Evaluation of Polycyclic Aromatic Hydrocarbons (PAHs) in Bamboo Shoots from Soil.

The toxicity, carcinogenicity and persistence of polycyclic aromatic hydrocarbons (PAHs) pose a great threat to the ecological system and human health. The contamination levels, translocation and source analysis of 16 PAHs in bamboo shoot and its planted soil were investigated. The average concentrations of total PAHs were 18.80 ± 1.90 µg/kg and 123.98 ± 113.36 µg/kg in bamboo shoots and soils, respectively. The most abundant PAH was Phenanthrene (PHE), with the detected average concentrations of 5.85 µg/kg in bamboo shoots and 19.28 µg/kg in soils. The highest detected types of PAHs were 3 rings and 4 rings, with the proportions of 80.69% (bamboo shoots) and 35.23% (soils). The transfer factors of PAHs were ranged from 0.011 to 0.895, in which PAHs with 3 rings showed the strongest transfer ability. The combustion of biomass and petroleum might be the main source of PAHs in the planted soils of bamboo shoots.

Characterization of iron walnut in different regions of China based on phytochemical composition.

Little is known about the phytochemical composition of iron walnuts. Differences in the geographical origin of iron walnuts associated with economic benefits should also be examined. In this study, the phytochemical composition (fatty acids, Vitamin E, total polyphenols and flavonoids, amino acids, and minerals) of iron walnuts in China was investigated. The results showed that there were significant differences (p < 0.05) in the phytochemical composition of iron walnut oils and flours from different regions. Positive (r > 0.5, p < 0.05) and negative (r < - 0.5, p < 0.05) correlations were found between amino acids/minerals and amino acids/oleic acid, with the highest correlation coefficient (r = 0.742, p < 0.05) between Cu and tyrosine. In addition, based on the 12 phytochemical fingerprints selected by random forest, a geographical-origin identification model for iron walnuts was established, with a corresponding correct classification rate of 96.6%. The top three phytochemical fingerprints for the geographical-origin identification of iron walnut were microelements, macroelements, and antioxidant composition, with contribution rates of 61.7%, 18.1%, and 9.9%, respectively.

Evaluation of risk levels of trace elements in walnuts from China and their influence factors: Planting area and cultivar.

The potential health risk of trace elements in nut foods has been widely concerned. The accumulations of trace elements by plants in the environment are disturbed by multiple factors. The objective of this work was to investigate the risk levels of trace elements in walnuts and their influence factors (planting area and cultivar). A total of 228 walnut samples were collected from four major walnut producing areas of China. The contents of essential elements for Fe, Cu, Zn, Mo and Se were 35.8, 21.9, 14.8, 0.3 and 0.04 mg/kg, respectively. The contribution of Cu for dietary reference intake was as high as 82.22%. The risk levels of potential toxicological elements and toxic elements within the acceptable limits. Significantly, the hazard quotients (HQs) of Ba and Co were up to 26.14% and 25.31%, respectively. The effect of planting area on trace elements was determined from the aspects of regional distribution and urbanization. Significant differences of essential elements were found between northeast and northwest areas. The urbanization directly influenced toxic elements, which could cause variation up to 85.0% (Pb) and 42.9% (As). Finally, cultivar effect was confirmed that all walnut cultivars were divided into four categories with different trace element characteristics.

Risk assessment and prediction for toxic heavy metals in chestnut and growth soil from China.

