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Highlights • The total As varied by two orders of magnitude (<2.6 µg/kg to 630 µg/kg). • Cd content was always below the maximum limit established by regulatory authorities. • Upland rice from Mato Grosso contain the lowest ever measured As contents. • Brazilian rice from flooded system contains iAs from 68 to 174 µg/kg. • Twenty samples were above the limit of iAs in rice destined to food for infants. Abstract Brazil is a major producer of rice, but there is not enough information about As and Cd in rice grown under different conditions in this country. Here, As and Cd were determined by ICP-MS and species of As by HPLC-ICP-MS in Brazilian husked rice, covering diverse cultivars and regions, as well as upland and flooded production systems. Significant differences were observed for contents of both elements according to the origin of rice. All samples were below the maximum limit for Cd (400 µg/kg) set by national legislation, while nine samples presented total As above the legislation limit (300 µg/kg). From 24 samples analyzed for As species, 42% showed iAs above the European limit for production of food to infants (100 µg/kg). The total As content in samples from Mato Grosso state presented a maximum value of 6 µg/kg, which combined with low Cd content make interesting further studies. [ABSTRACT FROM AUTHOR]

Abstract The research was done to analyze the seven different Traditional rice cultivars for their several functional structural and sensory properties. These cultivars were found to score highest as compared to hybrids rice varieties grown in the same regions in terms of sensory and other functional attributes. The moisture, protein, ash, fibre and carbohydrate content varied from 10.84% to 13.18%, 7.25–8.85%, 0.57–1.57%, 0.74–1.67% and 74.76–78.24%. Maximum Paste stability was depicted by these cultivars. The hardness of the rice gels were found to correlate positively with the fat content of their respective cultivars. The gelatinization enthalpy that indicates loss of double helical structure was found highest in Mushki budgi (9.73Jg−1). The granules with pentagonal structure were displayed by Mushki kandi with 3.70–6.74 µm length range. The X-ray diffraction patterns of the rice cultivars depicted A-type XRD pattern. The pigmented cultivars retained pigments upon cooking justified their health benefits in terms of antioxidants. The significance of this research is to analyse the cumulative effects of composition, granule morphology and crystalline pattern of rice cultivars on their several functional characteristics. [ABSTRACT FROM AUTHOR]

Highlights • Washing significantly reduced the vitamin B, mineral, and phytic acid in rice. • Rice cooking significantly decreased the thiamine, riboflavin, and PA contents. • MC was more effective than HC and NC of rice in terms of vitamin retention. • Mg, Fe, and Ca bioaccessibilities were increased after cooking. • Mn and Zn bioaccessibilities were decreased after cooking. Abstract The effects of washing, soaking, and cooking (ordinary cooking, high-pressure cooking, and microwave cooking) on thiamine, riboflavin, phytic acid (PA), and mineral contents (Mg, Ca, Mn, Zn, and Fe) of different cultivars rice, Xinfeng 2 and T-You 15, were investigated. Washing caused a significant loss in vitamin B, PA, and mineral contents, whereas, soaking only decreased the thiamine content. Moreover, cooking decreased the vitamin B and PA contents, and high-pressure cooking exerted more remarkable effects than those of ordinary and microwave cooking. Furthermore, washing and soaking increased the Zn and Ca bioaccessibilities, however, cooking improved the bioaccessibilities of Mg, Fe, and Ca, but decrease those of Zn and Mn. Therefore, vitamin and mineral losses caused by excessive washing should be given attention. Cooking processes in relatively low temperature may also be beneficial to the nutritive properties of vitamins and minerals. [ABSTRACT FROM AUTHOR]

Highlights • Toxic elements of cadmium and lead in rice were determined quantitatively using LIBS. • A simple and low cost sample pretreatment method named SLST was proposed. • Toxic elements in rice were prepared through ultrasound assisted extraction with hydrochloric acid solution. Abstract Stability and sensitivity of toxic elements determination is still unsatisfactory in agricultural product using laser-induced breakdown spectroscopy (LIBS). A simple and low cost sample pretreatment method named solid–liquid-solid transformation method was proposed in this work. The target analytes of cadmium (Cd) and lead (Pb) from rice samples were prepared through ultrasound assisted extraction in hydrochloric acid solution. The solution was dropped on the glass slide after centrifuging process and was further dried on a heater. Finally, the glass slide contained the analytes was carried out for LIBS determination. Compare with conventional pellet method, the spectral intensity of Cd and Pb element were enhanced significantly using LIBS. The limits of detection were 2.8 and 43.7 μg/kg, respectively. The limits of quantification were 9.3 and 145.7 μg/kg, respectively. The results demonstrated that LIBS coupled with ultrasound assisted extraction should be a promising tool to detect toxic elements in rice. [ABSTRACT FROM AUTHOR]

