Analysis of phenolic compounds in white rice, brown rice, and germinated brown rice

Two hydroxycinnamate sucrose esters, 6'-O-(E)-feruloylsucrose and 6'-O-(E)-sinapoylsucrose, were isolated from methanol extracts of rice bran. Soluble and insoluble phenolic compounds as well as 6'-O-(E)-feruloylsucrose and 6'-O-(E)-sinapoylsucrose from white rice, brown rice, and germinated brown rice were analyzed using HPLC. The results demonstrated that the content of insoluble phenolic compounds was significantly higher than that of soluble phenolics in rice, whereas almost all compounds identified in germinated brown rice and brown rice were more abundant than those in white rice. 6'-O-(E)-Feruloylsucrose (1.09 mg/100 g of flour) and 6'-O-(E)-sinapoylsucrose (0.41 mg/100 g of flour) were found to be the major soluble phenolic compounds in brown rice. During germination, an approximately 70% decrease was observed in the content of the two hydroxycinnamate sucrose esters, whereas free phenolic acid content increased significantly; the ferulic acid content of brown rice (0.32 mg/100 g of flour) increased to 0.48 mg/100 g of flour and became the most abundant phenolic compound in germinated brown rice. The content of sinapinic acid increased to 0.21 mg/100 g of flour, which is nearly 10 times as much as that in brown rice (0.02 mg/100 g of flour). In addition, the total content of insoluble phenolic compounds increased from 18.47 mg/100 g of flour in brown rice to 24.78 mg/100 g of flour in germinated brown rice. These data suggest that appropriate germination of brown rice may be a method to improve health-related benefits.     

Effect of zinc sulfate fortification in germinated brown rice on seed zinc concentration, bioavailability, and seed germination

Rice is the staple food for more than half of the world's population and, hence, the main source of a vital micronutrient, zinc (Zn). Unfortunately, the bioavailability of Zn from rice is very low not only due to low content but also due to the presence of some antinutrients such as phytic acid. We investigated the effect of germination and Zn fortification treatment on Zn bioavailability of brown rice from three widely grown cultivars using the Caco-2 cell model to find a suitable fortification level for producing germinated brown rice. The results of this study showed that Zn content in brown rice increased significantly (p < 0.05) as the external Zn concentrations increased from 25 to 250 mg/L. In contrast, no significant influence (p > 0.05) on germination percentage of rice was observed when the Zn supply was lower than 150 mg/L. Zn fortification during the germination process has a significant impact on the Zn content and finally Zn bioavailability. These findings may result from the lower molar ratio of phytic acid to Zn and higher Zn content in Zn fortified germinated brown rice, leading to more bioavailable Zn. Likewise, a significant difference (p < 0.05) was found among cultivars with respect to the capacity for Zn accumulation and Zn bioavailability; these results might be attributed to the difference in the molar ratio of phytic acid to Zn and the concentration of Zn among the cultivars evaluated. Based on global intake of Zn among the world population, we recommend germinated brown rice fortified with 100 mg/L ZnSO(4) as a suitable concentration to use in the germination process, which contains high Zn concentration and Zn bioavailability. In the current study, the cultivar Bing91185 fortified with Zn through the germination process contained a high amount as well as bioavailable Zn, which was identified as the most promising cultivar for further evaluation to determine its efficiency as an improved source of Zn for target populations.     

Shoot and root growth of rice seedlings as affected by soil and foliar zinc applications

Abstract

The present study investigated how foliar zinc (Zn) application affects seedling growth and Zn concentration of rice grown in a Zn-deficient calcareous soil with different soil Zn treatments. Seeds were sown in soil with five rates of Zn (0, 0.02, 0.1, 0.5 and 5.0?mg kg^?1 soil) with and without foliar application of 0.5% ZnSO₄. Seedlings were harvested at 35?days and separated into (i) the youngest leaves, (ii) the remaining shoot parts and (iii) roots. In soil with no Zn supply, shoot and root dry weight of the rice seedlings were significantly increased by foliar and soil Zn treatments. Plant growth was not clearly increased in low soil Zn treatments, while at each soil Zn treatment, foliar Zn application promoted growth of plants. Plants with adequate Zn supply had the highest Zn concentrations in the youngest leaf. Foliar Zn spray improved Zn concentration of the new growth formed after foliar spraying which shows that Zn is phloem mobile and moved from treated leaves into youngest new leaves. The results indicate clearly in rice seedlings that shoot growth shows more responsive to low Zn than the root growth. The results obtained in the present study are of great interest for proper rice growth in Zn-deficient calcareous soils but needs to be confirmed in other rice genotypes.     

