Concentration and distribution of toxic elements in rice and husk

Five varieties of rice have been analyzed to study the prevailing concentration and distribution of 10 trace elements in rice and rice husk. NAA in combination with AAS has been utilized for the determination of Hg, Pb, Cd, As, Br, Sb, Se, Ni, Al and Cs. The elemental ratios of rice to husk and within rice have been calculated to get information regarding their uptake channels. The daily supply of the elements to the human body has been estimated and from these the safety of the diet has been assessed by comparing with the suggested tolerance levels. A global distribution pattern of some of these elements in rice has also been evaluated.     

水稻线粒体DNA的热变性及热力学研究

自从1963－1964年发现线粒体DNA（mtDN）以来，人们对线粒体DNA的结构、功能等方面进行了很多研究．高等植物线粒体DNA的研究也有不少报导．线粒体DNA之所以引起人们广泛兴趣决非偶然．线粒体具有独立复制的能力，它有自己独特的DNA、rRNA、tRNA、核糖体．它是细胞的动力站，生物氧化链上某些重要的酶的一部分亚基是由线粒体基因组编码的．对线粒体DNA的深入研究，肯定会对线粒体起源问题提供有价值的线索．此外，植物的雄性不育、真核细胞的抗药性等，也都可能与线粒体DNA有关．尽管如此，线粒体及线粒体DNA的某些功能至今仍…     

水稻线粒体DNA热变性的动力学研究

作为重要的细胞器之一，线粒体有其自身的遗传系统，它不仅有其自身的基因组，也有其独立的转录、翻译系统，甚至其使用的遗传密码也与核基因不同．线粒体DNA（mtDNA）对于线粒体本身的生物发生意义重大，尽管大多数线粒体蛋白是由细胞核基因组编码，但线粒体DNA仍有10％左右的     

Effect of the Coating of the Polymer Blend (Polyacrylamide/PEG 6000) on the Efficiency of Rice Husk as a Pesticide Carrier

In recent years the utilization of fibers and powders derived from agricultural sources has become a subject of interest. However, they have been exploited only from an engineering point of view, and the strong ability of agricultural wastes as a carrier for agrochemical formulations has been ignored. A study has been made on the possibility of using such an agrochemical waste, namely rice husk, which is readily available and biodegradable, as a carrier for pesticide formulation. The solid formulations were prepared by adsorbing deltamethrin on the rice husk. The deltamethrin‐adsorbed rice husk is then coated with the polymer blend of Polyacrylamide and PEG 6000 in varying ratios between the deltamethrin‐adsorbed rice husk and the polymer blend. The formulations were characterized by analytical methods such as FTIR and XRD techniques. Important physical properties from the formulation standpoint, such as solubility, dispersion stability, and wettability, were studied.     

Impact of Milling on Rice Constituents (Oryza Sativa L.): A Metabolomic Approach

Milling is an influential factor that affects the nutritional components in rice. However, the alteration of rice constituents by milling has not been thoroughly examined. In this study, rice with various degrees of milling was analyzed by gas chromatography–mass spectrometry and high-performance liquid chromatography–mass spectrometry. Principal component analysis and partial least square-discriminant analysis were performed to characterize the nutritional components that have significant changes during milling. The concentrations of sugars and sugar alcohols decreased while the phospholipids increased in accordance with the milling degree. These results provide a contrast to the common idea that brown rice is nutritionally superior to white rice. In conclusion, the knowledge of nutritional alterations related to milling may benefit rice production and consumption.     

Analytical methods for pesticide residues in rice

Rice consumption has increased worldwide over recent decades, as it has become one of the most common foods. Although the analysis of environmental samples coming from rice areas has been well documented, there is less information regarding the analysis of pesticide residues in rice-grain samples.Rice (paddy, brown and white) can be considered a complex matrix, leading to difficulties in the application of the different multiresidue methods described in the literature. This review addresses and compares the principal extraction and clean-up methodologies [e.g., liquid-liquid extraction, solid-phase extraction, pressurized-liquid extraction, QuEChERS (quick, easy, cheap, effective, rugged and safe), gel-permeation chromatography and supercritical-fluid extraction - with QuEChERS-based methods being the most frequently employed].Traditionally, the determination of pesticide residues in rice has been based on gas chromatography with mass spectrometry (MS). But the application of new classes of pesticides has driven laboratories to increase the use of liquid chromatography with tandem MS. The limits of detection and quantification are in the ranges 0.09-90 μg/kg and 1-297 μg/kg, respectively, for the methodologies reported. These values agree with the current internationally-accepted maximum residue limits (MRLs).Based on the European Union (EU) database, more than 3000 analyses of pesticide residues in rice have been performed by official EU laboratories over the past decade. Of these, 6% reported pesticide residues above the MRLs.Physico-chemical properties can explain the occurrence of pesticides in rice commodities: lipophilic pesticides are frequently found in brown rice, whereas fungicides are mainly found in milled rice. Carbendazim, malathion, iprodione, tebuconazole, quinclorac and tricyclazole are the pesticides most frequently found in white rice, while buprofezin, hexaconazole, chlorpyrifos and edifenphos are most commonly found in paddy rice.Pesticide-residue concentrations can be affected during rice processing - with concentrations generally lower in the final products. However, few studies focusing on primary processing have addressed the setting of precise values applicable for the processing factors.     