Highlights • Polishing and parboiling determine quantitative and qualitative variations. • Ca, Sr and Zn are more sensitive to parboiling than polishing. • Mg, Fe and Ba are more distributed in the outer layers. • Cu, Mo, Ni, As, Co and V were not determinants in grouping by processing types. • As, Cd and Pb concentrations were below the maximum allowed value. Abstract As major food staple, rice (Oryza sativa L.) is cultivated in irrigated fields absorbing widely trace elements wich may or may not migrate during processing types. Thus, we aimed to evaluate five national rice brands found in local market, in order to verify concentration of elements As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sn, Sr, V, Tl and Zn, presenting the differences and migration patterns between brown, parboiled and polished rice for each brand. Data were evaluated using ANOVA, post-hoc Tukey and PCA. The two major components presented 94.33% variance, indicating strong differentiation in samples by their processing types from their mineral composition. K is widely distributed over the grain, Mg, Fe and Ba are more distributed in the outer layers being more susceptible to loss, and Ca, Sr and Zn are more sensitive to the parboiling hydrothermal process. [ABSTRACT FROM AUTHOR]

An accurate method for the analysis of γ-aminobutyric acid (GABA) in rice grain was developed using trimethylsilyl (TMS) derivatization and stable isotope dilution gas chromatography-mass spectrometry. When this method was used with GABA‑d 6 as an internal standard (IS), the observed GABA concentration was maintained at 100% of the initial concentration with increasing storage time of the vial in the autosampler. In contrast, when using ribitol as an IS and multiple injections from one vial or single injections from different vials, the observed GABA concentration was 85 and 113% of the initial concentration upon increased storage time, respectively. The improved method recoveries at two different spike levels were between 93.3 and 97.8%, with relative standard deviations of less than 3.3%. The GABA content of resveratrol-enriched transgenic rice was compared with that of its non-transgenic counterpart from two field sites, and statistically non-significant differences were observed between the two grains. [ABSTRACT FROM AUTHOR]

The effects of degree of milling (DOM) between 0 and 8% on physico-chemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars were studied. Ash, protein, lipids and minerals decreased while blue value and crystallinity increased with increase in DOM. The colour parameters ( a ∗, b ∗) and cooking time (CT) decreased while L ∗(lightness) increased with increase in DOM. Elongation ratio (ER), gruel solid loss (GSL), length/breadth (L/B) and paste viscosities during cooking increased with increase in DOM. Short grain rice contained lower ash, protein, lipids, Mn, K, Ca, CT and GSL than long grain while the later showed higher crystallinity, Mn, P, K, Ca and ER. Paste and dough characteristics measured using Rheometer and Mixolab, respectively correlated well and differed with cultivar and DOM. Short and long grain cultivars showed variation in loss of different chemical constituents during varied DOM causing variation in cooking characteristics. [ABSTRACT FROM AUTHOR]

Immature rice grain is one of the underutilized by-products of paddy milling process. Despite its high potential of use as a food ingredient, it is mainly utilized as feed due to the rancidity problem. In the present study, the composition of immature rice grain, the potential of using infrared (IR) radiation for stabilization, and the effects of IR stabilization on color, fatty acid composition, tocopherol and γ-oryzanol contents of the grain were investigated. The free fatty acid (FFA) value of the unprocessed immature rice grain was 5.49% and increased to 35.71% at the end of 3 months of storage at room temperature. However, FFA content of the grains stabilized with IR radiation at specific conditions remained unchanged throughout the storage period. Moreover, IR stabilization did not caused a negative effect on the noted components of the immature rice grain. [ABSTRACT FROM AUTHOR]

Among cereals, rice is the second most cultivated staple crop in the world. It may be contaminated by toxic heavy metals present in water or soil. Therefore, monitoring the presence of heavy metals in rice and its products is a matter of a great importance from the nutritional and toxicological view. In this paper, a simple and effective analytical procedure based on dispersive micro solid-phase extraction with the use of oxidized multiwalled carbon nanotubes and batophenanthroline was developed for the determination of lead, cadmium, zinc, manganese and iron in white and wild rice samples. Due to the high preconcentration factor of 200, the optimized procedure allows obtaining detection limits between 0.13 and 0.35 ng mL −1 using flame atomic absorption spectrometry (FAAS). Novel preconcentration method can successfully be applied in food analysis with accuracy better than 7% rel. and repeatability lower than 3%. [ABSTRACT FROM AUTHOR]