Effect of calcium and magnesium on 65zinc absorption and translocation in rice seedlings

Effect of calcium and magnesium on zinc absorption by 21‐day‐old rice seedlings and its translocation within the plants was studied in the nutrient solution culture using radioactive zinc. The concentrations of the elements in the nutrient solution were 0.5, 1.0 and 2.0 μM zinc and 0, 10 and 20 mM calcium and magnesium. Absorption of ⁶⁵zinc was studied for 30, 60 and 90 minutes and translocation for 24 hours. Zinc absorption increased with time and increased zinc concentration in the nutrient solutions. Addition of calcium and magnesium reduced zinc absorption by rice seedlings by about 60 and 90% respectively at a concentration of 20 mM. The nature of inhibition of both calcium and magnesium on zinc was non‐competitive as indicated by Michaelis constants. A large fraction of zinc absorbed remained in roots and only 5.3% was translocated to shoots even at 2.0 #GMM zinc concentrations in solution. The effect of cations on translocation of ⁶⁵zinc within rice seedlings was more at lower( 0.5 μM zinc) than at higher (2.0 μM zinc) concentrations.     

Interaction between manganese and zinc in growth of rice plants

Many instances of antagonistic relationships among various micro-elements and between micro- and macro-elements in their absorption, translocation, and functions in plant growth have been reported (1). In a series of our researches on the effect of micro-elements on the growth of rice plants, it was observed that manganese toxicity symptom of rice plants was markedly reduced by increasing the concentration of zinc in the nutrient sdution. Although it has been reported that manganese toxicity symptoms of crops were reduced by addition of Fe (2,3), A1 (4), Ca (5) and silicate (6) to the medium, there have been few reports of the effect of Zn on Mn toxicity of rice plants. In this paper, the interaction between Mn and Zn in the growth of rice plants was reported.     

Influence of growth temperature on the amounts of tocopherols, tocotrienols, and gamma-oryzanol in brown rice

Brown rice is a valuable source of lipid-soluble antioxidants including ferulated phytosterols (i.e., gamma-oryzanol), tocopherols, and tocotrienols. To evaluate the impact of temperature on the accumulation of these compounds, seeds from six different rice lines grown to maturity in replicate greenhouses in Gainesville, FL, were analyzed. The lines represented Oryza sativa indica, O. sativa japonica, and Oryza glaberrima of different origins. Temperatures were maintained near ambient at one end of each greenhouse and at approximately 4.5 degrees C above ambient at the other end. gamma-Oryzanols, tocopherols, and tocotrienols were extracted from whole seed (i.e., brown rice) and analyzed by HPLC. Tocotrienols and tocopherols varied widely between lines but changed only slightly with respect to temperature. In general, the proportions of alpha-tocotrienol and/or alpha-tocopherol increased at elevated temperature, whereas gamma-tocopherol and gamma-tocotrienol decreased. Six gamma-oryzanol peaks, identified on the basis of absorbance maxima at 330 nm and HPLC-mass spectrometry, were quantified. The most abundant component was 24-methylenecycloartanyl ferulate, present at 40-62% of total. Its levels increased 35-57% at elevated temperature in five of six lines, accounting for most of the change in total gamma-oryzanol. The results suggest that the physiological action of individual ferulated phytosterols should be investigated because their relative proportions in gamma-oryzanol can change.     

Detection of changes in taste of japonica and indica brown and milled rice (Oryza sativa L.) during storage using physicochemical analyses and a taste sensing system

Changes in the taste of japonica, hybrid, and indica brown and milled rice, stored for 10 months at low (5 degrees C, 65-70% relative humidity) and room temperatures were observed by physicochemical analyses and a novel method using a taste sensing system. During storage, some properties increased or decreased while others were fairly constant. The main taste components of cooked rice such as sweetness (sucrose) and umami tastes (glutamic acid and aspartic acid) were reduced during storage, whereas glucose and fructose increased. The increase of fat acidity and consequent decrease of the pH value of the cooking solution may contribute to the off-taste of cooked stored rice. A taste sensing system with 10 lipid membrane sensors was also used to classify new and old rice samples using principal component analysis. Fresh and room temperature stored japonica and indica rice could be clearly distinguished; however, it was not possible to differentiate the samples stored at low temperature.     

