Rice Samples Research Articles

Simultaneously Selective Separation of Zearalenone and Four Aflatoxins From Rice Samples Using Co-Pseudo-Template Imprinted Polymers With MIL-101(Cr)-NH2 as Core.

A novel approach for the simultaneous separation of zearalenone (ZEN) and four types of aflatoxins (AFB1, AFB2, AFG1 and AFG2) from rice samples was presented. This approach utilized modified MIL-101(Cr)-NH2 as core, with molecularly imprinted polymers (MIPs) serving as the shell. The MIL-101(Cr)-NH2 was prepared via ring-opening reaction, while the imprinted polymers were synthesized using warfarin and 4-methylumbelliferyl acetate as co-pseudo template, ethylene glycol dimethacrylate as the cross-linker and azobisisobutyronitrile as initiator. The resulting co-pseudo-template-MIPs (CPT-MIPs) were thoroughly characterized and evaluated. Adsorption studies demonstrate that the adsorption process of CPT-MIPs follows a chemical monolayer adsorption mechanism, with imprinted factors ranging from 1.24 to 1.52 and selective factors ranging from 1.29 to 1.52. Self-made columns were prepared, and the method for separation was developed and validated. The limit of detections ranged from 0.12 to 2.09μg/kg, and the limit of qualifications ranged from 1.2 to 6.25μg/kg. To assess the reliability of the method, ZEN and AFs were spiked at three different levels, and the recoveries ranged from 79.53 to 94.58%, with relative standard deviations of 2.90-5.78%.

Assessment of potentially toxic metals in selected local and foreign rice brands from Southwestern Nigeria: Implications for human health

This study evaluated the presence of potentially toxic metals (PTMs) in different local and foreign rice brands from southwestern Nigeria. Eight brands were purchased in four states: Oyo, Osun, Ogun, and Lagos. A total of sixty-four rice samples were analyzed for PTMs (Cd, Pb, Cr, Ni, Cu, Fe, Mn, and Zn) using an atomic absorption spectrophotometer. The data collected were analyzed for descriptive and inferential statistics. Health risk assessments were conducted to evaluate non-carcinogenic risks, including hazard quotient (HQ), hazard index (HI), and cancer risk (CR). The results revealed high concentrations of Pb (7.13±5.40 mg/kg) and Cd (8.71±3.81 mg/kg) in the local brand and a high Cr (5.91±3.71 mg/kg) in the foreign brand, which exceeded the WHO permissible limits of 0.2, 0.3, and 1.0 mg/kg, respectively. The health risk assessment revealed that the HQ values exceeded the permissible limit of 1.0 for Pb, Cd, and Cr in most of the rice brands, indicating adverse health effects. The CR data revealed health concerns for Cd, Cr, and Ni, with values exceeding the limit of 1.0 × 10−4. This suggests a potential risk of cancer development associated with consuming the locally produced and imported rice in the states under study.

Analysis of arsenic in rice and domestic water supply in Baguio City, Philippines

Numerous studies have found that rice and water, as components of the human diet, are potential pathways of arsenic exposure in humans. Due to the negative health effects linked with arsenic exposure, the quality of drinking water and rice samples must be continually monitored. This research was carried out in Baguio City, a small urban center in the Philippines. Following microwave digestion, arsenic in rice and water samples were determined using Atomic Absorption Spectrometry. The results showed that the National Food Authority (NFA) rice samples had arsenic content below the detection limit, indicating that this commercially available rice does not pose any health risk to Filipino consumers in terms of arsenic exposure. The arsenic value in other rice samples ranged from 8 μg/L to 27 μg/L, with the lowest and highest values found in organic brown rice and white rice varieties, respectively. Despite detectable arsenic in all 20 rice samples, all values were less than the maximum contaminant level (MCL) of 150 μg/L. Despite higher arsenic content in mixed rice than in white and organic colored rice, the mean differences are not significant, as proven by the Kruskal Wallis Test. All drinking water samples bought from water refilling stations had no detectable arsenic, while eight of the 18 (44%) of the spring water samples showed detectable amounts but are far below MCL of arsenic in drinking water. The findings suggest that the amount of arsenic in rice and spring water samples are too low to pose health risks over a short period of time.

