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Preparation of high-purity α-Si3N4 nano-powder by precursor-carbothermal reduction and nitridation
摘要： This work investigated the role of natural organic matter (NOM) in the environmental processes of silver nanoparticles (AgNP) and the uptake and accumulation of AgNP in wheat. Different NOMs (Suwannee River humic acids [SRHA], fulvic acid [FA]) and Ag elements (Ag(0) and Ag+) were incubated in a hydroponic media for 15 days. The results showed that the NOM (10 mg C L-1) altered the dissolution, stabilization, uptake and accumulation of AgNP. The dissolution of AgNP declined in the presence of NOM. Compared with FA, the dissolved Ag+ decreased much more from 0.30 mg L-1 to 0.10 mg L-1 in the presence of SRHA. The fluorescence quenching results indicated that SRHA exhibited stronger binding to Ag+ than that of FA, and the quenching constants Ksv were 0.1309 (SRHA) and 0.0074 (FA), respectively. CeO, CeH, CeOeC, and MeeOH were involved in the interaction between NOM and AgNP. The NOM decreased the accumulated content of Ag in wheat. Hence, NOM alleviated the inhibition of AgNP to wheat growth. SRHA reduced the Ag content of wheat roots approximately 3-fold. These results clearly indicated the importance of NOM on altering the behavior, fate and toxicity of AgNP in an environment.
关键词： Wheat,Nanoparticle fate,Accumulation,Natural organic matter,Silver nanoparticle
更新于2025-11-19 16:46:39
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Continuous-wave Terahertz Imaging Applied to Detect Infestations Caused by Insects in Grain
摘要： Detection infestations caused by insects in grain are important control measures for ensuring storage longevity, seed quality and food safety. The efficiency of the continuous wave terahertz imaging method to detect infestations caused by insects in wheat kernels was determined in this study. A continuous wave terahertz experimental setup was designed for recording of THz images corresponding to different infestations caused by different life stages of insects. The experimental results indicate that the absorbance is generally highest for un-infested wheat kernels and decreased at later growth stages from THz pseudo-color images. Our study intended to demonstrate how the method of continuous wave Terahertz imaging could be applied to detect Infestations Caused by Insects in Grain.
关键词： terahertz imaging,wheat grain,infestation,insect,Detection
更新于2025-09-23 15:22:29
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Identification of Wheat Yellow Rust Using Optimal Three-Band Spectral Indices in Different Growth Stages
摘要： Yellow rust, a widely known destructive wheat disease, affects wheat quality and causes large economic losses in wheat production. Hyperspectral remote sensing has shown potential for the detection of plant disease. This study aimed to analyze the spectral reflectance of the wheat canopy in the range of 350–1000 nm and to develop optimal spectral indices to detect yellow rust disease in wheat at different growth stages. The sensitive wavebands of healthy and infected wheat were located in the range 460–720 nm in the early-mid growth stage (from booting to anthesis), and in the ranges 568–709 nm and 725–1000 nm in the mid-late growth stage (from filling to milky ripeness), respectively. All possible three-band combinations over these sensitive wavebands were calculated as the forms of PRI (Photochemical Reflectance Index) and ARI (Anthocyanin Reflectance Index) at different growth stages and assessed to determine whether they could be used for estimating the severity of yellow rust disease. The optimal spectral index for estimating wheat infected by yellow rust disease was PRI (570, 525, 705) during the early-mid growth stage with R2 of 0.669, and ARI (860, 790, 750) during the mid-late growth stage with R2 of 0.888. Comparison of the proposed spectral indices with previously reported vegetation indices were able to satisfactorily discriminate wheat yellow rust. The classification accuracy for PRI (570, 525, 705) was 80.6% and the kappa coefficient was 0.61 in early-mid growth stage, and the classification accuracy for ARI (860, 790, 750) was 91.9% and the kappa coefficient was 0.75 in mid-late growth stage. The classification accuracy of the two indices reached 84.1% and 93.2% in the early-mid and mid-late growth stages in the validated dataset, respectively. We conclude that the three-band spectral indices PRI (570, 525, 705) and ARI (860, 790, 750) are optimal for monitoring yellow rust infection in these two growth stages, respectively. Our method is expected to provide a technical basis for wheat disease detection and prevention in the early-mid growth stage, and the estimation of yield losses in the mid-late growth stage.
关键词： yellow rust disease,three-band spectral index,different growth stages,hyperspectral remote sensing,wheat infection
更新于2025-09-23 15:22:29
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Rapid screening of ochratoxin A in wheat by infrared spectroscopy
摘要： The use of infrared spectroscopy for the screening of 229 unprocessed durum wheat samples naturally contaminated with OTA has been investigated. Samples were analysed by both Fourier Transform near- and mid-infrared spectroscopy (FT-NIR, FT-MIR). Partial-Least Squares-Discriminant Analysis (PLS-DA) and Principal Component-Linear Discriminant Analysis (PC-LDA) classification models were used to differentiate highly contaminated durum wheat samples from low contaminated ones and the performances of the resulting models were compared. The overall discrimination rates were higher than 94% for both FT-NIR and FT-MIR range by using a cut-off limit set at 2 μg/kg OTA, independently from the classification model used thus confirming the reliability of the two statistical approaches used. False compliant rates of 6% were obtained for both spectral ranges and both classification models. These findings indicate that FT-NIR, as well as FT-MIR analysis, might be a promising, inexpensive and easy-to-use screening tool to rapidly discriminate unprocessed wheat samples for OTA content.