Odor-active compounds in cooked rice cultivars from Camargue (France) analyzed by GC-O and GC-MS

Volatile compounds of cooked rice from scented (Aychade, Fidji) and nonscented (Ruille) cultivars grown in the Camargue area in France were compared to that of a marketed Asian scented one (Thai) by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). GC-O analyses of the organic extracts resulted in the perception of 40 odorous compounds. Only two compounds, oct-1-en-3-one and 2-acetyl-1-pyrroline, were almost always perceived. Hierarchical cluster analysis showed that most of the difference between rice odors was linked to quantitative differences with only 11 compounds being specific to some of the rice. Sixty compounds were identified and quantified by GC-MS, including a few new odor-active components. Principal component analysis enabled us to differentiate scented cultivars from a nonscented one, and scented rice cultivars from Camargue from a Thai sample. Calculated odor-active values evidenced that the Thai sample odor differed from that of scented Camargue cultivars because of the degradation of lipids and of cinnamic acid compounds.     

Simple analytical method for organophosphorus pesticide determination in unpolished rice, using removal of fats by zinc acetate

A rapid and simple method is developed for the determination of organophosphorus pesticides in unpolished rice. The new method incorporated acetonitrile-water (1 + 1) extraction, removal of fats by zinc acetate, and further cleanup on an activated charcoal chromatographic column. The higher fatty acids in the extract react rapidly with zinc acetate to form insoluble zinc carboxylates, which precipitate. Additional interferences were cleaned up on an activated charcoal chromatographic column, and organophosphorus pesticides adsorbed on the activated charcoal were eluted with acetone-hexane. Dimethoate is not retained on the activated charcoal and must be extracted with dichloromethane from the first acetonitrile-water eluate. Pesticides are measured by flame photometric gas chromatography. Recoveries from 50 g unpolished rice samples fortified with 5-50 micrograms diazinon, 6-30 micrograms parathion, 8-40 micrograms fenitrothion and IBP, 10-50 micrograms dimethoate and fenthoate, 20-100 micrograms malathion, or 40-200 micrograms EPN ranged from 75.7 to 95.8%.     

Bioavailability and efficacy of vitamin D2 from UV-irradiated yeast in growing, vitamin D-deficient rats

New food sources are needed to bridge the gap between vitamin D intake and recommended intake. We assessed the bioavailability and efficacy of vitamin D in an 8 week dose-response study of bread made with vitamin D2-rich yeast compared to vitamin D3 in growing, vitamin D-deficient rats. Plasma 25-hydroxyvitamin D (25OHD) levels increased in a curvilinear, dose-dependent manner with both forms of vitamin D, but rats fed vitamin D2-rich yeast achieved lower levels than rats fed vitamin D3. Rats fed the highest doses of vitamin D had significantly greater (p<0.05) trabecular BMC, BMD, bone volume, and connectivity density, and greater midshaft total cross-sectional area, compared to rats on the vitamin D-deficient diets, with no significant difference due to vitamin D source. Vitamin D2-rich yeast baked into bread is bioavailable and improves bone quality in vitamin D-deficient animals.     

Uptake of iron,zinc, manganese,and copper by seedlings of hybrid and traditional rice cultivars from different soil types 1

In pot experiments, uptake of zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) by hybrid rice from different soil types was compared with a traditional rice (Oryza sativa L.) cultivar. The concentration and total uptake of Fe in the shoots of hybrid rice grown in Oxisol and Ultisol were lower than those of the traditional cultivar. The concentration and total uptake of Zn in the shoots of hybrid rice grown in the Inceptisol (calcareous) were significantly higher than those of the traditional cultivar. Higher ratios of Zn and Fe in upper leaves (UL) to the lower leaves (LL) were found in hybrid rice grown in the calcareous Zn‐deficiency soil. The results indicated that hybrid rice root avoided absorbing excess Fe from Fe‐toxic soils due to its higher oxidizing power, and was more efficient in absorbing Zn from calcareous Zn‐deficient soils than the traditional cultivar.     

Interaction effect of nitrogen,phosphorus, and zinc fertilization on growth,yield, and nutrient contents of aromatic rice varieties