Rational design and application of broad-spectrum antibodies for Bt Cry toxins determination

Using the amino acid sequences and analysis of selected known structures of Bt Cry toxins, Cry1Ab, Cry1Ac, Cry1Ah, Cry1B, Cry1C and Cry1F we specifically designed immunogens. After antibodies selection, broad-spectrum polyclonal antibodies (pAbs) and monoclonal antibody (namely 1A0-mAb) were obtained from rabbit and mouse, respectively. The produced pAbs displayed broad spectrum activity by recognizing Cry1 toxin, Cry2Aa, Cry2Ab and Cry3Aa with half maximal inhibitory concentration (IC50) values of 0.12–9.86 μg/mL. Similarly, 1A0-mAb showed broad spectrum activity, recognizing all of the above Cry protein (IC50 values of 4.66–20.46 μg/mL) with the exception of Cry2Aa. Using optimizations studies, 1A10-mAb was used as a capture antibody and pAbs as detection antibody. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISAs) were established for Cry1 toxin, Cry2Ab and Cry3Aa with the limit of detection (LOD) values of 2.36–36.37 ng/mL, respectively. The present DAS-ELISAs had good accuracy and precisions for the determination of Cry toxin spiked tap water, corn, rice, soybeans and soil samples. In conclusion, the present study has successfully obtained broad-spectrum pAbs and mAb. Furthermore, the generated pAbs- and mAb-based DAS-ELISAs protocol can potentially be used for the broad-spectrum monitoring of eight common subtypes of Bt Cry toxins residues in food and environmental samples.

The effect of gamma ray re-irradiation on genetic variations in black rice based on RAPD and Bph gene resistance location based on SSR markers

Abstract The black rice variety Cempo Ireng M8 generation already has morphologically uniform characteristics and good productivity values. However, the black rice M8 generation is still susceptible to planthopper pests. Therefore, a re-irradiation process was carried out on M8 using 200 Gy gamma rays to obtain a black rice variety resistant to planthopper pests. This re-radiation treatment has produced the M2 generation. To determine the genetic variations between M8 black rice plants and the M2 generation that are formed, this research conducted molecular methods using six RAPD markers and three SSR markers to determine genes in the sample related to the Bph resistance gene. The sequenced SSR amplicons were analyzed using BLAST in NCBI. The results of the RAPD marker showed genetic variation in the seven black rice samples with an average polymorphism percentage of 92.85% and the Polymorphic Information Content (PIC) value for the six primers was between 0.25-0.5, which means the RAPD primers is informative. The analysis and sequence results of the RM5953 primer show that the primer is located in the Bph resistance gene (chromosome 4) and produces an amplicon at a band size of 129 bp.

Aflatoxin exploration in basmati brown rice collected from various locations of Lahore, Pakistan

Aflatoxins are produced by various fungal species, the two primaries being Aspergillus flavus and Aspergillus parasiticus. Aflatoxins contaminate various food products, resulting in them being toxic and unsafe for consumption, hence, being classified as potent carcinogens. In this paper, samples of brown basmati rice were analyzed for contamination with aflatoxins using the ELISA method. 50 brown rice samples were collected from various shops in Lahore, Pakistan, in the year 2019-2020. During summer, 25 of the samples were collected from April-September whereas the rest 25 were collected in winter from October-March. The rice samples were in a poor condition because of high levels of aflatoxin contaminations. The percentage of aflatoxins contamination for summer and winter was 88% and 80% respectively. Further, 60% of summer collected samples and 44% of winter collected samples exceeded the permissible level allowed by European Union (10μg/kg for total aflatoxins). The samples with the highest aflatoxin for summer contained 49.60±0.45μg/kg whereas for winter the concentration was 25.07±0.04 μg/kg. With regard to their toxic nature and harm to human health, these calculated levels were frightening. These show a dire need for the implementation of practices to monitor the quality of these rice by all the rice producers and storage holders in Pakistan.

