Comparison of volatile compounds and sensory profiles of low-alcohol pear beverages fermented with Saccharomyces cerevisiae and different non-Saccharomyces cerevisiae.

This study aimed to assess the impact of Saccharomyces cerevisiae and different non-Saccharomyces cerevisiae (Zygosaccharomyces bailii, Hanseniaspora opuntiae and Zygosaccharomyces rouxii) on the volatile compounds and sensory properties of low-alcohol pear beverages fermented from three varieties of pear juices (Korla, Laiyang and Binzhou). Results showed that all three pear juices were favorable matrices for yeasts growth. Non-Saccharomyces cerevisiae exhibited a higher capacity for acetate ester production compared to Saccharomyces cerevisiae, resulting in a significant enhancement in sensory complexity of the beverages. PCA and sensory analysis demonstrated that pear varieties exerted a stronger influence on the crucial volatile components and aroma characteristics of the fermented beverages compared to the yeast species. CA results showed different yeast strains exhibited suitability for the fermentation of specific pear juice varieties.

Nanoparticle-mediated calmodulin dsRNA and cyantraniliprole co-delivery system: High-efficient control of two key pear pests while ensuring safety for natural enemy insects.

Currently, the predominant method for managing pests in orchards is chemical control. However, prolonged use of chemicals leads to resistance issues and raise ecological safety. A promising approach to tackle these challenges involves nanoparticles-mediated delivery system of dsRNA and pesticides. Despite its potential, this strategy has not been widely applied in controlling pests in pear orchards. In this study, we developed a nanoparticle-mediated ternary biopesticide to tackle resistance and safety concerns associated with calmodulin dsRNA and cyantraniliprole. Initially, we assessed the effectiveness of cyantraniliprole against two key pear pests, Grapholita molesta and Cacopsylla chinensis. Subsequently, we observed an upregualtion of genes CaM and CN following cyantraniliprole treatment. Furthermore, inhibiting or silencing GmCaM and CcGaM enhanced the sensitivity to cyantraniliprole more effectively. By introducing hairpin RNA into the pET30a-BL21 RNaseIII- system to silence GmCaM and CcCaM, we developed a nanoparticle-mediated co-delivery system that exhibited improved control over these two pests. Importantly, our research demonstrated that using reduced cyantraniliprole dosages through ternary biopesticides could help mitigate risks to natural enemies. Overall, our research emphasizes the enhanced effectiveness of ternary biopesticides in boosting the performance of dsRNA and pesticide against pear pests, while fostering environmental sustainability-a novel advancement in this field.

Immobilization of aldo-keto reductase on dopamine/polyethyleneimine functionalized magnetic cellulose nanocrystals to enhance the detoxification of patulin in fresh pear juice.

Patulin (PAT) is a highly toxic mycotoxin, which can contaminate fruits and their products and cause harm to human health. Cellulose nanocrystals (CNCs) were functionalized by magnetite nanoparticles, dopamine (DA) and polyethyleneimine (PEI) to form a multifunctional nanocarrier (DA/PEI@Fe3O4/CNCs) for immobilizing aldo-keto reductase (MgAKR) to degrade PAT. The MgAKR-DA/PEI@Fe3O4/CNCs were reusable and environmentally friendly due to its surface area, high magnetization value, and oxygen/amine function. The immobilization method significantly improved reusability, resistance to proteolysis, temperature stability and storage stability of MgAKR-DA/PEI@Fe3O4/CNCs. With NADPH as a coenzyme, the detoxification rate of MgAKR-DA/PEI@Fe3O4/CNCs on PAT reached 100 % in phosphate buffer and 98 % in fresh pear juice. The quality of fresh pear juice was unaffected by MgAKR-DA/PEI@Fe3O4/CNCs and could be quickly separated by magnet after detoxification, which was convenient for recycling. It has broad application prospects in the control of PAT contamination in beverage products containing fruit and vegetable ingredients.

