Pesticides In Food Products Research Articles

Biocontrol of common scab in potato cultivation

Biocontrol of common scab in potato cultivation

Synthesis of Polyoxometalates-Ionic Liquids@Fe3O4@SiO2 composites for the extraction of atrazine and deltamethrin pesticides residues from food samples and their determination by HPLC

The excessive use of pesticides in food production has adverse effects on both the environment and human health. In the present study, atrazine and deltamethrin were employed as pesticides in the cultivation of tomatoes, cucumbers, and brinjal. The HPLC method was utilized for thesimultaneous determination of these two pesticides, employing a cleanup approach based on polyoxometalates (POMs)ionic liquids magnetic nanocompositesCuILPOM-Fe3O4@SiO2 and ZnILPOM-Fe3O4@SiO2. These magnetic nanocomposites were synthesized and subjected to comprehensive characterization using various analytical techniques, including fourier-transform infrared spectroscopy(FT-IR), UV–visible spectroscopy, powder X-ray diffraction(P-XRD),transmission electron microscope(TEM),scanning electron microscopy (SEM) and energy dispersive X-rays spectroscopy (EDX),thermogravimetric analysis (TGA), and rheology. Thedispersive solid-phase extraction (d-SPE) method was effectively employed for the extraction of pesticidesresidues using CuILPOM-Fe3O4@SiO2 and ZnILPOM-Fe3O4@SiO2. Under the optimized conditions, the linear concentration ranges for atrazine and deltamethrin were found to be 0.01–100.0 µg/L and 0.05–100 µg/L, respectively. The coefficient of determination (R2) for both compounds was notably high at 0.997 and 0.994, respectively. The limit of detection (LOD) ranged from 0.01 µg/L to 0.05 µg/L, and the relative standard deviations (RSDs) fell within the range of 5.1 % to 7.2 %. Ultimately, the method's performance in various food samples was assessed, resulting in satisfactory recoveries ranging from 80.9 % to 98.6 %.

Gas Chromatographic Determination of Residual Concentrations of a Mixture of Organochlorine Pesticides in Food Products

Purpose of research. The aim of the work is to optimize the conditions for gas chromatographic determination of a mixture of eight organochlorine pesticides: aldrin, hexachlorobenzene, heptachlor, α-hexachlorocyclohexane, γ-hexachlorocyclohexane, dichlorodiphenyltrichloromethylmethane, dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene.Methods. For chromatographic studies of organochlorine pesticides we used a Shimadzu GC-2010Plus gas chromatograph (Shimadzu, Japan) equipped with an automatic equilibrium vapor sample dispenser NT200N, electron-capture detector based on 63Ni and quartz capillary nonpolar column "Chromatek" SPB-5 (30 m, 0.32 mm, film thickness on the basis of phenyl(5%) and dimethyl(95%) polysiloxanes 0.5 μm) with an operating temperature range of 60°C 320/340°C. The chromatograms were processed in the application LabSolutions GPC.Results. On the basis of experimentally obtained data the optimal conditions for gas chromatographic determination and separation of eight-component mixture of organochlorine pesticides were selected, namely: the value of mobile phase flow division 1:10, carrier gas flow rate – 1.0 ml/min, two-stage temperature programmable column mode from 160 to 240°C with the rate of increase of 5°C/min. The metrological characteristics of the analysis and validation of the results of the proposed technique with the method of high-performance liquid chromatography were evaluated. Good reproducibility of chromatography results with the possibility of detection of organochlorine pesticides at the level of 10-6 – 10-5 μg/cm3 was proved. Application of Fisher's test has shown absence of significant differences in reproducibility of sampled populations the investigated methods of chromatographic analysis of COPCs are equally accurate. Extraction sample preparation of samples of real objects was proposed, the calculated extraction degrees >84% allow to recommend the technique for quantitative determination of analytes.Conclusion. The method of gas chromatographic analysis was tested for determination of organochlorine pesticides in samples of drinking water and baby puree (Russia) by additive method. Exceeding the norms of residual contents of organochlorine pesticides in the samples of the food products under study was not detected.