Investigatory study on the qualities of locally grown Rice brands sold in main markets of Abeokuta, South-Western Nigeria

Qualities of some selected rice varieties sold in the main markets of Abeokuta, the capital of Ogun State where rice is mostly grown and consumed in the south-western part of Nigeria was investigated. Rice (Aroso, Mokwa, Royal niger, Orlam and Ofada rice) were evaluated for their physical, chemical properties and sensory qualities using established laboratory procedures. The average width of the rice ranged from “0.261 to 0.268 mm”, “0.260 to 0.265 mm, “0.260 to 0.262 mm”, “0.269 to 0.270 mm”, and 0.271 to 0.275 mm” respectively. The rice average lengths ranged between “0.346 to 0.350 mm”, “0.365 to 0.368 mm”, “0.356 to 0.359 mm”, “0.357 to 0.357 mm” and “0.365 to 0.379 mm” respectively. The physical appearance of the rice investigated ranged from good to very good except for mokwa and orlam rice which shows fair colours. Chemical properties of the rice samples ranged from 10.21 to 11.97%, 0.83 to 2.62, 1.89 to 2.16%, 0.24 to 0.37%, 5.50 to 7.56%, 77.89 to 79.60%, 59.90 to 65.17%, 12.15 to 14.61% and 85.39 to 87.85% for moisture, total ash, fat, crude fibre, crude protein, carbohydrate, starch, amylose and amylopectin contents respectively. The cooking properties ranged from 2 to 7.5, 230 to 250% and 5.49 to 5.64 in length and 0.689 to 1.337mm for volume expansion ratio, water uptake and elongation ratio respectively. This study revealed that Aroso and Orlam rice were of excellent in physical, chemical, sensory qualities and are both recommended for consumption. This research finding serves as a basis of choice for consumers and it also reveals the areas for improvement in terms of qualities of the local rice investigated.

Exploring the elemental variations in commercial non-glutinous brown and white rice from Malaysia by chemometrics

The concentrations of Na, Mg, K, Ca, Mn, Fe, Cu, and Zn in a selection of commercial non-glutinous rice sampled from Malaysia were determined using microwave assisted digestion with inductively coupled plasma-mass spectrometry and the data obtained were evaluated using chemometric techniques. Both principal component analysis and hierarchical cluster analysis revealed two distinct clusters where the brown rice is associated with higher elemental content compared to the white rice; and Mg level was identified as a key discriminatory factor according to linear discriminant analysis outcomes. The concentrations of macroelements used to exhibit a consistent sequence: K > Mg > Ca > Na; whereas no regular trend was observed on the microelements. The results suggested that the elemental variations in the rice samples were largely attributed to the grain treatment processes while the impacts of the other underlying factors are more apparent on microelemental concentrations. From the nutritional assessment, brown rice appeared to be a noteworthy dietary source of Mg, Mn, and Zn, however, the contributions of Na and Ca to daily needs are negligible.

Co-contamination and interactions of multiple mycotoxins and heavy metals in rice, maize, soybeans, and wheat flour marketed in Shanghai City

Mycotoxins and heavy metals extensively contaminate grains and grain products, posing severe health risks. This work implements validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) methods to quantify the concentration of 12 mycotoxins and five heavy metals in rice, maize, soybeans, and wheat flour samples marketed in Shanghai. The mixed contamination characteristics were analyzed using correlation cluster analysis and co-contamination index, and the probabilities of all cross combinations of contaminations were analyzed using a self-designed JAVA language program. The results showed that grains and grain products were frequently contaminated with both mycotoxins and heavy metals, mostly with deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON), ochratoxin A (OTA), aflatoxins, fumonisin B1 (FB1), fumonisin B2 (FB2), fumonisin B3 (FB3), arsenic (As), chromium (Cr) and cadmium (Cd). All the samples (100 %) were contaminated with two or more contaminants, and 77.3 % of the samples were co-contaminated with more than four contaminants. In cereals and cereal products, the following combinations were closely associated: (FB3 +3-ADON), (FB1 +As), (FB1 +FB2), (DON+FB1), (DON+Cd), (As+Cd), (DON+Cd+As), (FB1 +FB2 +As), and (DON+3-ADON+15-ADON). The results indicated that mycotoxins and heavy metals frequently co-occurred in Shanghai grains and grain products, and they provided primary data for safety assessments, early warnings, and regulatory measures on these contaminants to protect public health.