关键词： Principal component analysis,Screening method,Ochratoxin A,Unprocessed wheat,FT-NIR/MIR spectroscopy,Linear discriminant analysis
更新于2025-09-23 15:22:29
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Proximal fluorescence sensing of potassium responsive crops to develop improved predictions of biomass, yield and grain quality of wheat and barley
摘要： Precision nutrient management requires accurate assessment of crop nutrient status. This is common for assessing N status, but much less so for other nutrients. Because fluorescence can indicate crop stress, the robustness of different fluorescence indices was assessed to predict crop nutrient status (K, Mg and Ca). The hypothesis was that crop nutrition limitations, especially K, can be detected using fluorescence proximal sensing to quantify crop response with a high degree of spatial resolution. A factorial experiment was imposed with four treatment factors: crop, K fertilizer rate, lime and row management. The soil at the experimental site was K deficient and the crop variables showed significant treatment effects (e.g. yield, protein). Fluorescence sensing identified a significant positive K response for three chlorophyll related indices (SFR_G, SFR_R and CHL), but not for FLAV; while wheat was significantly different from barley. Using a k-fold cross-validation method promising predictive relationships were found. The strongest predictions were for SFR_R to predict crop biomass, for SFR_G to predict crop K content of inter-row wheat, for CHL to predict crop Ca content of inter-row wheat and for FLAV with barley grain protein in the windrow treatment. The fluorescence indices produced more significant crop variable predictions than measuring NDVI using an active sensor. This study illustrates the utility of fluorescence sensing to measure chlorophyll related signals for capturing the nutritional status of barley and wheat crops. These results show encouraging potential to rapidly detect crop nutrient status for non-N nutrients using fluorescence sensing.
关键词： Biomass,Wheat,Fluorescence indices,Chlorophyll,Grain quality prediction,Barley
更新于2025-09-23 15:22:29
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Vis- and NIR-Based Instruments for Detection of Black-Tip Damaged Wheat Kernels: A Comparative Study
摘要： Black-tip (BT) is a non-mycotoxic fungus that attacks wheat kernels, forming a dark brown or black sooty area at the tip of the kernel. Visual inspection, which is the approved reference method for determining the amount of BT in wheat, requires substantial time and has high potential for subjective evaluation. Three spectrometers covering the spectral ranges 950-1636 nm (Spec1), 600-1045 nm (Spec2), and 380-780 nm (Spec3) were evaluated for their ability to predict the presence of BT. Kernels were quantified into four levels: (A) sound, (B) low black-tip symptoms (BTS), (C) high BTS, and (D) BT damaged (BTD). Discriminant classification models were developed to evaluate combinations of levels. The combinations were (1) levels A, B, C, and D separately; (2) A, B+C, and D; and (3) A+B and C+D. Spectral data for 2,760 kernels obtained from 23 hard red winter (HRW) wheat samples, each comprising 30 kernels that were visually selected for each of the four levels of black-tip severity (A, B, C, and D), were collected with each spectrometer. Discriminant calibration models for each spectrometer and classification category were developed based on (1) three combinations of 17 HRW wheat samples, with the six remaining samples used for independent validation, and (2) combinations of 20 randomly selected kernels from each of the 23 HRW wheat samples as calibration samples, with the remaining ten kernels used as validation samples. Discriminant analysis was based on five wavelengths for each model. Spectra pretreatment was the standard normal variate (SNV). Results showed that all three spectrometers were capable of detecting BT damage on wheat kernels. BT classification accuracy was observed to have been affected by wheat varieties for Spec1 and Spec2 (both with NIR wavelengths) but not for Spec3, which was entirely in the visible region. The two-category classification (A+B, C+D) provided higher accuracy than the three-category (A, B+C, D) and four-category (A, B, C, D) classifications. Based on the percent correct classification and Youden’s index, Spec2 performed better in detecting sound and BTD wheat kernels, with classification accuracies of the best two-category classification calibration model ranging from 85.6% to 87.5%, compared to Spec1 at 74.8% to 78.4% and Spec3 at 76.7% to 79.2%. This study also showed the potential of using a five-wavelength model, which equates to the potential for developing simple, less expensive, high-speed photoelectric detection instruments. These instruments can serve as important tools in plant breeding, grading, or grain processing facilities to enable BT detection and, with proper selection of wavelengths, may also find applications in simultaneous single-kernel detection, measurement, and segregation of other chemical characteristics, such as protein and starch content.