Ionic liquid-based matrix solid phase dispersion-solvent flotation coupled with high performance liquid chromatography was developed for the determination of the acetanilide herbicides, including metazachlor, propanil, alachlor, propisochlor, pretilachlor, and butachlor in rice samples. Some experimental parameters, including the type of dispersant, the mass ratio of dispersant to sample, pH of sample solution, the type of extraction solvent, the type of ionic liquid, flotation time, and flow rate of N 2 were optimized. The average recoveries of the acetanilide herbicides at spiked concentrations of 50, 125, and 250 µg/kg ranged from 89.4% to 108.7%, and relative standard deviations were equal to or lower than 7.1%, the limits of quantification were in the range of 38.0 to 84.7 µg/kg. [ABSTRACT FROM AUTHOR]

Rice and rice products have been reported to contain high contents of toxic inorganic arsenic (iAs). The inorganic arsenic contents in microwavable ready-to-eat rice products (n = 30) and different types of Korean rice (n = 102) were determined by a gas chromatography-tandem mass spectrometry (GC–MS/MS). The method showed low limit of detection (0.015 pg), high intra- and inter-day repeatability (<7.3%, RSD), and recovery rates (90–117%). The mean iAs content in the ready-to-eat rice products was 59 μg kg −1 (dry weight basis). The mean iAs contents in polished white, brown, black, and waxy rice were 65, 109, 91, and 66 μg kg −1 , respectively. The percentages of ready-to-eat rice products, white, brown, black, and waxy rice containing iAs over the maximum level (100 μg kg −1 ) set by EU for the infant foods were 17, 4, 70, 36 and 0%, respectively. [ABSTRACT FROM AUTHOR]

Rice ( Oryza sativa L.) is the world’s third largest food crop after wheat and corn. Geographic authentication of rice has recently emerged as an important issue for enhancing human health via food safety and quality assurance. Here, we aimed to discriminate rice of six Asian countries through geographic authentication using combinations of elemental/isotopic composition analysis and chemometric techniques. Principal components analysis could distinguish samples cultivated from most countries, except for those cultivated in the Philippines and Japan. Furthermore, orthogonal projection to latent structure-discriminant analysis provided clear discrimination between rice cultivated in Korea and other countries. The major common variables responsible for differentiation in these models were δ 34 S, Mn, and Mg. Our findings contribute to understanding the variations of elemental and isotopic compositions in rice depending on geographic origins, and offer valuable insight into the control of fraudulent labeling regarding the geographic origins of rice traded among Asian countries. [ABSTRACT FROM AUTHOR]

The study presents the validation results of the method carried out for analysis of free amino acids (FAAs) in rice using l -theanine as the internal standard (IS) with o -phthalaldehyde (OPA) reagent using high-performance liquid chromatography-fluorescence detection. The detection and quantification limits of the method were in the range 2–16 μmol/kg and 3–19 μmol/kg respectively. The method had a wide working range from 25 to 600 μmol/kg for each individual amino acid, and good linearity with regression coefficients greater than 0.999. Precision measured in terms of repeatability and reproducibility, expressed as percentage relative standard deviation (% RSD) was below 9% for all the amino acids analyzed. The recoveries obtained after fortification at three concentration levels were in the range 75–105%. In comparison to l -norvaline, findings revealed that l -theanine is suitable as an IS and the validated method can be used for FAA determination in rice. [ABSTRACT FROM AUTHOR]

This study provides the first investigation of the physical traits, pasting properties and volatile compounds of Cambodian rice cultivars, including traditional, improved, and improved traditional varieties, allowing for their differentiation as high and low quality rice. Analysis of the grain quality traits illustrates interesting features of traditional varieties and correlations between traits that assist with understanding texture. Untargeted profiling of volatile compounds shows that high quality fragrant varieties not only contain 2-acetyl-1-pyrroline but also several other compounds, including aldehydes, alcohols and 2-alkylfurans that contribute to overall aroma. Moreover, low odour threshold volatile compounds, which can be derived from the oxidation of unsaturated fatty acids, were more abundant in the fragrant varieties. The percentage area of both oleic and linoleic acid were found to be significantly different among the rice varieties tested. Such findings suggest that unsaturated fatty acids in milled rice contribute to rice fragrance, and thereby to overall quality. [ABSTRACT FROM AUTHOR]