PpyLTP36 and PpyLTP39 are involved in the transmembrane transport of cuticular wax and are associated with the occurrence of pear fruit russeting.

Non-specific lipid-transfer proteins (nsLTPs) are a group of small, cysteine-rich proteins that are involved in the transport of cuticular wax and other lipid compounds. Accumulating evidence suggests that dynamic changes in cuticular waxes are strongly associated with fruit russeting, an undesirable visual quality that negatively affects consumer appeal in pears. Currently, the regulatory role of nsLTPs in cuticular wax deposition and pear fruit skin russeting remains unclear. Here, we characterized the variations of cuticular waxes in non-treated (russeted) and preharvest bagging treated (non-russeted) pear fruits throughout fruit development and confirmed that the contents of cuticular waxes were significantly negatively correlated with the occurrence of pear fruit russeting. Based on RNA-Sequencing (RNA-Seq) and quantitative real-time PCR (qRT-PCR) analyses, two nsLTP genes (PpyLTP36 and PpyLTP39) were identified, which exhibited high expression levels in non-russeted pear fruit skins and were significantly repressed during fruit skin russeting. Subcellular localization analysis demonstrated that PpyLTP36 and PpyLTP39 were localized to the plasma membrane (PM). Further, transient Virus-Induced Gene Silencing (VIGS) analyses of PpyLTP36 and PpyLTP39 in pear fruits significantly reduced cuticular wax deposition. In conclusion, PpyLTP36 and PpyLTP39 are involved in the transmembrane transport of cuticular wax and are associated with pear fruit skin russeting.

Pear Wood Pyrolysis Influences Quality and Levels of Polycyclic Aromatic Hydrocarbons in Liquid Smoke.

Limu smoked chicken is a traditional Chinese delicacy; however, polycyclic aromatic hydrocarbons (PAHs) are generated during the smoking process. We developed a pyrolysis process for pear wood liquid smoke with minimal PAH generation. Pear wood liquid smoke products were prepared under different pyrolysis conditions in a self-made pyrolysis reactor, and the total phenol, carbonyl compound, total acid, and PAH contents and PAH toxicity risk were evaluated. With increasing temperatures, the toxicity equivalent ΣPAH of the smoke liquid reached 3.004 µg/kg. With increasing particle sizes, the total phenol content reached 1.6 mg/mL; the phenol content was 5.95 mg/mL. With increasing particle sizes, the toxicity equivalent ΣPAHs of the smoke liquor reached 2.441 µg/kg. The optimal parameters for treating pear wood smoke liquid in the thermal reaction device were a pyrolysis temperature of pear wood of >350 °C, particle size of S2, and sucrose content of 8%.

Exploring the wound-healing potential and seasonal chemical variability of the Formosan Callery pear Pyrus calleryana: implications for therapeutic applications.

CONTEXT: Pyrus calleryana Decne (Rosaceae), renowned for its therapeutic properties, is known to moisturize the lungs (removing dryness; relieving cough), clear heat (acting as an antipyretic; febrifuge) and aid in detoxification (relieving pyogenic inflammation; eliminating toxins). However, scientific evidence supporting its efficacy in wound healing is lacking. OBJECTIVE: This study investigated P. calleryana samples collected over a year to explore metabolite variations and their impact on skin wound-healing activities. MATERIALS AND METHODS: P. calleryana (PC) twigs and leaves were collected from the Matsu Islands, Taiwan, spanning 2018-2020. Extracts were prepared using 95% ethanol or water, and we assessed the chemical composition, total phenolic/triterpenoid contents and antioxidant properties. Metabolites were analysed via LC-MS/MS and molecular networking. Wound healing potential was evaluated on WS-1 cells through MTT and migration assays, and gene expression analyses, with tests including control (DMSO), compounds 1 (3'-hydroxylbenzyl-4-hydroxybenzoate-4'-O-ß-glucopyranoside) and 2 (vanilloylcalleryanin) (100 µM), and a positive control (ascorbic acid, 100 µM) for 24 h. RESULTS: Significant variations in extract compositions were observed based on the solvent used, with distinct metabolomic profiles in extracts collected during different months. Notably, compounds 1 and 2 showed no cytotoxic effects on human dermal fibroblast cells and significantly accelerated wound closure at 100 µM. A gene expression analysis indicated upregulation of wound healing-associated genes, including MMP-1 (matrix metalloproteinase-1) and COL1A1 (collagen, type 1, alpha 1). CONCLUSIONS: This study reports the first evidence of PC compounds aiding wound healing. Utilizing Global Natural Products Social Molecular Networking (GNPS) and principal component analysis (PCA) approaches, we unveiled metabolomic profiles, suggesting the potential to expedite wound-healing.