量热法研究线粒体代谢的热力学和动力学行为

线粒体是细胞中极为重要的细胞器，是产生细胞所必需的“富能”物质ATP的重要场所，为细胞活动提供所需化学能．在生命体能量代谢过程中除一部分能量用于合成ATP外，其余则以热的形式释出．用精密热量计测出线粒体代谢过程中的热量输出对了解线粒体的功能和代谢机制具有十分重要的意义．用微量热法研究线粒体体外代谢已有一些报导［‘，’］．本工作用精密热量计和差式扫描量热仪侧定了水稻线粒体体外代谢热谱和DSC曲线，计算了水稻线粒体活性增长速率常数，比较了不同保藏时间的水稻线粒体体外代谢的差异，并初步探讨了水稻线粒体在变…     

A Review of Red Yeast Rice,a Traditional Fermented Food in Japan and East Asia: Its Characteristic Ingredients and Application in the Maintenance and Improvement of Health in Lipid Metabolism and the Circulatory System

Red yeast rice has been used to produce alcoholic beverages and various fermented foods in China and Korea since ancient times; it has also been used to produce tofuyo (Okinawan-style fermented tofu) in Japan since the 18th century. Recently, monacolin K (lovastatin) which has cholesterol-lowering effects, was found in some strains of Monascus fungi. Since statins have been used world-wide as a cholesterol-lowering agent, processed foods containing natural statins are drawing attention as materials for primary prevention of life-style related diseases. In recent years, large-scale commercial production of red yeast rice using traditional solid-state fermentation has become possible, and various useful materials, including a variety of monascus pigments (polyketides) that spread as natural pigments, in addition to statins, are produced in the fermentation process. Red yeast rice has a lot of potential as a medicinal food. In this paper, we describe the history of red yeast rice as food, especially in Japan and East Asia, its production methods, use, and the ingredients with pharmacological activity. We then review evidence of the beneficial effects of red yeast rice in improving lipid metabolism and the circulatory system and its safety as a functional food.     

Application studies of activated carbon derived from rice husks produced by chemical-thermal process--a review

The production of functional activated carbon materials starting from cheap natural precursors using environmentally friendly processes is a highly attractive subject in material chemistry today. Recently, much attention has been focused on the use of plant biomass to produce functional carbonaceous materials, encompassing economic, environmental and social issues. Besides the classical route to produce activated carbons from fossil materials, rice husk shows clear advantages in that it can generate a variety of cheap and sustainable carbonaceous materials with attractive nanostructure and functional patterns for a wide range of applications. From a comprehensive literature review, it was found that porous carbon that derived from rice husks, in addition to having wide availability, has fast kinetics and appreciable adsorption capacities too. Porous carbon materials also play a significant role in new applications such as catalytic supports, battery electrodes, capacitors, and gas storage. In this review, an extensive list of rice husks literature has been compiled. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.     

Rice proteomics: current status and future perspectives

Rice, the first cereal crop genome to be decoded, has attracted the attention of researchers worldwide because of its immense socio-economic impact on human existence. With the availability of the draft genome sequence of two major types, japonica- and indica-rice, "rice proteomics" has entered into the era of functional genomics. Although during the last decade an important but limited progress (mainly construction of protein datafiles) has been made in the field of rice proteomics, it is only recently that dedicated research groups have taken this challenge to systematically analyze the rice proteome at the cell (and organelle), tissue, and whole plant level. Important gains achieved by the accelerated technological progress in protein separation and identification will help in going beyond the simple cataloguing of rice proteins in realistic terms. In this review, we discuss the progress made in the field of rice proteomics to date and dwell upon the future direction/problems/approaches towards defining the rice proteome.     