Heavy metal in rice studies has attracted a greater concern worldwide. However, there have been limited studies on marketed rice samples although it represents a vital ingestion portion for a real estimation of human health risk. This study was aimed to determine both total and bioaccessible of trace elements and heavy metals (Cd, Cr, Cu, Co, Al, Zn, As, Pb and Fe) in 22 varieties of cooked rice using an inductively coupled plasma-optical emission spectroscopy. Both total and bioaccessible of trace elements and heavy metals were digested using closed-nitric acid digestion and Rijksinstituut voor Volksgezondheid en Milieu (RIVM) in vitro digestion model, respectively. Human health risks via Health Risk Assessment (HRA) were conducted to understand exposure risks involving adults and children representing Malaysian population. Zinc was the highest while As was the lowest contents for total and in their bioavailable forms. Four clusters were identified: (1) Pb, As, Co, Cd and Cr; (2) Cu and Al; (3) Fe and (4) Zn. For HRA, there was no any risks found from single element exposure. While potential carcinogenic health risks present for both adult and children from single As exposure (Life time Cancer Risk, LCR > 1 × 10 −4 ). Total Hazard Quotient values for adult and children were 27.0 and 18.0, respectively while total LCR values for adult and children were 0.0049 and 0.0032, respectively. [ABSTRACT FROM AUTHOR]

In this study, we developed a new method to detect dinotefuran and its metabolites (UF and DN) in Oryza sativa (Rice) by HPLC–MS/MS in multiple reaction monitoring (MRM) modes. The recovery rates for dinotefuran, UF and DN were 82.3–85.8%, 83.7–89.0%, and 81.6–90.2%, respectively. The dissipation kinetics of dinotefuran in rice followed a combined first + first kinetic model, where the half-lives of dinotefuran and its metabolites were determined to be between 0.5 and 2.3 days. The dinotefuran residue in brown rice sampled at day 7, 14, and 21 after the last application was 0.4131 mg/kg with a very low risk quotient (RQ) value. We recommend that the safety interval of application for rice is 7 days. The method developed in this study is simple and rapid, with high accuracy and precision which meet the requirements for quantitative analysis of dinotefuran in rice. [ABSTRACT FROM AUTHOR]

The popcorn-like aroma compound 2-acetyl-1-pyrroline (2-AP) is a key contributor to the desirable aroma of fragrant rice and is also important in the aroma of other foods, such as pandan leaf, popcorn and Mediterranean sausage. It can be formed enzymatically in the rice grain as it grows and is also formed, as part of the Maillard reaction, when rice is heated. This review examines the formation of 2-AP in rice and other foods, particularly its formation during cooking, focusing on the importance of the Maillard reaction between reducing sugar breakdown products and 1-pyrroline derived from the amino acids proline and ornithine. The synthesis of 2-AP is discussed alongside the attempts that have been made to stabilise this relatively unstable compound. The analysis of 2-AP by instrumental techniques, particularly gas chromatography-mass spectrometry and gas chromatography-olfactometry, alongside the use of sensory studies, is also discussed. [ABSTRACT FROM AUTHOR]

The cadmium (Cd) and lead (Pb) content in both white and wholemeal flour milled from 110 leading rice cultivars was assessed. The white flour Cd content ranged from <0.0025 to 0.2530 mg/kg (geometric mean (GM) = 0.0150 mg/kg), while its Pb content ranged from <0.0250 to 0.3830 mg/kg (GM = 0.0210 mg/kg). The indica types took up higher amounts of Cd and Pb than did the japonica types. Although the heavy metal content of wholemeal flour tended to higher than that of white flour, nevertheless 84.5% (Cd) and 95.4% (Pb) of the entries were compliant with the national maximum allowable concentration of 0.2000 mg/kg of each contaminant. An analysis of the Cd content in the white flour of three indica type cultivars grown in two consecutive years at two locations indicated that Cd content may be significantly affected by the conditions prevailing in the growing season. [ABSTRACT FROM AUTHOR]

This study was performed to investigate changes in the phenolic acid and vitamin E profiles of germinated rough rice following high hydrostatic pressure treatment (HPT). Rough rice was germinated at 37 °C for two days and subjected to 0.1, 10, 30, 50, and 100 MPa pressures for 24 h. The total phenolic acid content increased from 85.37 μg/g at 0.1 MPa to 183.52 μg/g at 100 MPa. The highest gallic acid (4.29 μg/g), catechin (9.55 μg/g), p -coumaric acid (8.36 μg/g), ferulic acid (14.99 μg/g), salicylic acid (14.88 μg/g), naringin (6.18 μg/g), trans -cinnamic acid (45.23 μg/g), and kaempferol (40.95 μg/g) contents occurred in the sample treated at 100 MPa after germination. The maximum vitamin E content of about 2.56 (BG) and 4.34 mg/100 g (AG) were achieved at 30 MPa. These result suggest that a combination of HPT and germination are efficient method for enhancement of functionality in rough rice, and clarify the influence of HPT conditions on the vitamin E and phenolic acid in germination rough rice. [ABSTRACT FROM AUTHOR]