α-Lipoic acid treatment regulates enzymatic browning and nutritional quality of fresh-cut pear fruit by affecting phenolic and carbohydrate metabolism.

Fresh-cut pear fruit is greatly impacted by enzymatic browning, and maintaining quality remains a challenge. This study examined the impact of exogenous α-lipoic acid (α-LA) treatment on enzymatic browning and nutritional quality of fresh-cut pears. Results revealed that 0.5 g/L α-LA treatment effectively maintained color and firmness, and inhibited the increase in microbial number. The α-LA treatment also reduced MDA and H2O2 contents, decreased PPO activity, and enhanced SOD, CAT, and PAL activities. The α-LA treatment notably upregulated phenolic metabolism-related gene expression, including PbPAL, Pb4CL, PbC4H, PbCHI and PbCHS, and then increasing total phenols and flavonoids contents. Furthermore, it also influenced carbohydrate metabolism-related gene expression, including PbSS, PbSPS, PbAI and PbNI, maintaining a high level of sucrose content. These findings indicated that α-LA treatment showed promise in reducing browning and enhancing fresh-cut pears quality, offering a potential postharvest method to prolong the lifespan and maintain nutritional quality.

Synthesis and characterization of Pyrus communis fruit extract synthesized ZnO NPs and assessed their anti-diabetic and anti-microbial potential.

The fruit Pyrus communis, owing to its presence of phenolics and flavonoids, was chosen for its nanoparticle's reducing and stabilizing properties. Furthermore, the zinc metal may be nano-absorbed by the human body. As a result, the study involves synthesizing zinc oxide nanoparticles (ZnO NPs) from P. communis fruit extract using the green method. The synthesized nanoparticle was examined with a UV-visible spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS). When absorption studies were performed with a UV-visible spectrophotometer, the nanoparticle exhibited a blue shift. The FTIR spectrum revealed the molecular groups present in both the fruit extract and metal. In the SEM analysis, the ZnO NPs appeared as spherical particles, agglomerated together, and of nano-size. The larger size of the ZnO NPs in DLS can be attributed to their ability to absorb water. After characterization, nanoparticles were tested for anti-diabetic (α-amylase and yeast glucose uptake activity) and anti-microbial properties. The α-amylase inhibition percentage was 46.46 ± 0.15% for 100 µg/mL, which was comparable to the acarbose inhibition percentage of 50.58 ± 0.67% at the same concentration. The yeast glucose uptake activity was 64.24 ± 0.80% at 20 mM glucose concentration, which was comparable to the standard of 78.03 ± 0.80. The nanoparticle was more effective against Gram-negative bacteria Shigella sp. and Salmonella typhi than against Gram-positive bacteria Bacillus cereus and Streptococcus pneumoniae.

Potential of hyperspectral imaging for nondestructive determination of α-farnesene and conjugated trienol content in 'Yali' pear.