Identification and determination of naturally occurring folates in grains of rice (Oryza sativa L.) by UPLC-MS/MS analysis

The genetic potential and biofortification of India-grown rice with bioavailable folate has not been studied yet. The objectives of this study were to determine the folates concentration in four cultivars of rice through UPLC–MS/MS. Total folate concentration in rice cultivars ranged from 11.0 to 51 μg/100 g with a mean of 26.0 μg/100 g. Among the four rice cultivars, the pigmented grain cultivar Nootripathu possesses two-fold rich sources of total folates than the other three non-pigmented grain cultivars. The average value of 100 g serving of rice grains could provide the amount of recommended daily allowance (% RDA) of dietary folates (6.5%) for adults, which ranged from 2.7–12.7%. Among the 5 individual forms of folates, 5-methyltetrahydrofolate was most abundant in rice cultivars followed by 10-Formylfolic acid and folic acid. The result of this study has been useful for biofortification of folates in rice.     

Isolation of rice allergenic cDNA clones from a rice cDNA library by immunoscreening with a polyclonal antibody specific to 16 kD rice allergenic protein

Clinical cases of type-1 hypersensitive reaction to rice (Oryza sativa) have been reported in western countries as well as in Japan. Among rice proteins, 14-16 kD globulin proteins encoded by multiple gene family have been identified as major rice allergens. In this study, a rice cDNA library was constructed using lambda UniZap vector and screened with a rat anti-16 kD globulin protein polyclonal antibody in order to isolate Korean rice allergenic cDNA clones. Five independent cDNA clones, termed RAK1-5, were obtained after second rounds of plaque assay and immunoblot analysis. These clones encoded 13-19 kD recombinant proteins upon IPTG induction, which were identified by the polyclonal antibody in immunoblot analysis. DNA sequencing analysis showed that RAK1-4 have 99% sequence homology with RA5b, and RAK5 is closely related with RA14c. This result indicated that RA5b gene is widely distributed in our cDNA library among other possible rice allergenic genes, and more study is needed to isolate heterogeneous or novel rice allergen genes.     

Studies on potential utilization of rice husk char in blend with lignite for cocombustion application

Combustion behavior of Indian lignite sample blended with rice husk chars (prepared at low temperature) has been examined in this study through simultaneous differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) technique. Range of inputs obtainable by characteristic TG–DSC parameters has been utilized to arrive at important conclusions and observations in respect of ideal selection of blend proportion, proper utilization of the blend combination, etc. Deviations of experimental mass loss pattern (TG) and of rate curve (DTG) from corresponding expected theoretically calculated pattern have also been noted for different blends to examine possible advantageous or disadvantageous effects. As per the observations recorded, use of biomass char in blends (with lignite) was found to be very much beneficial and its proportion in the blends may be restricted to a level of 40 % by mass to extract maximum benefits in burning performance. This paper also focuses specific advantages of use of rice husk char in place of raw rice husk for cocombustion applications. Moreover, the importance of heat release pattern to assess compatibility of a fuel mix with existing boiler design and also to workout fresh boiler design for cocombustion application has been discussed in this paper.     

A normal phase HPTLC method for the quantitative determination of ochratoxin A in rice

Summary A previously published [1] liquid chromatographic method for the determination of ochratoxin A in corn, barley and kidney has been modified for application to parboiled rice with quantification by high performance thin layer chromatography (HPTLC). The method has been validated by spiking uncontaminated extracts of rice with ochratoxin A over the range 0 to 198 g kg^–1. The proposed method has some significant advantages over the current AOAC method [2], especially for determining low levels of ochratoxin A in parboiled rice.     

Action of rice bran phytase on hydrolysis of phytin

The hydrolytic activity of rice bran phytase in relation to phytin and other inositol phosphates has been studied. The maximum activity is exhibited at pH 5.2 and 50°C. Being present in a state of binding with hydrated phytin complexes, phytase hydrolyses endogenous phytin intensively. The affinity of the enzyme present in the form of the complex with exogenous sodium phytate is extremely low. The results of the investigation have provided the possibility of revealing the reasons for the quantitative change in the amount of phytin in rice bran as a function of the technological parameters of the heat treatment of the raw material and the extraction of inositol phosphates.     