The effects of pullulan on the water distribution, microstructure and textural properties of rice starch gels during cold storage were investigated by low field-nuclear magnetic resonance (LF-NMR), scanning electron microscope (SEM), and texture profile analysis (TPA). The addition of pullulan reduced the transversal relaxation time of rice starch gels during cold storage. The microstructure of rice starch gel with 0.5% pullulan was denser and more uniform compared with that of rice starch without pullulan in each period of storage time. With regard to textural properties, 0.01% pullulan addition did not significantly change the texture of rice starch gels, while 0.5% pullulan addition appeared to reduce the hardness and retain the springiness of rice starch gels ( P ⩽ 0.05). The restriction effects of pullulan on water mobility and starch retrogradation were hypothesized to be mainly responsible for the water retention, gel structure maintenance, and modification of the textural attributes of rice starch gels. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the ability of X-ray photoelectron spectroscopy (XPS) to differentiate rice macromolecules and to calculate the surface composition of rice kernels and flours. The uncooked kernels and flours surface composition of the two selected rice varieties, Thadokkham-11 (TDK11) and Doongara (DG) demonstrated an over-expression of lipids and proteins and an under-expression of starch compared to the bulk composition. The results of the study showed that XPS was able to differentiate rice polysaccharides (mainly starch), proteins and lipids in uncooked rice kernels and flours. Nevertheless, it was unable to distinguish components in cooked rice samples possibly due to complex interactions between gelatinized starch, denatured proteins and lipids. High resolution imaging methods (Scanning Electron Microscopy and Confocal Laser Scanning Microscopy) were employed to obtain complementary information about the properties and location of starch, proteins and lipids in rice kernels and flours. [ABSTRACT FROM AUTHOR]

Black and red rices ( Oryza sativa L.) were analysed for total flavonoids and phenolics and the HPLC profile including both free and bound phenolic fractions. Moreover, antioxidant activity and in vitro digestibility was determined. Content of flavonoids and polyphenols as well as antioxidant activity was higher in free phenolic fractions. Bound flavonoids in black rices were not significant contributors to antioxidant activity. The main free phenolics in black rices were ferulic, protocatechuic and trans - p -coumaric acids, while the major free phenolics in red rices were catechin, protocatechuic and caffeic acids. The main bound phenolics in black rices were ferulic and vanillic acids and quercetin, in red rice types, they were ferulic, syringic, trans - p -coumaric acids and quercetin. Newly, the presence of m -coumaric acid in red rices was detected. Steam cooked rices showed very high levels of organic matter digestibility, whereas red rices were significantly more digestible than black rices ( p < 0.05). [ABSTRACT FROM AUTHOR]

The protective capacity of Se-containing protein hydrolysates with molecular weight below 1 kDa (SPHs-3), against Pb 2+ -induced damage in PC12 and RAW264.7 cells, was investigated in this study. The cell viability, levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), superoxide dismutase (SOD), nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) in cell were analyzed. Results showed that 100 μg/ml of SPHs-3 pretreatment could significantly increase cell viability by 24.9% and 23.0% in Pb 2+ -treated PC12 and RAW264.7 cells, respectively ( P < 0.01). The levels of ROS, NO, LDH and MDA were reduced by 32.2%, 68.2%, 79.7% and 73.7% in 100 μg/ml SPHs-3 pretreated PC12 cells, respectively ( P < 0.01). SPHs-3 pretreatment was also associated with increases of SOD activity and GSH content in cells. In conclusion, SPHs-3 could protect cells against Pb 2+ -induced cytotoxicity, suggesting that Se-enriched rice may be a feasible candidate to improve health standard of the Pb 2+ -pollution population. [ABSTRACT FROM AUTHOR]

This study investigated total arsenic and arsenic speciation in rice using ion chromatography with mass spectrometric detection (IC-ICP-MS), covering the main rice-growing regions of the Iberian Peninsula in Europe. The main arsenic species found were inorganic and dimethylarsinic acid. Samples surveyed were soil, shoots and field-collected rice grain. From this information soil to plant arsenic transfer was investigated plus the distribution of arsenic in rice across the geographical regions of Spain and Portugal. Commercial polished rice was also obtained from each region and tested for arsenic speciation, showing a positive correlation with field-obtained rice grain. Commercial polished rice had the lowest i-As content in Andalucia, Murcia and Valencia while Extremadura had the highest concentrations. About 26% of commercial rice samples exceeded the permissible concentration for infant food production as governed by the European Commission. Some cadmium data is also presented, available with ICP-MS analyses, and show low concentration in rice samples. [ABSTRACT FROM AUTHOR]