The sesquiterpene α-farnesene and its corresponding oxidation products, namely conjugated trienols (CTols) is well known to be correlated with the development of superficial scald, a typical physiological disorder after a long term of cold storage in pear fruit. In this work, hyperspectral imaging (HSI) technology was used for nondestructive predicting of α-farnesene and CTols [CT258, CT281 and CT(281-290)] content in 'Yali' pear. In order to obtain the best performance of calibration model and simplify the calibration model further, various preprocessing methods together with their combinations and different wavelength selection algorithms, including successive projections algorithm (SPA), competitive adaptive reweighted sampling (CARS) and uninformative variable elimination (UVE), were investigated and compared based on linear partial least square regression (PLSR) and nonlinear least square support vector machine (LS-SVM) models, respectively. In conclusion, compared to the PLSR models, the results of LS-SVM models based on original and preprocessing methods performed better for the prediction of α-farnesene and CTols, while the performance of LS-SVM models based on the selected characteristic wavelengths were worse. For α-farnesene, the best result was obtained by LS-SVM model based on MSC-FD pretreatment with the RPD value of 2.6, Rp = 0.925 and RMSEP = 4.387 nmol cm-2. And for CTols, CT281 performed better compared with CT258 and CT(281-290), achieving the result with RPD = 2.4, Rp = 0.913 and RMSEP = 2.734 nmol cm-2 based on LS-SVM model combined with SD pretreatment. The overall results illustrated HSI technology could be used for rapid and nondestructive prediction of α-farnesene and CTols in 'Yali' pear, which would be helpful for supporting postharvest decision systems.

Health-Related Composition and Bioactivity of an Agave Sap/Prickly Pear Juice Beverage.

In this study, a beverage made from a combination of Agave sap (AS) and prickly pear juice (PPJ) was analyzed for its nutrients and bioactive and potentially health-promoting compounds. The beverage was evaluated for its ability to act as an antioxidant, regulate glycemic properties, and undergo gut bacterial fermentation in vitro. The major mono- and oligosaccharides present in the beverage were galacturonic acid (217.74 ± 13.46 mg/100 mL), rhamnose (227.00 ± 1.58 mg/100 mL), and fructose (158.16 ± 8.86 mg/mL). The main phenolic compounds identified were protocatechuic acid (440.31 ± 3.06 mg/100 mL) and catechin (359.72 ± 7.56 mg/100 mL). It was observed that the beverage had a low glycemic index (<40) and could inhibit digestive carbohydrases. The combination of ingredients also helped to reduce gas production during AS fermentation from 56.77 cm3 to 15.67 cm3. The major SCFAs produced during fermentation were butyrate, acetate, and propionate, with valerate being produced only during the late fermentation of the AS. This beverage is rich in bioactive compounds, such as polyphenols and dietary fiber, which will bring health benefits when consumed.

Research on pear residue dietary fiber and Monascus pigments extracted through liquid fermentation.

Pear residue, a byproduct of pear juice extraction, is rich in soluble sugar, vitamins, minerals, and cellulose. This study utilized Monascus anka in liquid fermentation to extract dietary fiber (DF) from pear residue, and the structural and functional characteristics of the DF were analyzed. Soluble DF (SDF) content was increased from 7.9/100 g to 12.6 g/100 g, with a reduction of average particle size from 532.4 to 383.0 nm by fermenting with M. anka. Scanning electron microscopy and infrared spectroscopic analysis revealed more porous and looser structures in Monascus pear residue DF (MPDF). Water-, oil-holding, and swelling capacities of MPDF were also enhanced. UV-visible spectral analysis showed that the yield of yellow pigment in Monascus pear residue fermentation broth (MPFB) was slightly higher than that in the Monascus blank control fermentation broth. The citrinin content in MPFB and M. anka seed broth was 0.90 and 0.98 ug/mL, respectively. Therefore, liquid fermentation with M. anka improved the structural and functional properties of MPDF, suggesting its potential as a functional ingredient in food.

Assessment and Partial Characterization of Candidate Genes in Dihydrochalcone and Arbutin Biosynthesis in an Apple-Pear Hybrid by De Novo Transcriptome Assembly.