BACKGROUND: Toxic heavy metals (THMs) cause severe environmental hazards and threaten human health through various consumption of food stuff. However, little is known of THMs in chestnuts. In this study, the risk assessment and prediction of THMs [lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd) and mercury (Hg)] in chestnuts and growth soils from China were investigated. RESULTS: The main detected THMs in chestnuts and growth soils were As and Cd. The total pollution levels of the five THMs (Nemerow pollution indexes, NPIs) were 0.062 and 1.06, respectively. The dietary risks for children were higher than those of adults, especially short-term non-carcinogenic risk. The main combined risks from the relationships between THMs were Pb-Cr (r = 0.85, P < 0.01) in chestnuts and Pb-As (r = 0.59, P < 0.01) in growth soils. The risk source was found to be the uptake effect of THMs from soil to chestnut, with the highest bioaccumulation factors (BCFs) of Cd (0.254). Several comprehensive risk models were established with the highest coefficient of determination (R2 ) of 0.79. In addition, the main contribution rates of different soil parameters to comprehensive risk of THMs uptake were 49.8% (Cd), 23.4% (pH), 13.8% (Cr) and 13.0% (organic carbon). CONCLUSION: The total pollution levels of THMs fell outside of the safety domain in growth soils. Furthermore, more attention needs to be paid to Cd pollution owing to its low environment background value and high accumulation ability. Three main soil parameters (Cr content, pH, organic carbon) played important roles in the formations and accumulations of THMs in chestnuts. © 2019 Society of Chemical Industry.

Environmental behaviors of phoxim with two formulations in bamboo forest under soil surface mulching.

Phoxim (emulsifiable concentrate (EC) and granules (G)) has been widely used in bamboo forests. The persistence and magnitude of phoxim residues in the crop and soil must be investigated to ensure human and environmental safety. The environmental behaviors of the two formulations were investigated in a bamboo forest under soil surface mulching conditions (CP) and non-covered cultivation conditions (NCP). The half-lives of phoxim in soil under the two conditions in soil were 4.1-6.2days (EC) and 31.5-49.5days (G), respectively. Phoxim in EC could be leached from the topsoil into the subsoil. A minimized leaching effect was observed for G under NCP. Inversely, an enhanced leaching effect was observed for G under CP. The G formulation resulted in more parent compound (in bamboo shoots) and metabolite (in soil) residues of phoxim than in the case of EC, especially under CP conditions. In addition, the intensity and duration of the formulation effect on soil pH adjustment from G were more obvious than that from EC. Results showed that the environmental behaviors (distribution, degradation, residue) of phoxim in the bamboo forest were significantly influenced by the type of formulation. The prolongation effect from phoxim G might cause persistence and long-term environmental risk. However, bamboo shoot consumption could be considered relatively safe after applying the recommended dose of the two phoxim formulations.

External browning mechanism in walnut kernel pellicles under different drying conditions based on the combination of widely-targeted and anthocyanin-targeted metabolomics.

There has been limited research on external browning (EB) of walnut. This work discovered 1888 metabolites and 34 anthocyanins in walnut pellicles (WPs) after three drying methods using widely-targeted and anthocyanin-targeted metabolomics. Based on OPLS-DA and correlation analysis, 64 temperature-responsive metabolites (TRMs; 13 anthocyanins and 51 flavonoids) were identified as critical components in relation to EB. Notably, 14 flavonoids exhibited a strong positive correlation (r > 0.9) with the browning index (BI), with upregulation of >60% after browning. Most of the identified anthocyanins were negatively linked with BI because of degradation (>45%), with correlation coefficients ranging from 0.75 to 0.97. Furthermore, anthocyanidin reductase and laccase were the two key enzymes involved in the EB of WPs, with their activities increasing by 10.57-fold and 1.32-fold, respectively, with increasing drying temperature. A metabolic pathway network of the TRM was built to provide insights into the potential mechanisms underlying EB in WPs.

Maturation-induced changes in phenolic forms and their antioxidant activities of walnuts: A dual view from kernel and pellicle.