Brown rice (BR) contains bran layers and embryo, where a variety of nutritional and biofunctional components, such as dietary fibers, γ-oryzanol, vitamins, and minerals, exist. However, BR is consumed less than white rice because it has an inferior eating texture when cooked. Germination is one of the techniques used to improve the texture of the cooked BR. In addition, it induces numerous changes in the composition and chemical structure of the bioactive components. Moreover, many studies reported that the germination could induce the formation of new bioactive compounds, such as gamma-aminobutyric acid (GABA). The consumption of germinated brown rice (GBR) is increasing in many Asian countries because of its improved eating quality and potential health-promoting functions. However, there is still a lack of studies on the compositional and functional changes of the bioactive components during germination. This review contains recent research findings, especially on the bioactive components in GBR. [ABSTRACT FROM AUTHOR]

The impacts of traditional and alternative parboiling processes on the concentrations of fatty acids, tocopherol, tocotrienol, γ-oryzanol and phenolic acids in glutinous rice were investigated. Differences between the two methods were the soaking temperatures and the steaming methods. Results showed that parboiling processes significantly increased the concentrations of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), γ-oryzanol, γ-tocotrienol and total phenolic acids (TPA) in glutinous rice, while α-tocopherol, γ-tocopherol and polyunsaturated fatty acids (PUFA) decreased ( p < 0.05). Both the traditional and alternative parboiling methods increased the levels of γ-oryzanol by three or fourfold compared with the level of γ-oryzanol in raw rice. Parboiling caused both adverse and favorable effects on phenolic acids content ( p < 0.05). We found that glutinous rice, parboiled using our newly developed method, had higher levels of PUFA, total vitamin E, γ-oryzanol, hydrobenzoic acid, hydroxycinnamic acid and TPA compared to the traditional method. [ABSTRACT FROM AUTHOR]

Waxy rice starch was subjected to pulsed electric field (PEF) treatment at intensity of 30, 40 and 50 kV cm −1 . The impact of PEF treatment on the granular morphology, molecular weight, semi-crystalline structure, thermal properties, and digestibility were investigated. The micrographs suggested that electric energy could act on the granule structure of starch granule, especially at high intensity of 50 kV cm −1 . Gelatinization onset temperature, peak temperature, conclusion temperature and enthalpy value of PEF treated starches were lower than that of native starch. The 9 nm lamellar peak of PEF treated starches decreased as revealed by small angle X-ray scattering. The relative crystallinity of treated starches decreased as the increase of electric field intensity. Increased rapidly digestible starch level and decreased slowly digestible starch level was found on PEF treated starches. These results would imply that PEF treatment induced structural changes in waxy rice starch significantly affected its digestibility. [ABSTRACT FROM AUTHOR]

An analytical pressurized liquid extraction (PLE) process has been studied for the extraction of phenolic compounds from rice grains. A fractional factorial design (2 7−2 ) with a centre point was used to optimize PLE parameters such as solvent composition (EtOAc in MeOH), extraction temperature, pressure, flushing, static extraction time, solvent-purge and sample weight. Extraction temperature, solvent and static extraction time were found to have a significant effect on the response value. The optimized method was validated for selectivity, linearity, limits of detection and quantification, recovery and precision. The validated method was successfully applied for the analysis of a wide variety of rice grains. Seventeen phenolic compounds were detected in the sample and guaiacol, ellagic acid, vanillic acid and protocatechuic acid were identified as the most abundant compounds. Nonetheless, different species of rice show very varied compound diversity and levels of compounds in their grain compositions. [ABSTRACT FROM AUTHOR]

Starch extracted from broken kernels of Basmati and Irri rice varieties of Pakistani rice were subjected to modification by addition of succinic anhydride at levels of 2%, 4% and 5% based on dried weight of starch. The succinyl content of Irri rice starch increased with the concentration of succinic anhydride. Scanning electron micrographs revealed presence of dents and fusion of rice starch granules. Swelling power and water retention capacity (WRC) significantly improved after succinylation while on refrigerated storage percent decline in paste clarity of modified rice starches was stable as compared to native Basmati (BC) and Irri (IC) rice starches. Succinylation also reduced solubility, pasting temperature (PT) and gel hardness of starch gels. Improvement was observed in cold storage stability of rice starch succinates as evident from textural profile analysis. [ABSTRACT FROM AUTHOR]

The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1–39.0%, significantly higher than those of native rice starches (6.3–10.2%) and those of heat-moisture treated rice starches (18.5–23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the effects of polishing and parboiling on proximate composition, structure, phenolic compounds, antioxidant activity, cooking time and hardness of IAC-600 black rice cultivar and MPB-10 red rice lineage. Proximate analysis and light micrographs revealed higher migration of red rice proteins than black rice proteins to the endosperm as a result of parboiling. Parboiling reduced the ash content of red rice while no difference was determined in black rice. Gelatinized starch granules from both genotypes showed similar appearance. There was a decrease in relative crystallinity on both black and red rice subjected to parboiling, which was an indicative of crystallites disruption. Polishing removed more than 90% of free phenolics for both genotypes, while parboiling allowed the partial preservation of free phenolics content in polished rice. Parboiling induced an increase in the cooking time of red rice, but a decrease in the cooking time of black rice. [ABSTRACT FROM AUTHOR]