Apples (Malus × domestica Borkh.) and pears (Pyrus communis L.) are valuable crops closely related within the Rosaceae family with reported nutraceutical properties derived from secondary metabolites including phloridzin and arbutin, which are distinctive phenolic metabolites characterizing apples and pears, respectively. Here, we generated a de novo transcriptome assembly of an intergeneric hybrid between apple and pear, accumulating intermediate levels of phloridzin and arbutin. Combining RNA-seq, in silico functional annotation prediction, targeted gene expression analysis, and expression-metabolite correlations, we identified candidate genes for functional characterization, resulting in the identification of active arbutin synthases in the hybrid and parental genotypes. Despite exhibiting an active arbutin synthase in vitro, the natural lack of arbutin in apples is reasoned by the absence of the substrate and broad substrate specificity. Altogether, our study serves as the basis for future assessment of potential physiological roles of identified genes by genome editing of hybrids and pears.

Enhancing the flavour quality of Laiyang pear wine by screening sorbitol-utilizing yeasts and co-fermentation strategies.

This study took a novel approach to address the dual challenges of enhancing the ethanol content and aroma complexity in Laiyang pear wine. It focused on sorbitol as a pivotal element in the strategic selection of yeasts with specific sorbitol-utilization capabilities and their application in co-fermentation strategies. We selected two Saccharomyces cerevisiae strains (coded as Sc1, Sc2), two Metschnikowia pulcherrima (coded as Mp1, Mp2), and one Pichia terricola (coded as Tp) due to their efficacy as starter cultures. Notably, the Sc2 strain, alone or with Mp2, significantly increased the ethanol content (30% and 16%). Mixed Saccharomyces cerevisiae and Pichia terricola fermentation improved the ester profiles and beta-damascenone levels (maximum of 150%), while Metschnikowia pulcherrima addition enriched the phenethyl alcohol content (maximum of 330%), diversifying the aroma. This study investigated the efficacy of strategic yeast selection based on sorbitol utilization and co-fermentation methods in enhancing Laiyang pear wine quality and aroma.

In vitro digestion properties of Laiyang pear residue polysaccharides and it counteracts DSS-induced gut injury in mice via modulating gut inflammation, gut microbiota and intestinal barrier.

The aim of this study was to explore the dynamic changes in the physicochemical properties of Laiyang pear residue polysaccharide (LPP) during in vitro digestion, as well as its protective effect on the intestines. Monosaccharide composition and molecular weight analysis showed that there was no significant change in LPP during the oral digestion stage. However, during the gastric and intestinal digestion stages, the glycosidic bonds of LPP were broken, leading to the dissociation of large molecular aggregates and a significant increase in reducing sugar content (CR) accompanied by a decrease in molecular weight. In addition, LPP exerted the intestinal protective ability via inhibiting gut inflammation, improving intestinal barrier, and regulating intestinal flora in DSS-induced mice. Specifically, LPP mitigated DSS-induced intestinal pathological damage of mice via enhancing intestinal barrier integrity and upregulating expressions of TJ proteins, and suppressed inflammation by inhibiting NF-κB signaling axis. Furthermore, LPP decreased the ratio of Firmicutes/Bacteroidetes, increased the relative abundance of Lactobacillus, and altered the diversity and the composition of gut microbiota in DSS-induced mice. Therefore, LPP had the potential to be a functional food that improved gut microbiota environment to enhance health and prevent diseases, such as a prebiotic.

Nondestructive detection of SSC in multiple pear (Pyrus pyrifolia Nakai) cultivars using Vis-NIR spectroscopy coupled with the Grad-CAM method.

Vis-NIR spectroscopy coupled with chemometric models is frequently used for pear soluble solid content (SSC) prediction. However, the model robustness is challenged by the variations in pear cultivars. This study explored the feasibility of developing universal models for predicting SSC of multiple pear varieties to improve the model's generalizability. The mature fruits of 6 pear cultivars with green skin (Pyrus pyrifolia Nakai cv. 'Cuiyu', 'Sucui No.1' and 'Cuiguan') and brown skin (Pyrus pyrifolia Nakai cv. 'Hosui','Syusui' and 'Wakahikari') were used to establish single-cultivar models and multi-cultivar universal models using convolutional neural network (CNN), partial least square (PLS), and support vector regression (SVR) approaches. Multi-cultivar universal models were built using full spectra and important variables extracted by gradient-weighted class activation mapping (Grad-CAM), respectively. The universal models based on important variables obtained satisfactory performances with RMSEPs of 0.76, 0.59, 0.80, 1.64, 0.98, and 1.03°Brix on 6 cultivars, respectively.