New approaches to the determination of organochlorine pesticides in food products and food raw materials

Introduction. The current methods for determining the residual amounts of organochlorine pesticides – 4,4-dichlorodiphenyltrichloromethylmethane (DDT) and its metabolites, hexachlorocyclohexane (HCH) (α, β, γ isomers) in food products and food raw materials, subject to mandatory declaration for their content, despite a fairly high sensitivity, are characterized by low measurement selectivity and are based on the use of obsolete equipment, time-consuming sample preparation. 
 Material and methods. In the work, the method of gas chromatography with mass spectrometric detection on a gas chromatograph “Khromatek-Kristall 5000.2” was used. Sample preparation was carried out by the method of matrix solid-phase dispersion, based on the destruction and dispersion of the analysed sample together with florisil in order to obtain a free-flowing dry mixture.
 Results. The effectiveness of the method has been proven by validation on 16 model samples of food products of animal origin of various compositions. The versatility of the analysis procedure is ensured by the systematization of food products according to their structural and mechanical properties into groups: liquid, having a finely dispersed structure and a high water content (group A); viscous and pasty products having a fine structure (group B); products of animal origin requiring grinding and dispersion (semi-solid and solid), having a high water and/or fat content, not free-flowing (Group B); dry products of animal origin (dried or freeze-dried), and/or free-flowing powdered products with a low water content that require wetting, grinding and dispersion (Group D). Ingredient composition (water, fat, protein, hydrocarbons) does not significantly affect the stability and reproducibility of the developed method.
 Limitations. The method has been tested and validated on samples of food products of animal origin. 
 Conclusion. The developed method for the determination of DDT and its metabolites, HCH (isomers α, β, γ), providing a range of measured concentrations (0.01–1.0 mg/kg) will make it possible to control the content of substances in all groups of food products of animal origin identified in the TR CU 021/11 “On food safety”, including products for baby food.

Biochemical and Biotechnological Insights into Fungus-Plant Interactions for Enhanced Sustainable Agricultural and Industrial Processes.

The literature is full of studies reporting environmental and health issues related to using traditional pesticides in food production and storage. Fortunately, alternatives have arisen in the last few decades, showing that organic agriculture is possible and economically feasible. And in this scenario, fungi may be helpful. In the natural environment, when associated with plants, these microorganisms offer plant-growth-promoting molecules, facilitate plant nutrient uptake, and antagonize phytopathogens. It is true that fungi can also be phytopathogenic, but even they can benefit agriculture in some way-since pathogenicity is species-specific, these fungi are shown to be useful against weeds (as bioherbicides). Finally, plant-associated yeasts and molds are natural biofactories, and the metabolites they produce while dwelling in leaves, flowers, roots, or the rhizosphere have the potential to be employed in different industrial activities. By addressing all these subjects, this manuscript comprehensively reviews the biotechnological uses of plant-associated fungi and, in addition, aims to sensitize academics, researchers, and investors to new alternatives for healthier and more environmentally friendly production processes.

Switchable hydrophilicity solvent-based microextraction coupled with fluorescent detection of dichlorvos

The risk of the hazardous pesticide dichlorvos (DDVP) entering the human body through aquatic products is causing concern as global demand for aquatic products increases. Herein, a novel approach ground on switchable hydrophilicity solvent-based microextraction coupled with fluorescent detection of DDVP in aquatic products was established. Sodium nonanoate, a switchable hydrophilic solvent, was converted into nonanoic acid in-situ for use as an extractant under acidic conditions to extract DDVP from aquatic products. Thereafter, DDVP was hydrolyzed to dichloroacetaldehyde (DCA) by adjusting the extraction solution to an alkaline condition. The fluorescent substances were generated due to the condensation reaction of DCA and resorcinol which can achieve the quantification of DDVP. The assay had a linear relationship between 40 and 280 μg kg−1, with a limit of detection of 2.4 μg kg−1. The assay has been used to determine the residual content of DDVP in grass carp, sea cucumber, and abalone samples. The recoveries ranged from 93.8% to 106%. The strategy integrating microextraction and detection offers insight into monitoring pesticides in food products.