This study was aimed the extraction of total flavonoids, anthocyanins and phenolics, as well as the antioxidant activity of black rice ( Oryza sativa ) and to study the stability in relation to pH, light and copigmentation. Variations in temperature (10–50 °C), time (20–80 min), and solid–solvent ratio (1:15–1:45) were studied using a Box–Behnken design. The regression models were significant ( P < 0.001) and determination coefficients ⩾0.900. Extraction at 34.7 °C for 80 min using a solid:solvent ratio of 1:30 rendered an extract with 51.26 mg 100 g −1 of flavonoids, 116.58 mg 100 g −1 of anthocyanins, 520.17 mg 100 g −1 of phenolics and 46.50% inhibition of the DPPH radical. A decrease in the color intensity was observed when pH values were changed while anthocyanins were reversible in the process of protonation/deprotonation. The addition of glucose, phytic and gallic acids in the optimized extract exposed to light displayed an intermolecular copigmentation. The main anthocyanin identified in black rice was cyanidin-3-glucoside. [ABSTRACT FROM AUTHOR]

39 aromatic indica rice ( Oryza sativa L.) cultivars were characterized for Iron, Zinc, Calcium, Magnesium, Copper and β-carotene contents. The β-carotene contents were ranging from 1.23 to 9.9 μg/g in brown and 0.08 to 1.99 μg/g in milled rice. Among the mineral contents, Magnesium was found ranging from 855 μg/g (Gham) to maximum of 1636 μg/g (Badshahbhog) followed by Iron in 32 μg/g (Jirga) to 218 μg/g (Kalsal), Copper content from 2 μg/g (Girga) to 1004 μg/g (Gham), Zinc content from 25 (Gham) to 165 μg/g (Ambemohar-157) and Calcium ranged from 14 μg/g (Ambemohar pandhara) to 67 μg/g (Kate chinoor). The study showed that the germplasm assessed is a good source of micronutrients and can be further exploited in breeding programme. [ABSTRACT FROM AUTHOR]

With the escalating persuasion of economic and nutritional importance of rice grain protein and nutritional components of rice bran (RB), NIRS can be an effective tool for high throughput screening in rice breeding programme. Optimization of NIRS is prerequisite for accurate prediction of grain quality parameters. In the present study, 173 brown rice (BR) and 86 RB samples with a wide range of values were used to compare the calibration models generated by different chemometrics for grain protein (GPC) and amylose content (AC) of BR and proximate compositions (protein, crude oil, moisture, ash and fiber content) of RB. Various modified partial least square (mPLSs) models corresponding with the best mathematical treatments were identified for all components. Another set of 29 genotypes derived from the breeding programme were employed for the external validation of these calibration models. High accuracy of all these calibration and prediction models was ensured through pair t -test and correlation regression analysis between reference and predicted values. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of puffing process on the physical, antioxidant properties and mineral composition of brown rice. Bulk density significantly varied ( P < 0.05) among the puffing stages and was lowest in expanded rice. From Hunter colour analysis, the lowest L ∗ value and highest a ∗ and b ∗ values were observed for parboiled rice ( P < 0.05). A-type of diffraction pattern, observed in raw rice was altered by puffing process and led to the formation of B- and V-type patterns. Raman spectrum showed the intense peaks in raw rice and the intensity of those peaks was decreased during the puffing process. Scanning electron microscopy revealed a highly porous structure of expanded rice kernel. Significant decrease in the antioxidant properties was observed upon puffing process as compared to raw rice samples. Hence the present study demonstrates that the puffing process leads to the significant changes in the properties of brown rice. [ABSTRACT FROM AUTHOR]

The determination of inorganic arsenic species in water, beverages and foods become crucial in recent years, because arsenic species are considered carcinogenic and found at high concentrations in the samples. This communication describes a new cloud-point extraction (CPE) method for the determination of low quantity of arsenic species in the samples, purchased from the local market by UV–Visible Spectrophotometer (UV–Vis). The method is based on selective ternary complex of As(V) with acridine orange (AOH + ) being a versatile fluorescence cationic dye in presence of tartaric acid and polyethylene glycol tert -octylphenyl ether (Triton X-114) at pH 5.0. Under the optimized conditions, a preconcentration factor of 65 and detection limit (3S blank / m ) of 1.14 μg L −1 was obtained from the calibration curve constructed in the range of 4–450 μg L −1 with a correlation coefficient of 0.9932 for As(V). The method is validated by the analysis of certified reference materials (CRMs). [ABSTRACT FROM AUTHOR]