Computerized analysis of haptens for the ultrasensitive and specific detection of Pyriftalid

Pyriftalid (Pyr) is one of the most commonly used herbicides and due to its widespread and improper use, it has led to serious pollution of groundwater, soil and other ecosystems, threatening human health. A rapid method to detect Pyr was urgently needed. A high specific monoclonal antibody (mAb) against Pyr with IC50 values of 4.7 ng/mL was obtained by mAb screening technique and method with enhanced matrix effect. The study firstly proposed colloidal gold immunochromatographic test strips (CGIA) for Pyr, which enables rapid qualitative and quantitative determination of a large number of samples anytime and anywhere, so as to effectively monitor Pyr in environment and grain samples. Based on the properties of the desired Pyr antibody, the hapten Pyr-hapten-4 with high structural similarity to Pyr molecule, similar electrostatic potential distribution, and the ability to expose Pyr functional groups was screened out from five different Pyr haptens, which was consistent with mouse antiserum test. The CGIA quickly analyze the Pyr content in positive samples such as water samples, soil samples, paddy samples, brown rice samples within 10 min, the LOD for Pyr by CGIA as low as 1.84 ng/g, the v LOD value as low as 6 ng/g, and the extinction value as low as 25 ng/g. The content of positive samples detected by CGIA was consistent with the quantitative results of LC-MS/MS, the relative accuracy was within the range of 97–103 %. The recovery rate range for Pyr by CGIA was 92.0–99.7 %, and the coefficient of variation was between 1.30–8.56 %. It indicated Pyr-targeted CGIA test strip was an efficient and fast detection method to detect real environment and food samples.

Old Foe, New Host: Epidemiology, Genetic Diversity, and Pathogenic Characterization of Maize Streak Virus in Rice Fields from Burkina Faso

Rice is of critical significance regarding food security worldwide, including in Africa. Only two viruses impacting rice production in Africa have been deeply investigated for decades: the rice yellow mottle virus ( Solemoviridae) and the rice stripe necrosis virus ( Benyviridae). Using viral metagenomics, we aimed at broadening knowledge on interacting communities associated with plants in rice landscapes and exploring the diversity and epidemiological status of viruses circulating in rice fields from Burkina Faso. We performed an epidemiological survey in this country between 2016 and 2019 involving 57 small farmers’ rice fields under two production systems: rainfed lowlands and irrigated areas. More than 2,700 rice samples were collected without regard to disease symptoms following a regular scheme. Wild and cultivated Poaceae (maize and sugarcane) growing in nearby rice fields were also collected. Unexpectedly, metagenomics detected maize streak virus (MSV) ( Geminiviridae) in analyzed rice samples. Further molecular analyses using rolling circle amplification-polymerase chain reaction showed that MSV was widely distributed and highly prevalent in both rainfed lowlands and irrigated rice areas. MSV-A and MSV-G strains were identified. MSV-G, exclusively identified thus far in wild grasses, was the most prevalent strain, whereas MSV-A, known to cause severe symptoms in maize, was sporadically identified. Using infectious clones in experimental conditions, we confirmed the pathogenicity of both MSV strains in rice. Thus, in addition to contributing to the epidemiological surveillance of rice production in Africa, our results illuminate new epidemiological and pathogenic aspects of one of the most studied plant viruses with significant economic consequences in Africa. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Geographical origin identification of Khao Dawk Mali 105 rice using combination of FT-NIR spectroscopy and machine learning algorithms

The mislabelled Khao Dawk Mali 105 rice coming from other geographical region outside the Thung Kula Rong Hai region is extremely profitable and difficult to detect; to prevent retail fraud (that adversely affects both the food industry and consumers), it is vital to identify geographical origin. Near infrared spectroscopy can be used to detect the specific content of organic moieties in agricultural and food products. The present study implemented the combinatorial method of FT-NIR spectroscopy with chemometrics to identify geographical origin of Khao Dawk Mali 105 rice. Rice samples were collected from 2 different region including the north and northeast of Thailand. NIR spectra data were collected in range of 12,500 – 4,000 cm−1 (800–2,500 nm). Five machine learning algorithms including linear discriminant analysis (LDA), partial least squares discriminant analysis (PLS-DA), C-support vector classification (C-SVC), backpropagation neural networks (BPNN), hybrid principal component analysis-neural network (PC-NN) and K-nearest neighbors (KNN) were employed to classify NIR data of rice samples with full wavelength and selected wavelength by Extremely Randomized Trees (Extra trees) algorithm. Based on the findings, geographical origin of rice could be specified quickly, cheaply, and reliably using combination of NIRS and machine learning. All models creating by full wavelength and selected wavelength exhibited accuracy between 65 and 100 % for identifying geographical region of rice. It was proven that NIR spectroscopy may be used for the quick and non-destructive identification of geographical origin of Khao Dawk Mali 105 rice.