Sınıf Eğitimi Öğrencilerinin Çevrimiçi Forum Destekli Sosyobilimsel Konulara İlişkin Muhakemelerinin İncelenmesi

This study aims to scrutinize the reasoning skills of primary education students studying at the 1st. grade in socio-scientific issues supported with online form. This study was carried out during the environmental education course of the first grade in the 2020-2021 Academic Year Spring Term at Dicle University. The online environmental education course discussed agricultural issues, genetically modified organisms (GMO), using pesticides in food production, importing plastic waste, and using rock gas as an alternative energy source. Within the scope of the research issues, the scenarios and articles with the socio-scientific theme were uploaded to the automation system of the university and were discussed by the students for two weeks. Afterwards, the students completed the process by participating in an online debate form which included scenarios with socio-scientific issues. The students' views on socio-scientific matters were analyzed by the complexity, multidimensionality, questioning, and suspiciousness subscales. Findings were presented in accordance with social, economic, ecological and health domains. As the result of the research, the students accepted that GMO products would lead to several health problems, while they expressed that the GMO products could be used to survive. The students put forward that using GMO products had to be controlled by the authorities. Most of the students indicated that it was required to produce recyclable plastic instead of importing plastic waste and improving environmental waste management systems. They also determined that using rock gas as an energy source would bring about environmental pollution; alternative energy sources would be prefered rather than rock gas. Furthermore, they expressed that using pesticides could damage nature and the environment; however, pesticides could reproduce durable plant species if taken necessary precautions.

Intoxication symptoms and health conditions of family farmers associated with the use of pesticides: a study conducted in Zona da Mata Mineira, Brazil

This study aimed to evaluate the association between the use of pesticides, symptoms of intoxication and health conditions of family farmers in the Mata Mineira area, Brazil. This is a cross-sectional study with 48 family farmers from a municipality in the Zona da Mata, Minas Gerais. A semi-structured questionnaire was applied to obtain demographic, socioeconomic information and characterization of the use of pesticides. Blood samples were collected from farmers for biochemical tests and evaluation of markers of exposure to pesticides. It was found that 75% of farmers used pesticides in food production, most of these products being extremely toxic. These farmers showed changes in plasma cholinesterase, erythrocyte cholinesterase and butyrylcholinesterase, markers of exposure to pesticides. There was an association between spraying for more than 4 hours/day and reporting of acute symptoms of intoxication, as well as between the use of pesticides and the presence of chronic non-communicable diseases. Multivariate analysis indicated that non-compliance with the period of re-entry into crops after the use of pesticides remained as an explanatory variable for lung disease. We infer that acute symptoms, as well as chronic non-communicable diseases reported by family farmers, may be associated with the use of pesticides.

Modern Analytical Methods for the Analysis of Pesticides in Grapes: A Review.

Currently, research on the determination of pesticides in food products is very popular. Information obtained from research conducted so far mainly concerns the development of a methodology to determine the content of pesticides in food products. However, they do not describe the content of the pesticide used in viticulture in the resulting product. Over the past decade, this study has examined analytical methodologies for assessing pesticide residues in grapes. Scopus, Web of Science, Science Direct, PubMed, and Springer databases were searched for relevant publications. The phrases “pesticides” and “grapes” and their combinations were used to search for articles. The titles and annotations of the extracted articles have been read and studied to ensure that they meet the review criteria. The selected articles were used to compile a systematic review based on scientific research and reliable sources. The need to study the detection of pesticide residues in grapes using advanced analytical methods is confirmed by our systematic review. This review also highlights modern methods of sample preparation, such as QuEChERS, SPME, PLE, dLLME, and ADLL-ME, as well as the most used methods of separation and identification of pesticides in grapes. An overview of the countries where residual grape pesticide amounts are most studied is presented, along with the data on commonly used pesticides to control pests and diseases in grape cultivation. Finally, future possibilities and trends in the analysis of pesticide residues in grapes are discussed by various analytical methods.