A highly sensitive and selective procedure for the determination of arsenate and total arsenic in food by electrothermal atomic absorption spectrometry after cloud point extraction (ETAAS/CPE) was developed. The procedure is based on the formation of a complex of As(V) ions with molybdate in the presence of 50.0 mmol L −1 sulfuric acid. The complex was extracted into the surfactant-rich phase of 0.06% (w/v) Triton X-114. The variables affecting the complex formation, extraction and phase separation were optimized using factorial designs. Under the optimal conditions, the calibration graph was linear in the range of 0.05–10.0 μg L −1 . The detection and quantification limits were 10 and 33 ng L −1 , respectively and the corresponding value for the relative standard deviation for 10 replicates was below 5%. Recovery values of between 90.8% and 113.1% were obtained for spiked samples. The accuracy of the method was evaluated by comparison with the results obtained for the analysis of a rice flour sample (certified material IRMM-804) and no significant difference at the 95% confidence level was observed. The method was successfully applied to the determination of As(V) and total arsenic in rice samples. [ABSTRACT FROM AUTHOR]

A new microwave-assisted extraction (MAE) method has been investigated for the extraction of phenolic compounds from rice grains. The experimental conditions studied included temperature (125–175 °C), microwave power (500–1000 W), time (5–15 min), solvent (10–90% EtOAc in MeOH) and solvent-to-sample ratio (10:1 to 20:1). The extraction variables were optimised by the response surface methodology. Extraction temperature and solvent were found to have a highly significant effect on the response value ( p < 0.0005) and the extraction time also had a significant effect ( p < 0.05). The optimised MAE conditions were as follows: extraction temperature 185 °C, microwave power 1000 W, extraction time 20 min, solvent 100% MeOH, and solvent-to-sample ratio 10:1. The developed method had a high precision (in terms of CV: 5.3% for repeatability and 5.5% for intermediate precision). Finally, the new method was applied to real samples in order to investigate the presence of phenolic compounds in a wide variety of rice grains. [ABSTRACT FROM AUTHOR]

Highlights: [•] We tested the effect of drought on chemical composition of tolerant transgenic rice. [•] In response to a water deficit, the levels of several nutrients were altered. [•] Drought stress increased copper and potassium levels in transgenic rice. [ABSTRACT FROM AUTHOR]

Highlights: [•] The feasibility study of using Hg-spiked rice as a QCM was performed. [•] The rice powder was coated with halogen compounds (CCl4, CH2CHCH2Br, and CH3I). [•] The coating materials were used to produce rice RMs with desired Hg concentrations. [•] The in-lab prepared Hg-spiked rice exhibited sufficient homogeneity and stability. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rice samples from different growing regions in China had a significant difference in Pb, Cd and As content. [•] In fresh edible mushroom, Pb and Hg contents in 2.6% samples were above MAC. [•] More than 95% rice and edible mushroom samples in our test had high edible safety. [ABSTRACT FROM AUTHOR]

Highlights: [•] Phytochemicals in Japanese black–purple rice investigated. [•] Contain high levels of anthocyanins. [•] Substantial quantities of flavonols and flavones also occur. [•] High levels of γ-Oryzanols present. [•] Trace levels of carotenoids detected. [Copyright &y& Elsevier]

Abstract: Phospholipids (PLs) are a major class of lipid in rice grain. Although PLs are only a minor nutrient compared to starch and protein, they may have both nutritional and functional significance. We have systemically reviewed the literature on the class, distribution and variation of PLs in rice, their relation to rice end-use quality and human health, as well as available methods for analytical profiling. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and their lyso forms are the major PLs in rice. The deterioration of PC in rice bran during storage was considered as a trigger for the degradation of rice lipids with associated rancid flavour in paddy and brown rice. The lyso forms in rice endosperm represent the major starch lipid, and may form inclusion complexes with amylose, affecting the physicochemical properties and digestibility of starch, and hence its cooking and eating quality. Dietary PLs have a positive impact on several human diseases and reduce the side-effects of some drugs. As rice has long been consumed as a staple food in many Asian countries, rice PLs may have significant health benefits for those populations. Rice PLs may be influenced both by genetic (G) and environmental (E) factors, and resolving G×E interactions may allow future exploitation of PL composition and content, thus boosting rice eating quality and health benefits for consumers. We have identified and summarised the different methods used for rice PL analysis, and discussed the consequences of variation in reported PL values due to inconsistencies between methods. This review enhances the understanding of the nature and importance of PLs in rice and outlines potential approaches for manipulating PLs to improve the quality of rice grain and other cereals. [Copyright &y& Elsevier]