Article

Thermal and physicochemical properties of rice grain, flour and starch.

National Food Research Institute, Kannondai 2-1-2, Tsukuba, 305-8642 Japan.
Journal of Agricultural and Food Chemistry (Impact Factor: 3.11). 08/2000; 48(7):2639-47. DOI: 10.1021/jf990374f
Source: PubMed

ABSTRACT Three types of rices, namely, Thailand rice (Indica), Nipponbare (Japonica), and Himenomochi (Japonica waxy), in grain, flour, and starch forms have been studied for their thermal and physicochemical properties. In grain form, Indica was slender and Japonica rices were bold and thick. Indica had the highest protein and amylose equivalent. Protein contents in isolated starches varied from 0.2 to 0.9%. Cooked Indica grain was hardest and waxy rice was softest; stickiness was highest in Japonica rice. Glass transition temperature (T(g)) was highest in Indica rice flour (approximately 222 degrees C) and almost the same in Japonica rice flours. Melting point was highest for Japonica (approximately 264 degrees C) and almost the same for Japonica waxy and Indica rice flours. T(g) values of starches were almost the same in Indica and Japonica waxy (approximately 237 degrees C); defatting caused reduction in this property in all of the starches. Highest melting point was shown by Indica starch (approximately 276 degrees C) and was almost the same for the other two starches. Protein and fats play a critical role in glass transition and melting points of rice flours and their respective starches. Viscosities of the cooked pastes of flour and starch during cooking in an RVA instrument and their gel and other properties have been discussed.

0 Bookmarks
 · 
243 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A simple method has been proposed to synthesize environmental friendly biodegradable starch films containing gold (Au) and cadmium sulfide (CdS) nanoparticles (NPs) with significantly improved mechanical properties than pure starch films for various industrial applications. Au NPs were synthesized in vitro by using starch as a weak reducing agent simultaneously for the starch film formation. All reactions were monitored with UV–visible measurements, and it was observed that the growth of Au NPs was proportional to the amount of starch. Due to the inherent surface plasmon resonance (SPR), all Au NP starch films were UV active. Likewise, CdS NPs were synthesized in the glycerol medium and further incorporated in the starch films to make fluorescent active films. X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), and differential scanning calorimetry (DSC) measurements were used to characterize NPs as well as starch films. A systematic measurement of mechanical properties showed a high degree of tensile strength and flexibility for CdS fluorescent starch films in comparison to Au NP starch films that made the former an ideal candidate for various industrial applications.
    ACS Sustainable Chemistry & Engineering. 12/2012; 1(1):127–136.
  • [Show abstract] [Hide abstract]
    ABSTRACT: One hundred and five indica rice samples were analyzed by determining head rice yield, chalkiness, protein content, gel consistency and amylose content. Taste scores of rice were obtained by sensory evaluation. Support vector machine (SVM) and K-nearest neighbors (KNN) models were established with physicochemical properties as attributes. In each linear correlation, amylose content had highest coefficient with taste score, but in the mutual influence, gel consistency showed highest correlation. In SVM model, the accuracy of the training set and testing set were 99.0% and 93.3%, respectively; in KNN model, they were 74.3% and 73.3%, respectively. These results showed that the nonlinear relationship between eating property and physicochemical properties of indica rice was found. It was concluded that SVM, which extracts nonlinear features, can be used to effectively predict the taste class of unknown.Practical ApplicationsSupport vector machine (SVM) is an effective prediction model used to represent the eating property of indica rice. The model showed that the nonlinear relationship between eating property and physicochemical properties of indica rice. The results of the present study can also serve as a valuable resource to further explore the utilization of the prediction model in sensory evaluation of rice, and expound the relationship between eating property and other properties of rice.
    Journal of Food Quality 08/2014; · 0.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The effects of protein removal on the physicochemical properties of waxy maize flours were investigated. Protein removal caused significant reduction in the P and S contents of starches. Starch granules had a smoother surface and low protein content (
    Starch - Starke 11/2012; 64(11). · 1.22 Impact Factor

Preview

Download
9 Downloads
Available from