Senna auriculata extract-assisted biogenic synthesis of yellow emissive gold nanoclusters for quantitative detection of glyphosate in food and environmental samples

The green chemistry approach was unitized for the development of fluorescent nanomaterial. The objective of this study is to develop plant-based fluorescence nanomaterials via environment-friendly and biocompatible approach. Here, water-soluble yellow emissive gold nanoclusters were synthesized by using extract of Senna auriculata leaves and 1.25 mM of HAuCl4·xH2O via microwave-assisted method. Senna auriculata-AuNCs (S. auriculata-AuNCs) exhibit excellent solubility, good quantum yield (QY), stability, and biocompatibility. The ultra-small (<5 nm) size of S. auriculata-AuNCs displayed yellow emission and were characterized by using fluorescence, UV–visible, FT-IR, HR-TEM, zeta potential, DLS, XPS, and XRD techniques. S. auriculata-AuNCs display an intense emission of 620 nm when excited at 500 nm. The as-synthesized S. auriculata-AuNCs act as an effective sensor for sensing glyphosate pesticide via the “turn-off” mechanism. Moreover, S. auriculata-AuNCs showed a good performance in detecting glyphosate with a wider linear range from 0.05 to 100 µM, offering the detection limit of 32.0 nM for glyphosate. Additionally, S. auriculata-AuNCs are also able to visualize Saccharomyces cerevisiae cells, and successfully applied in assaying glyphosate pesticide in apple, rice, river, and canal water samples.

Development of folding-based and signal-amplified fluorescence aptasensors using G-quadruplex quinclorac aptamer variants engineered via exonuclease digestion and circular dichroism spectroscopy

The lack of inherent structure-switching functionality and inadequate affinity in aptamers hinders the construction and application of aptasensors. While exonuclease digestion-based strategies have been employed to engineer small-molecule aptamers with the structure-switching functionality and construct dual-exonuclease (exonuclease I and exonuclease III) digestion-based aptasensors, such studies targeting G-quadruplex (G4) aptamers remain scarce. This study focused on the exonuclease digestion and circular dichroism spectroscopy analysis of a G4 quinclorac (QNC) aptamer, Qapt-51, intending to design a functionalized QNC aptamer and a universal signal amplification strategy for constructing folding-based and sensitive dual-exonuclease digestion-based aptasensors, respectively. The exonuclease digestion results demonstrated that QNC-binding Qapt-51 inhibited the dual-exonuclease digestion. Combining the results from the circular dichroism spectroscopy, we further proposed a digestion mechanism for Qapt-51 involving a G4 conformational switch. Inspired by this mechanism, a functionalized Qapt-51 variant (Qapt-45A) was rationally designed to construct a simple and rapid folding-based fluorescence aptasensor. Additionally, we developed an exonuclease III- and phosphorodiamidate morpholino oligomer-assisted fluorescence signal amplification strategy, which can work in the dual-exonuclease digestion system. Leveraging this strategy integrated with the dual-exonuclease digestion of another Qapt-51 variant (AQ), a homogeneous signal-amplified fluorescence aptasensor was constructed to sensitively detect QNC without requiring the functionalized aptamers. These two aptasensors achieved detection limits of 560 ng/mL and 8.5 ng/mL for QNC. They successfully detected QNC in rice and river water samples with recoveries of 108.6%-87.5%. We hope that the successful development of these two aptasensors can provide valuable insights and references for the broader construction of G4 aptamer-based sensing systems.