The phenolic profiles and antioxidant activities during walnut maturation are not well understood. This study used UPLC-MS/MS to evaluate phenolic content in walnuts, including free, esterified, and bound forms, at different maturation stages. Findings showed that free phenolics were predominant, comprising 44.57 % in kernels and 56.54 % in pellicles. In vitro assays showed antioxidant capacity decreased with maturation, with IC50 values of 0.87-84.43 µg/mL in pellicles and 48.51-712.30 µg/mL in kernels. Most monomeric phenols decreased in concentration as the fruit ripened. OPLS-DA identified 5 and 8 maturity-sensitive phenolics (MSPs) in kernels and pellicles, respectively, with fold changes from 2.32 to 1664.72. Pearson correlation analysis showed a significant correlation between MSPs and antioxidant activity (r > 0.75, p < 0.05). Bioinformatics analysis elucidated three key metabolic pathways involved in these changes. This research provides insights into walnut phenolic composition, important for optimizing harvest practices and enhancing nutritional value.

Unraveling the metabolic profile regulation of camellia oilseeds under insect and heat stress: Insights into functional effects and mechanistic basis.

There is very little information on the impacts of pre/post-harvest stresses on oilseeds. Individual and combined insect (pre-harvest) and heat stress (post-harvest) impacts on the metabolic profile of camellia oilseeds (COs) were investigated using a combination of widely-targeted metabolomics and network pharmacology. A total of 1875 metabolites were identified. In response to individual and combined stresses, 169 (insect),149 (heat), and 21 (insect + heat) metabolites were screened as differential metabolic markers (DEMs), Terpenoids, phenolic acids, and flavonoids are the most impacted metabolite species, accounting for almost 49% of total DEMs. Then network pharmacological analysis identifies 98 key active ingredients (AIs) in CO. A single stress may induce CO to impede cardiovascular system function, but the combined stress induced AI-promoting effects of CO in the urinary system. The individual and combined perturbed biological mechanisms were related to the flavonoid biosynthesis and the biosynthesis of various plant secondary metabolites pathway, respectively.

Simultaneous determination of 15 multiresidue organophosphorous pesticides in camellia oil by MSPD-GC-MS.

A one step method based on matrix solid-phase dispersion for simultaneous determination of 15 organophosphorous pesticide residues in camellia oil was developed. The sample preparation could finish in 5 min without extraction procedure, and then analyzed by gas chromatograph-mass spectrometer. Average recoveries ranged between 73.2 % and 108.6 %, with relative standard deviation values (intra-day and inter-day) lower than 16 % at two concentration levels. The method limit of detection was 5 ng/g, which could meet the regulatory maximum residue limits for the pesticides.

Multiresidue determination of organophorous pesticides in camellia oil by matrix solid-phase dispersion followed by GC-FPD.

A novel analytical approach has been developed and evaluated for the quantitative analysis of 15 organophorous pesticides residues in camellia oils. The proposed methodology is based on acetonitrile/water (3:1, V/V) extraction, followed by matrix solid-phase dispersion, using aminopropyl as dispersant material. Then gas chromatography-flame photometric detection was applied for the pesticide residue analysis. The optimal sorbent quantity was studied. The results demonstrated that the method achieved acceptable quantitative recoveries of 71.5%-104.2% with relative standard deviations <19%, and the method limit of detection at or below the regulatory maximum residue limits for the pesticides were achieved.

Heavy metals in bamboo shoots from Southeastern China and risk assessment.

Bamboo shoot is an indispensable vegetable in Southeastern China, so a survey of heavy metals in bamboo shoots is a relevant topic of interest. The present study sought to analyse the content of seven heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) in six bamboo shoot species from Southeastern China. Percentages of 3.8% (Cd) and 8.9% (Pb) of the samples exceeded the maximum limits as established by the Chinese legislation. Further health risk assessment exhibited that the Cd intake contribution of these samples could not be negligible. The hazard index (HI) at average exposure was less than one. The average HI values in moso bamboo shoot were significantly higher than those of other bamboo shoot species. Overall, the results indicated that the intake of bamboo shoots is safe for consumers in Southeastern China.

Uptake effects of toxic heavy metals from growth soils into jujube and persimmon of China.