Optimization of hyperspectral systems of fluorescent testing of food products

Spectral analysis – based on the study of the emission spectra of various substances. Samples of the analyzed substance are “burned” under certain conditions, the substance evaporates and dissonates into atoms, which, when excited, give a spectrum. The light emitted in this case, passing through the glass prism of the spectroscope, is decomposed into its constituent parts (different light) and the experimenter observes a number of different lines (linear spectrum). The lines judge the presence of a particular element in the analyzed product.
 The higher the intensity of the lines, the higher the concentration of the substance. With the help of spectrographs, it is possible to photograph the radiation and, by the degree of blackening of the lines on the photographic plate, determine the concentration of a substance. The method is highly sensitive; impurities of substances determine up to 0.0001% – decimal fractions of a percent. The method is used to determine the mineral composition of products of plant and animal origin.
 Luminescence is the glow of atoms, ions, molecules, and more complex particles of matter, which occurs as a result of the transition of electrons in them upon returning from an excited state to a normal one. To transfer particles to an excited state, the definition of the amount of energy is summed up. Glow or part of the energy is released in the form of luminescence quanta. This method is used to determine vitamins, proteins, and fats in milk, to determine the freshness of meat and fish and various spoilage of vegetables, fruits, to detect preservatives, drugs, carcinogens, pesticides in food products.
 When assessing the quality of food products, great importance is given to their consistency. There are rheological methods for assessing consistency – the primary assessment of food products. Rheology studies the structural and mechanical properties of materials (deformation). Rheological properties include viscosity, elasticity, elasticity, and strength.
 Perhaps the emergence of new, more advanced methods that will become widespread, i.e., each consumer will have the opportunity to determine the quality of the product with the help of a mini device (such as a radioactive background meter, etc.) when buying.

Detection of pesticides in food products using paper-based devices by UV-induced fluorescence spectroscopy combined with molecularly imprinted polymers

In this proof-of-concept study, we explore the detection of pesticides in food using a combined power of sensitive UV-induced fingerprint spectroscopy with selective capture by molecularly imprinted polymers (MIPs) and portable cost-effective paper-based analytical devices (PADs). The specific pesticides used herein as model compounds (both pure substances and their application products for spraying), were: strobilurins (i.e. trifloxystrobin), urea pesticides (rimsulfuron), pyrethroids (cypermethrine) and aryloxyphenoxyproponic acid herbicides (Haloxyfop-methyl). Commercially available spraying formulations containing the selected pesticides were positively identified by MIP-PADs swabs of sprayed apple and tomato. The key properties of MIP layer – imprinting factor (IF) and selectivity factor (α) were characterized using trifloxystrobin (IF-3.5, α-4.4) was demonstrated as a potential option for in-field application. The presented method may provide effective help with in-field testing of food and reveal problems such as false product labelling.

Suspect screening and untargeted analysis of veterinary drugs in food by LC-HRMS: Application of background exclusion-dependent acquisition for retrospective analysis of unknown xenobiotics

The presence of veterinary drug and pesticide residues in food products pose considerable threats to human health. Monitoring of these residues in food is mainly carried out using targeted analysis by triple quadrupole mass spectrometry. However, these methods are not suitable for suspect screening and untargeted analysis of unknowns. The main objectives of this study were to develop a new high-resolution mass spectrometry (HRMS)-based analytical strategy for retrospective analysis of suspect and unknown xenobiotics and to evaluate its performance in the tentative identification of 48 veterinary drugs as “unknowns” spiked in a pork sample. In the analysis, a newly developed background exclusion data-dependent acquisition (BE-DDA) technique was employed to trigger the product ion (MS/MS) spectral acquisition of the “unknowns”, and an in-house precise-and-thorough background-subtraction (PATBS) technique was applied to detect these “unknowns”. Results showed that untargeted data mining of the acquired LC-MS dataset by PATBS was able to find all the 48 veterinary drugs and 46 of them were triggered by BE-DDA to generate accurate MS/MS spectra. The dataset of recorded accurate full-scan mass and MS/MS spectra of all the xenobiotics of the test pork sample is defined as the xenobiotics profile. Searching the xenobiotic profile of the test pork sample using mass spectral data of selected veterinary drugs (as suspects) from the mzCloud spectral library led to the correct hits. Searching against the mzCloud spectral library using the mass spectral data of selected individual veterinary drugs (as unknowns) from the xenobiotics profile tentatively confirmed their identities. In contrast, analysis of the same sample using ion intensity-data dependent acquisition only recorded the MS/MS spectra for 34 veterinary drugs. In addition, a data independent acquisition method enabled the acquisition of the fragment spectra for 44 veterinary drugs, but their spectral data displayed only one or a few true product ions of individual analytes of interest along with many fragments from coeluted biological components and background noises. This study demonstrates that this analytical strategy has a potential to become a practical tool for the retrospective suspect screening and untargeted analysis of unknown xenobiotics in a biological sample such as veterinary drugs and pesticides in food products.