Evaluation of pesticide residues in rice marketed in Cape Verde by QuEChERS-LC/GC-MS analysis

In this work, a multiresidue pesticide analysis using both gas chromatography and ultra-high performance liquid chromatography coupled to mass spectrometry systems has been conducted to determine 151 pesticides in rice samples consumed by the population of Cape Verde. The extraction and clean-up procedures were carried out by the QuEChERS method. The validation of both methodologies achieved determination coefficients higher than 0.9902 in matrix-matched calibration, relative recovery values in the range 58–120% with relative standard deviation lower than 20%, and limits of quantification of the method in the range 0.008–0.017 mg/kg, which agreed with the legal limits established by both EU regulations and the Codex Alimentarius guidelines. Among the total of 98 rice samples analysed, 91 samples were contaminated by pesticides at concentrations up to 18.3 mg/kg, with pirimiphos-methyl, propiconazole, tebuconazole, and imidacloprid being the most frequently detected. Following EU regulations, 14 non-compliances were found in 13 samples, whereas only one non-compliance was identified according to the Codex. Besides, a risk assessment based on the dietary exposure was performed for the pesticides found in the analysed rice samples. The results showed the need to carry out stricter controls to ensure the security of food agricultural products to protect consumers’ health.

Relationship between the physicochemical properties and amylose content of rice starch in rice varieties with the same genetic background

This study analyzed six mutant rice samples from uniform genetic and planting backgrounds with amylose contents ranging from 4.21% to 17.52%. The physicochemical, structural and functional properties of the extracted starches were investigated and their relationships were analyzed. No significant changes were observed in the morphology, granule size, amylopectin chain-length distribution, and crystalline type of rice starches. The average hydrodynamic radius (Rh), relative crystallinity (RC), the ratio of 1045 cm−1/1022 cm−1 (R1045/1022), and lamellar peak intensity (Imax) were significantly correlated with amylose content, impacting the digestion properties. A higher degree of order in starch structure was found to impede its digestion progress by affecting its physicochemical characteristics. The decreased onset temperature and increased gelatinization temperature range indicated increased crystalline structure instability, decreasing peak time and pasting temperature. Furthermore, there were notable reductions in starch digestion rate (k) and rapidly digestible starch content (RDS) as amylose content increased, despite no significant change in the final digestion percentage. The k exhibited a positive correlation with Rh, while there was a positive association between RC, R1045/1022, and Imax with RDS. These findings can provide valuable guidance for rice breeders in developing rice varieties with specific functional attributes.

Evaluation of carcinogenic risk of heavy metals due to consumption of rice in Southwestern Iran

Pollution by heavy metals is a serious global problem due to its toxicity, abiotic characteristics, abundant sources, and cumulative behavior. On the other hand, considering the importance of rice consumption as an important part of nutrition in Lordegan and Ahvaz cities, this study was conducted to evaluate the carcinogenic risk of heavy metals lead, cadmium, zinc, nickel and in local Champa rice cultivated in these two cities. 16 Champa rice samples were collected from the fields of Lordegan and Ahvaz cities. The elements were read in three replicates by Varian 710-ES atomic emission device. The results showed that the concentration of cadmium and nickel in the cultivated rice in the two studied cities was within the range of the national standard of Iran and the Codex standard. Carcinogenic risk values for lead, cadmium and nickel in Champa Lordegan and Ahvaz rice were within the safe range. Also, the non-carcinogenic risk for these heavy metals in the two studied areas was less than 1 and was in the safe range. Rice pollution in Champa in Ahvaz can be due to the industrial nature of this city, and in Lordegan, it is due to pollution through pesticides, chemical fertilizers, and transportation. Long-term consumption of contaminated rice may endanger the health of residents of these areas. It is recommended to carry out regular and up-to-date monitoring strategies in these two cities to prevent the entry of these toxic heavy metals into the human food chain. Also, more studies are needed to evaluate the complete scenario and make definitive decisions.

One-Pot Preparation of Mixed-Mode Reversed-Phase Anion-Exchange Silica Sorbent and its Application in the Detection of Cyclopiazonic Acid in Feeds and Agricultural Products.