Compared with other agricultural plants, information about uptake effects of toxic heavy metals from growth soils into persimmon and jujube are scarce. In this study, the single and comprehensive uptake effects of five toxic heavy metals (Pb, As, Cd, Cr, and Hg) between the two fruits and their growth soils were investigated. The results showed that the average concentrations of heavy metals in the two fruits were found to be 30 (Pb), 6.6 (As), 2.3 (Cd), 38 (Cr), and 0.33 (Hg) µg/kg, respectively. The average concentrations of heavy metals in their growth soils were 26.31 (Pb), 9.63 (As), 0.12 (Cd), 57.6 (Cr), and 0.049 (Hg) mg/kg, respectively. An uptake effect was observed for the two fruits. The values of Nemerow pollution index (NPI) in the two fruits and their growth soils were 0.10 and 0.55, respectively. The average bioconcentration factor (BCF) values of Pb, As, Cd, Cr, and Hg in the two fruits were 0.0012, 0.00075, 0.021, 0.00077, and 0.012, respectively. Based on the residue levels of toxic heavy metals in the growth soils and soil parameters, the prediction models for NPI and BCF were established, with the adjusted regression coefficients of 0.65 (NPI) and 0.81 (BCF). The contribution rates of different soil parameters to NPI were 21.7% (OC), 16.1% (Pb), 17.1% (Cr), 19.8% (Cd), and 25.4% (As), respectively. The contribution rates of different soil parameters to BCF were 10.2% (OC), 9.4% (Cr), and 80.4% (Cd), respectively.

Distribution, relationship, and risk assessment of toxic heavy metals in walnuts and growth soil.

Walnut is one of the most popular nuts worldwide and contains various mineral nutrients. Little is known, however, about the relationship between toxic heavy metals in walnuts and growth soil. In this study, we investigated the distribution, relationship, and risk assessment of five toxic heavy metals-lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd), and mercury (Hg)-in walnuts and growth soil in the main production areas of China. The results showed that the main heavy metal pollution in walnut and soil was Pb and Cd. Regionally, positive relationships existed between heavy metals and the pH and organic matter of soil. In addition, we observed a notable uptake effect between walnut and growth soil. In this study, we found a significant correlation (r = 0.786, P < 0.05) between the bioconcentration factors and the longitude of the sampling areas. The risks (total hazard quotients) of five heavy metals toward children and adults by dietary walnut consumption were 46.8 and 56.2%, respectively. The ability to identify toxic heavy metal pollution in walnuts and growth soil could be helpful to screen suitable planting sites to prevent and control heavy metal pollution and improve the quality and safety of walnut.

Determination of benzo[a]pyrene in camellia oil via vortex-assisted extraction using the UPLC-FLD method.

In this paper, vortex-assisted extraction using the ultraperformance liquid chromatography analysis method was performed to determine benzo[a]pyrene in camellia oil. Optimum results were obtained when 0.5 g of oil sample was used followed by vortex-assisted extraction for 10 min with 25 mL of acetonitrile. Chromatographic separation was performed on an Agilent ZORBAX Eclipse Plus C18 column (2.1mm×100mm, particle size 1.8 µm). The optimum mobile phase comprised 70% acetone and 30% water. The detection limit of benzo[a]pyrene was 0.2 µg/kg. The recoveries were in the range of 81.0-97.0%. The proposed method was simple and fast, and it provided high throughput in the determination of benzo[a]pyrene in an oil matrix sample.

Pesticide residues in nut-planted soils of China and their relationship between nut/soil.