Red de comercialización y uso de plaguicidas en el partido de Tandil, sector del sudeste de la provincia de Buenos Aires, Argentina

Agricultural activity is an engine of the Argentine economy, and given the extensive use of pesticides in food production, it is essential to understand their handling to assess their effects on the environment and people's health. The objective was to know the main aspects of the network of actors that use and commercialize pesticides in the Tandil district (Buenos Aires) during 2019 and 2020. Qualified referents were interviewed and agricultural producers in the area were surveyed. 10 main actors were identified, grouped into 3 categories (government agencies, civil and private associations) which proved to be linked through activities such as control, training or trade flows. The key actors agreed on the scarcity of resources assigned to control, the low use of the agronomic recipe and the diverse final destination of the empty drums. Added to this, the anthropocentric look in relation to nature, the lack of professional advice in the fields, and distrust in agroecological production is evident. The need to incorporate new actors into the network, generate public policies that allow greater control, and the urgency of undergoing a change in the productive paradigm is concluded.

ЕКОЛОГІЧНІ НАСЛІДКИ ЗАСТОСУВАННЯ ПЕСТИЦИДІВ У КОНТЕКСТІ ВПЛИВУ НА ЛЮДИНУ

Purpose.An urgent problem is to provide the population with high quality food. Pesticides are used in order to im- prove the quality of plant raw materials and preserve landscape and biological diversity. Findings.It has been estab- lished that pesticides in food in most cases are not found as single substances, but as a combination of several ingredi- ents, which leads to a synergistic effect on human health. This causes some difficulties in normalizing the content of such combinations. Methodology. The basis for ensuring food safety is to control the pesticide content in them. For this purpose, we used the methods of modern ecological chemistry. Results. It was found that the determination of pesti- cides in the laboratory in this way is too expensive, which prompted the use of the calculation method. The calculations of time-permissible concentrations (TPC) of pesticides in food products on the basis of average indicators depending on the toxicity index LD50, as well as MPCv for organochlorine and organophosphorus pesticides, based on their chemical properties. The dependence between toxicity, selectivity of action and TPC is established, which is confirmed by the correspondence of TPC values determined experimentally and by calculation; differences in the results of studies do not exceed ± 0.07 mg per 1 kg of product. Originality.It has been proven that the obtained TPC values for different catego- ries of products are sufficient, except for some products of fish and meat and dairy origin. It is proposed to classify them as high risk due to the high content of pesticide residues and to strictly control the content of the latter. Practical value. The obtained results make it possible to significantly simplify the establishment of MDR indicators for food products based on the content of pesticide residues.

Pesticide Residues in Pineapple Juice in Abidjan, Cote D’ivoire

The determination of pesticides in food products is an essential issue to guarantee food safety and minimize health risks of consumers. In this study, 30 pineapple juice samples were collected randomly from 30 seller through the city of Abidjan (Côte d’Ivoire) and analyzed for the determination of pesticide residues. The aim of the work was to quantify 30 commonly used pesticides (Metolachlor, Chlorpropham, Parathion-methyl, Chlorfenvinphos, Vinclozolin, Parathion-ethyl, Fenuron, Aldicarb, Metoxuron, Monuron, Methabenzthiazuron, Chlortoluron, Monolinuron, Isoproturon, Diuron, Metobromuron, Metazachlor, Buturon, Linuron, Prometryn, Terbutryn, Desisopropylatrazine, Desethylatrazine, Simazine, Cyanazine, Atrazine, Propazine, Terbuthylazine, Metamitron, Crimidine and Metolachlor) in real samples of pineapple juice. The method used for the determination of these analytes in the complex matrices was high-performance liquid chromatography with UV/Visible detector. Results obtained indicate that 30% of the investigated pineapple juices samples are free of pesticides residues or have a level below Limit Of Detection......