A sensitive fluoroimmunoassay for quantitative detection of imidacloprid based on quantum dot-streptavidin conjugate.

Imidacloprid (IMI), the most commonly used neonicotinoid, is widely present in both the environment and agro-products due to extensive and prolonged application, posing potential risks to ecological security and human health. This study introduced a sensitive and rapid fluorescence-linked immunosorbent assay, employing Quantum Dot-Streptavidin conjugate (QDs-SA-FLISA), for efficient monitoring of IMI residues in agro-products. Under optimized conditions, the QDs-SA-FLISA exhibited a half-maximal inhibition concentration (IC50) of 1.70 ng/mL and a limit of detection (LOD, IC20) of 0.5 ng/mL. Investigation into the sensitivity enhancement effect of the QDs-SA revealed that the sensitivity (IC50) of the QDs-SA-FLISA was 7.3 times higher than that of ELISA. The recoveries and relative standard deviation (RSD) ranged from 81.7 to 118.1 % and 0.5-9.4 %, respectively, for IMI in brown rice, tomato and pear. There was no significant difference in IMI residues obtained between QDs-SA-FLISA and UHPLC-MS/MS. Thus, the QDs-SA-FLISA represents a reliable approach for the quantitative determination of IMI in agro-products.

Combining transfer learning and hyperspectral imaging to identify bruises of pears across different bruise types.

Mechanical bruise is one of the most crucial factors affecting the quality of pears, which has a huge influence on postharvest transportation, storage, and sale of pears. To rapidly detect early bruises of pears across different bruise types, hyperspectral imaging technology coupled with transfer learning methods was performed in this study. Two transfer learning methods, that is, transfer component analysis (TCA) and manifold embedded distribution alignment (MEDA), were applied for two tasks (impact bruise â†’ crush bruise, crush bruise â†’ impact bruise). Supporting vector machine (SVM) was set as a baseline to conduct analysis and comparison of the transferability of the models. The result showed that, for task 1 (impact bruise â†’ crush bruise), MEDA and TCA-SVM model achieved a classification accuracy of 93.33% and 91.11% in target domain, individually. For task 2 (crush bruise â†’impact bruise), MEDA and TCA-SVM model achieved an accuracy of 88.89% and 85.19% in target domain, respectively. Both the two models improved the accuracy compared with SVM models (84.44% for task 1; 77.04% for task 2). Overall, the results indicated that transfer learning approaches could perform pear bruise detection across different bruise types. Hyperspectral imaging in combination with transfer learning methods is a promising possibility for the efficient and cost-saving field detection of fruit bruises among different bruise types. PRACTICAL APPLICATION: The production and export of pears are faced with problems of mechanical damage due to vibration, collision, impact, and other factors, which cause chemical changes in color, odor, and taste. Sometimes the bruise was too slight to be ignored which would infect with other fruits in the future. In this study, we used hyperspectral imaging combined with transfer learning method could detect these slight bruises caused by different factors. Distinguishing different types of damage can provide a reference for quick judgment of the process causing damage and take prompt measures to reduce economic losses.

Preparation of spore-immobilized glutathione reductase and its application in inhibiting browning of pear wine.

