-modified starch is plated with a liquid cooking oil in order to bring the liquid cooking oil into the process, and the batter coating retains the incorporated liquid cooking oil during processing to impart a fat fried texture, appearance and taste to the baked food product

Characterization of jasmine rice cultivars grown in the United States

Jasmine rice from Thailand accounts for about 60% to 70% of U.S. imported rice, primarily due to its preference by ethnic Asians as well as the general American population. Recently new U.S. jasmine rice cultivars have been developed independently at three rice research stations in Arkansas, California, and Louisiana, but their properties have not been characterized. The objective of this research was to characterize and compare the physical appearance, chemical composition, thermal and pasting properties, cooked rice texture, and starch structures of the newly developed U.S. jasmine rice from Arkansas, California, and Louisiana, to be compared with jasmine rice samples from Thailand. In general, the U.S. varieties had smaller length/width ratios, darker color, and greater ash and lipid contents than the Thai controls. The Arkansas samples were similar to each other as well as one Louisiana sample, CLJ01 2017, and the other Louisiana samples were similar to each other; but rice of both origins was different from Thai jasmine. Calaroma-201 was found to be the most similar to the Thai jasmine rice out of the U.S. varieties from Ward’s hierarchical cluster analysis of all attributes. These findings can help the U.S. rice industry to develop U.S. jasmine rice cultivars closer to Thai jasmine rice

Properties of gluten-free pasta prepared from rice and different starches

Rice is one of the few cereal products that does not contain gluten. However, the absence of gluten poses problems in the structure of and cooking quality of rice pasta. The objective of this project was to investigate the addition of starch on the physicochemical properties and cooking quality of rice-based pasta. Rice-based pasta was prepared from parboiled long-grain rice flour with the addition of 25% cooked starch from different sources. The color and pasting properties of the ground pasta flour were measured by a chroma meter and a Rapid Visco Analyser, respectively. The pasta was cooked to the optimum cooking time to evaluate its hardness, stickiness, adhesiveness and resilience by using texture profile analysis with a texture analyzer. The water absorption and cooking loss of pasta were determined by weight difference. Overall the addition of starch improved the processibility of rice pasta and enabled the b* value (yellow color) of the uncooked rice pasta to be close to that of the semolina control. The pasting properties of rice pasta containing common corn starch were close to those of the semolina control. Upon cooking, the rice flour control had higher water absorption and greater cooking loss than the semolina control. The addition of starch decreased both the water absorption and the cooking loss relative to the rice flour control. The effect of starch addition on the textural properties of rice-based pasta varied with the type of starch. The addition of waxy starch or tapioca starch resulted in rice pasta with an increase in hardness and stickiness, whereas the addition of common corn, Hylon V, or Hylon VII resulted in rice pasta with a decrease in hardness, stickiness, and adhesiveness. This project demonstrates that the addition of starch significantly changes the color, pasting, cooking and texture properties of rice pasta, and these changes are governed by the type of starch incorporated into the rice pasta. Gluten-free rice pasta can be prepared with properties similar to the semolina pasta by incorporating starches

Application of cross-linked rice starches as drug delivery matrices in monolithic tablets

The sustained release properties of regular and waxy rice starches and their derivatives were studied in tablets. The starches were cross-linked to different levels with epichlorohydrin, and the sustained release properties, swelling power, and rheological characteristics of the matrices prepared were determined. Propranolol hydrochloride was used as a model drug. The sustained release properties of waxy rice starch improved with increasing cross-linking levels, whereas cross-linking had little impact on the functionality of regular rice starch matrices. There was an increase in swelling power for both regular and waxy rice starches as cross-linking levels increased. Both starches showed an increase in the storage modulus when cross-linking was increased, with the regular rice starch matrices showing greater differences among samples. Regular rice starch matrices showed an independence of frequency as cross-linking increased, indicating a “true gel” characteristic, whereas waxy rice matrices behaved as a “weak gel.” Both regular and waxy rice starches displayed a decrease in creep and recovery profiles with an increase in cross-linking level. Waxy rice starch showed potential as a sustained release agent in tablets

Characterization of Short-grain Rice Cultivars Grown in Japan, California and Arkansas

Arkansas and California are the two leading rice-producing states in the U.S. Arkansas predominantly long- and medium-grain rice and California primarily medium- and short-grain rice. Although short-grain rice accounts for less than 2 % of U.S. rice production, the demand for short-grain rice is rising because of increasing popularity of sushi and sake. Because of its premium price and different applications, short-grain rice may open up new opportunities for rice farmers in Arkansas. The objective of this study was to characterize the physical, physicochemical and texture properties of rice cultivars grown in Arkansas versus in Japan and California. Three short-grain rice cultivars from the 2016 crop year were collected, including RU9601099 from Arkansas, CH-202 from California, and Koshihikari from Japan. The rice cultivars were characterized for kernel appearance, chemical composition, amylopectin chain-length distribution, and gelatinization, pasting and textural properties. RU9601099 was found to have a smaller width and a greater length/width ratio and whiteness than the other cultivars. RU9601099 was high in protein and ash contents, but low in amylose content. RU9601099 and CH-202 shared a similar average chain-length of amylopectin. RU9601099 had significantly greater gelatinization temperatures and enthalpy and peak and trough viscosities. When cooked, RU9601099 exhibited greater stickiness, whereas Koshihikari exhibited greater hardness. The results reveal significant differences in some properties among the three short-grain rice cultivars, although both RU9601099 and CH-202 are crosses of Koshihikari, and demonstrate the importance of environmental factors affecting rice properties

Composition and process for baked food products to impart the sensorial attributes of fried food products

A composition and process for cooked food products is provided to impart the sensorial attributes of fried food products. The composition is in the form of a batter coating, either powdered or wet, which is applied to a food product, and when cooked, has the taste, texture and appearance of a fried food product. The batter coating includes at least an enzyme-modified starch or flour or other starch-containing material having oil absorbing capabilities. The enzyme-modified starch is plated with a liquid cooking oil in order to bring the liquid cooking oil into the process, and the batter coating retains the incorporated liquid cooking oil during processing to impart a fat fried texture, appearance and taste to the cooked food product

Passive scalars, random flux, and chiral phase fluids

We study the two-dimensional localization problem for (i) a classical diffusing particle advected by a quenched random mean-zero vorticity field, and (ii) a quantum particle in a quenched random mean-zero magnetic field. Through a combination of numerical and analytic techniques we argue that both systems have extended eigenstates at a special point in the spectrum, $E_c$, where a sublattice decomposition obtains. In a neighborhood of this point, the Lyapunov exponents of the transfer-matrices acquire ratios characteristic of conformal invariance allowing an indirect determination of $1/r$ for the typical spatial decay of eigenstates.Comment: use revtex, two-column, 4 pages, 5 postscript figures, submitted to PR