Comprehensive assessment of unutilized and obsolete pesticides impact on genetic status and health of population of Almaty region

The group of persistent organic pollutants (POPs) are particularly dangerous for the environment and by consequence for human health because of the risk to be transmitted in the food chain. Among them, the urgent problem of obsolete and forbidden organochlorinated pesticides (OCPs) needs a rigorous management in many countries, including Kazakhstan.The aim of our study was to evaluate the effect of pesticides content in food products on the genetic status and health of the population living on the contaminated areas near destroyed warehouses for OCPs (4 villages of Talgar district and 1 control site, Almaty region).The food products sampled in Taukaraturyk (control site), and in 4 villages where non-utilized obsolete pesticides were discovered: Beskainar, Kyzylkairat, Amangeldy, and Belbulak. The contents of 24 pesticides in food products from plant (apples, pears, tomatoes, cucumbers, sweet peppers) and animal (beef meat, cow milk, honey) origin, that grown in places of localization of non-utilized OCPs, were determined, sometimes in high and unacceptably high concentrations (before 2500 times over MRL). In pears, the pesticides content (especially DDT, γ-HCH, β-HCH, endosulfan, and aldrin pesticide group), was higher than in other fruits. Among vegetables, the highest levels of all groups of pesticide were found in cucumbers. Beef meat samples demonstrated increased contents of β-HCH, γ-HCH, endrin and dieldrin. In cow milk samples only the high concentration of dieldrin was found. The content of pesticides in meat was 4–5 times higher than in milk. The medical examinations, carried out among the cohorts living around the polluted by pesticides territories and control cohort from ecologically favorable village, showed that there were more individuals with high and middle levels of somatic health in the control group than in groups exposed to OCPs. The long-term effect of the pesticide contamination of the environment on genetic status of the population was assessed by chromosomal aberration (CA) frequencies. The highest level of chromosomal aberrations was identified for the examined residents of Kyzylkairat (41%) and Belbulak (38%), a high level in Amangeldy (12%), and middle level in Beskainar (6.5%). The association between the CA frequency, health status and the pesticides contents in food were assessed by a Spearman rank correlation. The low indicators of somatic health status were strictly associated with high levels of CA, and good health status indicates that the CA rates did not exceed the spontaneous level of mutagenesis. The strongest correlation was shown between high levels of chromosomal aberrations and the content of different pesticides in pears (Cr = 0.979–0.467), tomatoes (Cr = 0.877–0.476), cucumbers (Cr = 0.975–0.553) and meat (Cr = 0.839–0.368). The obtained results highlight the need to improve health protection by increasing the public awareness to the security of the storage of obsolete OCPs in order to strengthen food safety by efficient control services.

Assessment of Antimicrobial and Pesticide Residues in Food Products Sourced from Peasant Family Farming in Chile

The presence of antimicrobial and pesticide residues in products sourced from peasant family farms selected from eight regions of Chile was determined. A total of 204 samples were analyzed from family farm products, including honey, lettuce, tomato, strawberry, raspberry, lamb meat, and cow's milk. Pesticide residues were found in 43 of 107 samples tested for them, but only 4 samples had concentrations that exceeded the maximum residue limits (MRLs) set by Chilean regulations. As for animal products, 2 of 15 cow's milk samples tested positive for permethrin residues; however, these concentrations did not exceed Chilean MRLs. No pesticide residues were detected in honey samples. As for antimicrobial drugs, 4 of 14 lamb meat samples and 11 of 79 cow's milk samples tested positive for different classes of antimicrobial residues, such as tetracyclines, macrolides, aminoglycosides, and β-lactams. Among these, only three samples exceeded the MRLs for these matrices. Traces of tetracyclines and sulfonamides were detected in 7 of 29 honey samples. These findings show that these chemical contaminants are present in trace concentrations in foodstuffs produced by peasant family farms in Chile; however, most residues did not exceed the regulatory limits. This study is the first assessment of the presence of residues from antimicrobial drugs and pesticides in food products sourced from peasant family farms in Chile. Data about the current state of drug residues in this segment of food products provide a baseline for efforts to close possible gaps in current surveillance schemes.