A novel co-bonded octyl and pyridine silica (OPS) sorbent was prepared and applied for the solid phase extraction (SPE) of cyclopiazonic acid (CPA, a type of mycotoxin) in feed and agricultural products for the first time. A simple mixed-ligand one-pot reaction strategy was employed for OPS sorbent preparation. Nitrogen adsorption-desorption measurements, elemental analysis (EI), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) analysis demonstrated the successful immobilization of octyl and quaternary ammonium groups onto the surface of silica gel. The large specific surface area, high-density functional groups, and mixed-mode anion-exchange characteristics of these silica particles made them the ideal material for the efficient extraction of CPA. Additionally, the OPS sorbents displayed excellent batch-to-batch reproducibility, satisfactory reusability, and low cost. The SPE parameters were optimized to explore the ionic and hydrophobic interactions between CPA and the functional groups, and the ultra-high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-MS/MS) parameters were optimized to obtain a desirable extraction efficiency and high sensitivity to CPA. Meanwhile, the OPS sorbent presented a satisfactory extraction selectivity and low matrix effect. Under the optimized conditions, our developed CPA detection method was used to determine CPA level in rice, wheat flour, corn flour, peanut, and feed samples, exhibiting a lower detection limit, better linearity, higher sensitivity, and satisfactory extraction recovery rate than previously reported methods. Therefore, our method can be preferentially used as a method for the detection of CPA in agricultural products and feeds.

Effects of atmospheric deposition on heavy metal contamination in paddy field systems under different functional areas in ChangZhuTan, Hunan Province, China

In recent decades, the problem of heavy metal contamination in rice paddies has attracted widespread attention. However, most studies on heavy metal contamination in paddy fields are biased towards soil and/or rice plants, without taking atmospheric deposition into account. In this study, atmospheric deposition, paddy soil, and rice samples were collected from three functional areas (area proximity to factories, along the roadside, and suburban) in ChangZhuTan, Hunan Province. The pollution characterization, translocation, and health risk of heavy metals were reassessed. The findings revealed that Cd and As contamination in the study area's soils was more severe, with point exceedance rates reaching 70 % and 35.9 %, respectively. The highest concentrations of As, Ni, Cd, and Pb in atmospheric deposition were found along the roadside, with 1.42 μg/m2/day, 3.21 μg/m2/day, 0.34 μg/m2/day, and 8.28 μg/m2/day, respectively. In area proximity to factories, As and Ni in atmospheric deposition showed to be lowest, whereas Cd and Pb concentrations showed lowest in suburban areas. Furthermore, the accumulation of Cd and Pb in rice grains in regions proximity to factories was significantly higher than in other regions. The human health risk assessment indicated the health risk caused by rice intake in areas proximity to factories was the highest and requires attention, which was mainly due to Cd accumulation, with HQ value reached 3.19. Correlation tests indicate that atmospheric deposition has a positive effect on heavy metal enrichment in rice grains. Further Random Forest analysis revealed that the transport of heavy metals from atmospheric deposition to leaves and shells were important influencing factors for As, Cd, Ni and Mg accumulation in rice grain. Therefore, more attention should be paid to the effects of atmospheric deposition on the accumulation of heavy metals in paddy fields in order to maintain the production safety of crops.

Variation in amylose content in three rice variants predominantly influences the properties of sushi rice

Sushi rice is a ready-to-eat traditional Japanese dish seasoned with vinegar, sugar and salt that has gained popularity worldwide. There are many rice cultivars grown in the world which vary in their cooking, sensory, and processing quality. The aim of this study was to analyse chemical, physical, and functional properties of three rice varieties (Vietnamese, Italian, and Australian) to determine their suitability for sushi rice production. Rice was cooked using industry norms and vinegar was then added; samples with no vinegar were prepared for comparison. The rice was stored during 5 days at 4 °C after cooking for texture profile analysis and samples were taken on day 1 and day 5. Flour composition as well as amylose content, gelatinisation properties using differential scanning calorimeter, pasting properties using Rapid Visco Analyser, water absorption capacity (WAC), oil absorption capacity (OAC) and swelling power of extracted starch were determined. Results showed that the amylose content (16.51 to 21.37%) had a large impact on the functional and quality characteristics of the rice variants including texture, pasting, gelatinisation and WAC properties. Australian starch showed the highest amylose content, setback viscosity, final viscosity, pasting temperature and lowest gelatinisation temperature. The lower amylose content and gelatinisation temperature contributed to a softer texture in the Vietnamese rice samples over life. The added vinegar aided in keeping the texture soft during the shelf-life of the rice. Since sushi rice is usually prepared with vinegar, Italian and Vietnamese rice are better candidates for sushi rice based on their lower hardness after 5 days of storage when compared to the Australian variety.