关键词： Black-tip damage,Wheat,VIS,NIR,Spectroscopy
更新于2025-09-23 15:21:01
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Inactivation of Salmonella and Quality Changes in Wheat Flour after Pulsed Light-Emitting Diode (LED) Treatments
摘要： Several low water activity (aw) foods have been recently associated with Salmonella related outbreaks and recalls. The use of high intensity light pulses generated by light-emitting diodes (LEDs) is a novel approach to achieve microbial inactivation. This study compares the ability of light emitted by LEDs at wavelengths of 275, 365, 395, and 455 nm to inactivate microorganisms at different environmental relative humidity (RH) conditions. The exposure to LED radiant energy of 1199 J/cm2 at wavelengths of 365, 395, and 455 nm resulted in Salmonella reductions of 2.22, 2.48, and 1.61 logs CFU/g, respectively. Reductions in Salmonella cell counts of 1.07, 2.42, 3.67, and 2.64 CFU/g were observed in wheat flour after 60 min of 275, 365, 395, and 455 nm LED treatments, respectively, at 25°C and an RH of 75%. Significant drying, oxidation of gluten proteins, and changes in the secondary structure of gluten were observed after LED treatments at all the light wavelengths tested. Significant color change of wheat flour was observed for all wavelengths LED except 275 nm. The results of this study will aid selection of LED wavelengths appropriate for inactivating microorganisms in low aw foods. This study presents the potential of LED treatment for simultaneous drying and microbial decontamination of foods.
关键词： gluten oxidation,Salmonella,light-emitting diodes,low water activity foods,microbial inactivation,wheat flour
更新于2025-09-23 15:19:57
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Effect of low power laser irradiation on bio-physical properties of wheat seeds
摘要： The production of quality food is indispensable and essential to overcome its global shortage. In order to exercise the facile route to acquire massive production, a laser irradiation treatment method was established. We have investigated the effects of diode laser irradiation on wheat seeds germination, its early growth and biochemical parameters. The variation in germination parameters, caused by laser treatment were monitored carefully. A comparison study was accomplished to examine the laser irradiation effects on treated and control seeds. The red laser indicated an enhancement of 25% in germination percentage, 4.68 cm in shoot length, and 0.64 cm in root length while green laser showed 6.25% less germination percentage than the untreated seeds. Further green laser showed 9.67 cm increase in shoot length, 5.39 cm in root length as compared to untreated seeds. It was found that the seeds which were irradiated with green laser showed an amount of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), of 11.9, 10, and 1.53 per mg of protein, respectively as compared to control seeds. Thus, these investigations are promising and suitable for upcoming research on a large scale.
关键词： Wheat,Biochemical parameters,Protein,Germination parameter,Diode laser
更新于2025-09-23 15:19:57
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Inactivation of Salmonella spp. in Wheat Flour by 395 nm Pulsed Light Emitting Diode (LED) Treatment and the Related Functional and Structural Changes of Gluten
摘要： Salmonella spp. is one of the top foodborne pathogens associated with low-moisture foods and they exhibit significant resistance to conventional thermal treatments. UV light pulses emitted from light emitting diode (LED) has shown antimicrobial potential in high-moisture foods and water. However, limited information is available about the antimicrobial potential of UV light with different wavelengths, including 395 nm in low-moisture foods. The objectives of this study were to investigate the antimicrobial potential of 395 nm pulsed LED light in wheat flour and the resulting quality changes. This study demonstrated a maximum 2.91 log reduction of Salmonella cocktail in wheat flour treated with 395 nm pulsed LED for 60 min in a semi-closed system. Oxidation occurred in wheat flour after 30 and 60 min exposure to the 395 nm LED, which subsequently led to bleaching, and polymerization of gluten components through disulphide linkage. The water holding capacity of gluten was reduced by oxidation, and the contents of secondary structures were altered significantly after pulsed LED treatment, but the rheological properties were not deteriorated. The disulfide bond formation naturally happens during dough formation and the oxidation triggered by pulsed LED treatment may play a role on accelerating this process. The 395 nm pulsed LED treatment could be a promising decontamination technology for wheat flour with an additional benefit of bleaching of the flour without chemicals.
关键词： Salmonella,oxidation,wheat flour,UV-A,light emitting diode (LED),Low-moisture foods
更新于2025-09-19 17:13:59
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Cold plasma treatment and laser irradiation of <i>Triticum</i> spp. seeds for sterilization and germination
摘要： In this research work, plasma and laser-based treatments have been applied on wheat seeds to improve their growth and development. Plasma treatment modi?ed the surface morphology of seed which enhanced the germination rate and also exhibited great immunity against fungus; only 20% seeds are a?ected by fungus as compared to the untreated sample. In addition, an increase in protein concentration in plasma treated seeds has also been observed. In the laser treatment, laser pulses have been exercised on wheat seeds, while seeds were also exposed in argon plasma generated at di?erent applied voltages and exposure times. This laser treatment lessens germination time, increases water absorption, and abolishes disease development from seed borne fungi that are present on or within seeds. Thus, it is observed that the use of plasma and laser radiation on the seeds made productive e?ects on the growth parameters and may be the alternative source for the presowing seed treatment.
关键词： microbial inactivation,food chemistry,wheat seeds,plasma chemistry,plant biotechnology,cold plasma,germination
更新于2025-09-19 17:13:59