Antifungal activity of medicinal plant extracts for potential management of Fusarium pathogens

Yield losses due to fungal attacks, post-harvest losses and food spoilage, amongst others present a challenge to food security. There is an ongoing need and search for accessible, affordable and environmentally-friendly alternatives to the use of synthetic pesticides in food production. The aim of this study was to search for affordable potent plant extracts that can be used in smallholder farming system to manage Fusarium related diseases. Extracts from 11 medicinal plant species previously screened against human and animal pathogens in the literature were selected and investigated for their in vitro antifungal activity against five economically important phytopathogenic Fusarium species. Dried leaf powders were extracted with solvents of different polarity and evaluated for antifungal activity using a microdilution method. At least, one of the solvent extracts obtained from a minimum of three plant species demonstrated very strong activity with minimum inhibitory concentration (MIC) less than 0.1 mg/ml against F. equisite, F. oxysporum, F. semitectum, F. chlamydosporum and F. subglutinans. Acetone and ethyl acetate solvent extracts were found in most cases to exhibit stronger antifungal activity compared to water and petroleum ether extracts. However, water extract of Combretum molle was particularly noteworthy as it demonstrated antifungal activity against the tested five Fusarium species. The use of medicinal plant extracts as an antifungal agent presented a cheap, accessible and sustainable source of eco-friendly pesticides useful for crop protection in organic cultivation and small-holder farming.

Facile synthesis of cellulose nanofiber nanocomposite as a SERS substrate for detection of thiram in juice

There has been growing interest in the use of nanocellulose-based substrate for surface-enhanced Raman spectroscopy (SERS) applications. This study aimed to use cellulose nanofibers (CNF) to develop novel CNF-based nanocomposite as a SERS substrate. CNF were cationized with ammonium ions and then interacted with citrate-stabilized gold nanoparticles (AuNPs) via electrostatic attraction to form uniform nanocomposites. The CNF-based nanostructures were loaded with AuNPs that were firmly adhered on the CNF surfaces, providing a three-dimensional plasmonic SERS platform. A Raman-active probe molecule, 4-aminothiophenol, was selected to evaluate the sensitivity and reproducibility of CNF-based SERS substrate. The intensity of SERS spectra obtained from CNF/AuNP nanocomposite was 20 times higher than that from the filter paper/AuNP substrate. The SERS intensity map demonstrates good uniformity of the CNF/AuNP substrate. CNF/AuNP nanocomposites were used in rapid detection of thiram in apple juice by SERS and a limit of detection of 52 ppb of thiram was achieved. These results demonstrate that CNF/AuNP nanocomposite can be used for rapid and sensitive detection of pesticides in food products.

Food contaminated by pesticides: a Brazilian situation overview

Consumers are becoming increasingly demanding about products quality, including new decision variables at their purchases time. Information on nutritional aspects and the use of pesticides has changed consumer preferences. The new information strategies emerged in response to new consumer’s behavioral characteristics and new competition characteristics of the food market. These strategies privilege the use of quality signals, such as labeling, traceability, certification, brand names and adoption of minimum quality standards. The main feature of Brazilian markets is the lack of minimum standards and strong information asymmetries. The market for fresh food is affected by the indiscriminate use of pesticides. The information analysis gathered by the Program for Pesticide Residue Analysis in Food (PARA) found a very worrying situation in Brazil. In this sense, with this paper, our aim is to bring more information about the pesticides contamination in the fresh food markets in Brazil. Transaction Cost Economics is adopted as a theoretical framework to examine the coordination among the agents on the chain and seek sustainable alternatives to reduce the excessive use of pesticides in food production.