BACKGROUND: Browning is the key problem hindering the industrialization of pear wine. The use of high-yield glutathione Saccharomyces cerevisiae in the fermentation of pear wine can inhibit browning. Glutathione reductase (GR) can ensure the reduction of glutathione. Spore immobilization of enzymes is a new technology. It is a new attempt to apply spore-immobilized GR in combination with high-yield glutathione S. cerevisiae to inhibit browning of pear wine. RESULTS: Saccharomyces cerevisiae spore immobilization enzyme technology was used to immobilize GR in the spores of mutant S. cerevisiae dit1∆, osw2∆ and chs3∆ and wild-type S. cerevisiae. The enzyme activity of GR immobilized by chs3∆ spores was the highest of 3.08 U mg-1 min-1. The chs3∆ spore-immobilized GR had certain resistance to ethanol, citric acid, sucrose, glucose and proteinase K. Electron microscopy analysis showed that the spore wall of chs3∆ had moderate size holes, which might be the main reason why it immobilized GR with the highest enzyme activity. And the GR was immobilized between the prespore membrane and mannoprotein layer of the spore wall. When chs3∆ spore-immobilized GR (chs3∆-GR) was added to Dangshan pear wine fermented by high-yield glutathione S. cerevisiae JN32-9, the presence of chs3∆-GR could further protect amino acids, polyphenols and glucose from oxidation, thereby reducing the browning of the pear wine during storage by 47.32%. CONCLUSION: GR immobilized by S. cerevisiae spores was effective in inhibiting the browning of pear wine. The method was simple, green and effective and did not increase the production cost of pear wine. © 2024 Society of Chemical Industry.

Green synthesis of superhydrophilic resin/graphene oxide for efficient analysis of multiple pesticide residues in fruits and vegetables.

The escalating use of pesticides on fruits and vegetables has raised concerns about potential health risks. Therefore, we developed a superhydrophilic resin/graphene oxide (SR/GO) with rich adsorption interactions using an eco-friendly synthetic approach. SR/GO demonstrated excellent hydrophilicity, ensuring optimal contact with aqueous sample matrices. The multiple adsorption interactions, including π-π conjugation, hydrogen bonding, and electrostatic adsorption, facilitated multi-pesticide residue co-extraction. The synthesized SR/GO was applied to a miniaturized centrifugation-accelerated pipette-tip extraction method, coupled with high-performance liquid chromatography. The optimized method exhibited low consumption (15.0 mg adsorbent), and high efficiency, with low detection limits (1.4-2.9 ng g-1) and high recoveries (75.3-113.0%). Water-compatible SR/GO, along with a miniaturized extraction process, showcases a potent analytical approach for pesticide residue analysis in fruits and vegetables. The significance of this method lies in its ability to ensure agricultural and food safety by using a low-cost and efficient multi-pesticide residue analytical strategy.

Evaluating the use of unmanned aerial vehicles for spray applications in mountain Nanguo pear orchards.

BACKGROUND: Nanguo pear is a distinctive pear variety in northeast China, grown mainly in mountainous areas. Due to terrain limitations, ground-based pesticide application equipment is difficult to use. This limitation could be overcome by using unmanned aerial vehicles (UAVs) for pesticide application in Nanguo pear orchards. This study evaluated the spraying performance of two UAVs in the Nanguo pear orchards and compared them with a manually used backpack electric sprayer (BES). The study also analyzed the effect of canopy size on droplet deposition and ground loss, and evaluated two sampling methods, leaf sampling and telescopic rod sampling. RESULTS: Compared to BESs, droplet deposition is lower for UAVs, but the actual pesticide active ingredient deposition is not necessarily lower given the solution concentration. The droplet deposition varies among different UAVs due to structural differences. Under the same UAV operating parameters, droplet deposition on trees with smaller canopy sizes is typically greater than that on trees with larger canopy sizes, and the ground loss was also more severe. Although telescopic rod sampling is a quick and convenient method, it can only reflect the trend of droplet deposition, and the data error is greater compared with leaf sampling. CONCLUSION: UAVs can achieve better droplet deposition in mountainous Nanguo pear orchards and does almost no harm to the operators compared with the BES. However, canopy size needs to be considered to adjust the application volume rate. Telescopic rods can be used for qualitative analyses, but are not recommended for quantitative analyses. © 2024 Society of Chemical Industry.