Molecular phylogenetic study and expression analysis of ATP-binding cassette transporter gene family in Oryza sativa in response to salt stress

ATP-binding cassette (ABC) transporter is a large gene superfamily that utilizes the energy released from ATP hydrolysis for transporting myriad of substrates across the biological membranes. Although many investigations have been done on the structural and functional analysis of the ABC transporters in Oryza sativa, much less is known about molecular phylogenetic and global expression pattern of the complete ABC family in rice. In this study, we have carried out a comprehensive phylogenetic analysis constructing neighbor-joining and maximum-likelihood trees based on various statistical methods of different ABC protein subfamily of five plant lineages including Chlamydomonas reinhardtii (green algae), Physcomitrella patens (moss), Selaginella moellendorffii (lycophyte), Arabidopsis thaliana (dicot) and O. sativa (monocot) to explore the origin and evolutionary patterns of these ABC genes. We have identified several conserved motifs in nucleotide binding domain (NBD) of ABC proteins among all plant lineages during evolution. Amongst the different ABC protein subfamilies, ‘ABCE’ has not yet been identified in lower plant genomes (algae, moss and lycophytes). The result indicated that gene duplication and diversification process acted upon these genes as a major operative force creating new groups and subgroups and functional divergence during evolution. We have demonstrated that rice ABCI subfamily consists of only half size transporters that represented highly dynamic members showing maximum sequence variations among the other rice ABC subfamilies. The evolutionary and the expression analysis contribute to a deep insight into the evolution and diversity of rice ABC proteins and their roles in response to salt stress that facilitate our further understanding on rice ABC transporters.     

MOLECULAR CHARACTERIZATION OF RICE Wx GENE

The complete nucleotide (nt) sequence of the rice waxy(Wx) gene, which is responsible for the synthesis of amylose in endosperm and pollen, has been determined by a combination of restriction mapping and nt sequence analysis of two overlapping genomic DNA clones. The entire gene is about 5.5 kb in length. The alignment of the nt sequence of the Wx gene from rice with those of maize (Klsgen, R. B. et al.) and barley (Rohde, W. et al.) revealed the presence of thirteen introns and fourteen exons. The full-length of Wx protein in cluding transit peptide is 609 amino acid (aa) residues. The calculated molecular weight of rice Wx preprotein is about 72 kD. There is no significant difference between the similarity scores of the aa sequence deduced from the rice Wx gene compared with those of maize and barley. However, the nt sequences of the 5'-end upstream, 3'-end downstream and introns of the rice Wx gene, as well as the aa sequence of the transit peptide region of the Wx preprotein have low similarity scor     

Solvent-induced morphological transition in core-cross-linked block copolymer micelles

Microwave-assisted polymerization has been utilized to synthesize amphiphilic poly(2-ethyl-2-oxazoline-block-2-"soy alkyl"-2-oxazoline) diblock copolymers (PEtOx-PSoyOx). The amphiphilic block copolymers have been used to prepare aqueous spherical micelles consisting of a PEtOx corona and a PSoyOx core, which have been further cross-linked by UV irradiation. The morphology of these cross-linked micelles has been shown to reversibly change from spheres to short rods referred to as rice grains whenever the micelles were transferred from water into acetone, a nonselective solvent for the constituent blocks. This morphological transition has been attributed to the swelling of the slightly cross-linked PSoyOx core.     

Electron beam treatment parameters for control of stored product insects

The fluidized bed process (EBFB) has been evaluated for the disinfestation of cereal grains. The various life stages from egg to adult have been studied on the 225 kV pilot as a function of surface dose. Three of the most common pests were selected: the rice weevil (S. oryzae), the lesser grain borer (R. dominica) and the red flour beetle (T. castaneum). The major challenge to this process lies in those “protected” life-stages active deeply within the endosperm of the grain kernel. The rice weevil is such an internal feeder in which the larvae develop through several molts during several weeks before pupation and adult emergence. Product velocities up to 2000 m/min have been used for infested hard winter wheat at dose levels up to 1000 Gy. Detailed depth of penetration studies at three life stages of S. oryzae larvae were conducted at 225–700 kV and demonstrated effective mortality at 400 kV×200 Gy. Mortality data are also presented for the radiation labile eggs of these insects as well as the (sterile) adults, which typically lived for several weeks before death. These results are compared with earlier ⁶⁰Co gamma-ray studies on these same insects. Based upon these studies, the effectiveness of the fluidized bed process employing self-shielded electron beam equipment for insect control in wheat/rice at sub-kilogray dose levels has been demonstrated.