Abstract

Studies on nutrient interactions in aromatic rice are needed for proper understanding of impact of imbalanced use of nutrients in the era of multi and micro-nutrient deficiencies. A pot experiment was conducted during the rainy/wet season (June–October) of 2013 at New Delhi, to study the interaction effects of two levels each of nitrogen (N) (0 and 120?kg?ha^?1), phosphorus (P; 0 and 25.8?kg?ha^?1), and zinc (Zn; 0 and 5?kg?ha^?1) in two aromatic rice (Oryza sativa L.) varieties, viz. Pusa Rice Hybrid 10 and Pusa Basmati 1121. Application of N, P, and Zn resulted in increase of dry matter (0.91, 0.32, and 0.24?g plant^?1, respectively) 60?days after sowing (DAS) and grain yield of rice (3.68, 1.67, and 1.17?g plant^?1). The increase in yield of rice owing to N application was relatively higher by 0.98, 0.22, and 1.05?g plant^?1, respectively, when either P or Zn or both were applied with N than alone application of N, indicating synergetic effect of P and Zn application with N. The higher concentration and uptake of K in grain (0.25% vs 0.10%) and straw (1.32% vs 0.94%) were observed in the treatment received N than no N, though K was applied uniformly in all the treatments. It indicates positive interaction of N and K. The higher uptake of P in grain and straw was observed when P was applied with N and Zn (3.34 and 2.15?mg plant^?1), or with N (3.26 and 2.11?mg plant^?1) signifying positive effect of N on P uptake in rice.     

Nitrogen nutrition and use efficiency in rice as influenced by crop establishment methods,cyanobacterial and phosphate solubilizing bacterial consortia and zinc fertilization

ABSTRACT

A field experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during wet season of 2013 and 2014, involving three crop establishment methods (CEMs) viz. puddled transplanted rice (PTR), system of rice intensification (SRI), and aerobic rice system (ARS). Three rates of nitrogen (N) and phosphorus (P) application (0%, 75%, and 100% of recommended dose of N and P) (RDN) (120 kg N ha^–1 and 25.8 kg P ha^–1) and two sources of N and P (fertilizer and cyanobacterial-bacterial inoculation) were tested with and without zinc (Zn) fertilization in all CEMs. The concentration of N in PTR and SRI was significantly higher than ARS with higher uptake of 10.3 and 11.1 kg ha^–1 in PTR and SRI over ARS. Treatment with 100% RDN led to significantly higher N availability and uptake than 75% RDN and absolute control, i.e. 14.5 and 32.0 kg ha^–1, respectively. Application of Anabaena-Pseudomonas biofilm formulation (MC2) in conjunction with 75% RDN increased total uptake of N by 12.7 kg ha^–1 compared to 75% RDN only. A positive correlation was found between N concentration and acetylene reductase activity at 70 days after sowing (DAS) (R² = 0.52) and 100 DAS (R² = 0.38) based on mean of 2 years study. Zn fertilization significantly increased N concentration in rice straw and milled rice irrespective of the crop establishment methods. Our study signifies the importance of microbial inoculation, optimal N fertilization along with SRI and PTR as more effective crop establishment methods for deriving greater benefits in terms of N nutrition in rice.     

Differences in silica release from soils of two Scottish associations as assessed by trimethylsilylation

The amounts of monomeric silica released on trimethylsilylation of a range of Soil Groups of the Darleith Soil Association, developed on glacial till derived from Carboniferous age lavas of basic and intermediate composition, is significantly higher than the amounts released from corresponding Soil Groups of the Lauder Soil Association, developed on glacial till derived from Devonian age conglomerates and sandstone. Monoremic silica release values for the leached soils within an association are, in general, higher than those of the gley soils. For all soil profiles the eluvial horizon released the smallest amount of monomeric silica with the maximum amount being released, in most instances, from the illuvial horizon. Ferromagnesian minerals and crystalline clay minerals, in particular vermiculite and chlorite in the Darleith Association soils, release monomeric silica under acid conditions. For both the Darleith and Lauder Association soils the principal source of monosilicic acid is thought to be aluminosilica gel of low Si:A1 ratio.     

籼型三系杂交稻稻米中重金属镉含量的杂种负优势效应及配合力、遗传力分析

本文采用5 个不育系与6 个恢复系进行不完全双列杂交。从配制的杂交组合中选择30 个生育期基本一致的组合, 研究籼型杂交稻稻米中重金属Cd 含量的杂种优势表现及配合力、遗传力。结果表明: 稻米中Cd 含量有明显的杂种负优势效应; 不育系和恢复系稻米中Cd 含量的一般配合力效应及二者的特殊配合力效应均达极显著水平, 说明低Cd 含量组合的选育中双亲的遗传改良和组合的评价筛选都很重要。Cd 含量的广义遗传力与狭义遗传力均较高、且相差较小, 分别为97.73%和80.10%, 说明稻米Cd 含量以基因加性作用为主, 亲本改良在早期世代选择的效果较好。     

Sorption of lead,copper, zinc,and cadmium by soils: effect of nitriloacetic acid on metal retention

