Varietal distinctness in physical and engineering properties of paddy and brown rice from southern India

Paddy and brown rice samples were investigated for its physical characteristics which would aid in designing of the equipment and apparatus for processing of grains as sorting, grading and transportation with ease. Significant difference was observed among the different physical properties as geometrical (length, breadth, thickness, equivalent diameter, sphericity, volume, surface area, aspect ratio) gravimetrical (bulk density, true density, porosity etc.) and frictional characteristic such as angle of repose, hygroscopic properties as moisture and water activity and color of paddy and brown rice kernels. Among geometrical properties length was found the maximum in paddy of Mapillai samba (8.21 mm) and Palkudavazhai brown rice (6.34 mm). Among flow properties, Mapillai samba displayed the maximum value for true density of paddy and brown rice varieties respectively. Hardness was reported in the range of (344.1 ± 14.4-594.88 ± 9.5 and 209.31 ± 4.00-395.99 ± 7.05 N) for different varieties of paddy and brown rice cultivars. The color of the brown rice was read as L*, a*, b* where it varied from 36.22 ± 0.71-61.71 ± 0.81, 4.00 ± 0.18-15.29 ± 0.48 and 16.59 ± 0.52-23.81 ± 0.15 respectively. Brown rice varieties can generally be categorized as short bold, long bold and medium slender as per their length and breadth ratio. The significant differences in physical properties of the various cultivars studied, emphasis on varying processing techniques. The physical properties of selected brown rice varieties studied are widely cultivated in southern India, owing to its high nutraceutical potentials.

Cytochrome unfolding pathways from computational analysis of crystal structures

We have developed a model to study the role of geometrical factors in influencing the early stages of unfolding in three cytochromes: cyt c', cyt c-b562 and cyt c. Each stage in unfolding is quantified by the spatial extension λ̂i of n-residue segments, and by their angular extension 〈βn〉. Similarities and differences between and among the three cytochromes in the unfolding of helical and non-helical regions can be determined by analyzing the data for each signature separately. Definite conclusions can be drawn when spatial and angular changes are considered in tandem. To facilitate comparisons, we present graphical portraits of the three cytochromes at the same stage of unfolding, and in relation to their native state structures. We also display specific segments at different stages of unfolding to illustrate differences in stability of defined domains thereby allowing us to make specific predictions on the unfolding of corresponding internal and terminal helices in cyt c' and cyt c-b562. Our work accords with an earlier experimental report on the presence and persistence of a hydrophobic core in cyt c.