Abstract

Laboratory experiments were carried out to evaluate lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) sorption‐desorption by three soils of contrasting characteristics. Talamanca (silt loam, montmorillonite, Calcic Haploxeralfs), Mazowe (clay, kaolinite, Rhodic Kandiustalf), and Realejos (sandy silt loam, allophane, Typic Hapludands). A second objective was to study the effect of nitriloacetic acid (NTA) on the sorption process. The Talamanca soil, which had a native pH of 6.4 and presented the highest effective cation exchange capacity (ECEC), sorbed more of each of the metal tested than did the other two soils. When the other two soils were compared metal sorption was also related to pH and ECEC. The very low sorption capacity showed by Realejos may be attributed to the low net surface negative charge density of this soil, arising from its allophanic nature. A common feature of the three soils was the relative strong sorption of both Pb and Cu relative to Cd and Zn with Pb showing the highest sorption levels. The selectivity sequences of metals retention were Pb>Cu>Zn>Cd for Talamanca soil, Pb>Cu>Zn≈Cd for Mazowe, and Pb>Cu>Cd>Zn for Realejos. Metal desorption values were low. The order of metal desorption (Cd≈Zn>Cu>Pb) was the same for the three soils studied. Quantitative differences observed in the extractability of the sorbed metals between the soils (Realejos>Mazowe>Talamanca) indicated that soil properties which enhanced metal sorption contributed at the same time to slow down the backward reaction. The addition of NTA to the soil suspension significantly depressed metal sorption by the three soils investigated. Compared with the free ligand system Pb, Cu, Zn, and Cd sorption in the presence of NTA decreased roughly 50%.     

分层供水和表层施锌对玉米植株生长和锌吸收的影响

进行分层水分隔离盆栽试验,模拟田间不同层次土壤中水分含量分布不均条件,研究表层土壤施锌情况下,玉米植株生长和锌吸收以及根系在表层和底层土壤中的分配。结果表明,施锌明显促进了玉米地上部生长。在土壤表层水分充足时,施锌对植株增长效果较明显,有利于玉米利用土壤水分。缺锌条件下,改善土壤水分并未显著提高玉米生物量。表层土壤干旱时,上下层土壤中根系干物重之比减小,底层土壤中根系分布相对增加,当表层土壤水分增加时,根系在表层土壤中干物重显著增加,分布相对增多。施锌并没有影响根系在不同层次土壤中的分配。表层土壤水分对苗期玉米植株锌吸收总量有显著影响,干旱条件下,玉米植株锌吸收总量下降;底层土壤水分供应状况对玉米锌浓度影响不大,但植株中锌向地上部运转增加。尽管施锌没有提高生长早期玉米根系生长和对底层土壤水分的利用,但本研究表明缺锌旱地土壤上如通过灌溉等措施增加了耕层土壤水分,应该注意施用锌肥,否则严重影响玉米生物量和玉米对土壤水分的利用效率。     

Effect of different foliar zinc application at different growth stages on seed zinc concentration and its impact on seedling vigor in rice

This study evaluated how zinc (Zn) concentration of rice (Oryza sativa L.) seed may be increased and subsequent seedling growth improved by foliar Zn application. Eight foliar Zn treatments of 0.5% zinc sulfate (ZnSO₄?·?7H₂O) were applied to the rice plant at different growth stages. The resulting seeds were germinated to evaluate effects of seed Zn on seedling growth. Foliar Zn increased paddy Zn concentration only when applied after flowering, with larger increases when applications were repeated. The largest increases of up to ten-fold were in the husk, and smaller increases in brown rice Zn. In the first few days of germination, seedlings from seeds with 42 to 67?mg Zn?kg^?1 had longer roots and coleoptiles than those from seeds with 18?mg Zn?kg^?1, but this effect disappeared later. The benefit of high seed Zn in seedling growth is also indicated by a positive correlation between Zn concentration in germinating seeds and the combined roots and shoot dry weight (r?=?0.55, p?相似文献   

云南思茅和开远稻褐飞虱致害特性比较

对云南思茅和开远的稻褐飞虱致害特性研究结果表明,思茅和开远虫源在群体测定时分别表现为孟加拉型和生物型Ⅱ的致害特征。开远稻褐飞虱若虫在IR36、ASD7上的存活率均小于38．00％;思茅虫源在IR36、ASD7上的存活率均大于52．00％。若虫发育历期,开远虫源在Rathu Heenati上最长,而思茅虫源在Ptb33上最长,两地虫源在TN1、IR26、Mudgo、ASD7上均差异不显著。开远和思茅的稻褐飞虱若虫对不同品种具有不同的取食选择性。若虫取食的选择性同其对不同品种的致害性的表现并非完全一致。结果说明思茅和开远稻褐飞虱的致害特性不一样。两地稻褐飞虱可能来自不同虫源地。