Twenty-nine pesticide residues in nut-planted soils from China were investigated. One organophosphate (chlorpyrifos) was detected in 5.3% soils, and the residue levels of 7.2 µg/kg to 77.2 µg/kg. The concentrations of six organochlorines (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) detected in 78.9% soils were 0.6 µg/kg to 90.1 µg/kg. The residue levels of six pyrethroids (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) detected in 65.8% soils were 1.5 µg/kg to 884.3 µg/kg. Triadimefon and buprofezin were found in 71.1% and 52.6% samples, respectively, with the corresponding concentrations of 9.8 µg/kg to 193.7 µg/kg and 87.9 µg/kg to 807.4 µg/kg. The multiple residues were found in 76.3% soils. A significant correlation between pesticide residues in nuts and soils was observed, with the correlation coefficient (r) 0.83 (P < 0.001). In addition, the bioconcentration factor (BCF) values for the explanation of pesticides from soils into nuts were ranged from 0.8 to 16.5. The results showed that some pesticides could accumulate in nut by the uptake effect from soil.

[Determination of 18 polychlorinated biphenyls in camellia seeds by multiple vortex and gas chromatography-triple quadrupole mass spectrometry].

A method based on the cleaning effects of different sorbents and gas chromatography-triple quadrupole mass spectrometry (GC-QQQ-MS/MS) was developed for the determination of 18 polychlorinated biphenyls (PCBs) in camellia seeds. The camellia seeds were extracted with acetonitrile, salted out with sodium chloride, then cleaned-up by QuEChERS with anhydrous MgSO4, C18, primary secondary amine (PSA), and multi walled carbon nanotubes (NANO) using multiple vortex after the centrifugal separation, and finally analyzed by GC-QQQ-MS/MS in multiple reaction monitoring mode via positive electrospray ionization. All the 18 PCBs could be completely separated with an excellent linear relationship. The limits of detection for the 18 PCBs were 5 µg/kg. For all the samples, the mean spiked recoveries was 109.2% with relative standard deviations (RSDs) of 2.9%-6.2% (n=3). The extraction, purification and analytical methods were developed and assessed. The method was successfully applied to the 48 samples from three main producing provinces of camellia seeds. All the 18 PCBs were not detected from the 48 samples.

Toxic and essential elements in five tree nuts from Hangzhou market, China.

In this study, a total of 35 tree nut samples of walnut, pecan, pine seed, hickory nut and torreya were obtained from 5 farm product markets in Hangzhou, China, and investigated for essential (Cr, Mn, Fe, Mo, Cu, Zn, Se and Sr) and toxic (Al, As, Cd and Pb) elements by inductively coupled plasma-mass spectroscopy. Mean elemental concentrations of different tree nuts were in the following ranges: Cr 0.26-0.78 mg kg-1, Mn 42.1-174 mg kg-1, Fe 33.7-43.9 mg kg-1, Mo 0.11-0.48 mg kg-1, Cu 10.3-17.6 mg kg-1, Zn 21.6-56.1 mg kg-1, Se 0.015-0.051 mg kg-1, Al 1.44-37.6 mg kg-1, As 0.0062-0.047 mg kg-1, Cd 0.016-0.18 mg kg-1 and Pb 0.0069-0.029 mg kg-1. The estimated provisional tolerable daily intake of Al, As, Cd and Pb was much lower than the provisional tolerable daily intake.

Residue levels and risk assessment of pesticides in nuts of China.

The pesticide residue levels of three nuts (chestnut, walnut, pinenut) collected from seven main producing areas of China were investigated. Twenty-nine pesticides, including organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and two fungicides (triadimefon and buprofezin) were analyzed by gas chromatography (GC). Four OPs (acephate, dimethoate, chlorpyrifos and parathion-methyl) were found in 11.4% samples, with the concentrations of 19.0 µg kg(-1) to 74.0 µg kg(-1). Six OCs (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) were found in 18.2% samples, with the concentrations of 2.0 µg kg(-1) to 65.7 µg kg(-1). Among OCs, p,p-DDE and α-HCH were the dominant isomer for DDT and HCH. Five PYs (fenpropathrin, fenvalerate, cypermethrin, bifenthrin and cyhalothrin) were found in 15.9% samples, with the concentrations of 2.5 µg kg(-1) to 433.0 µg kg(-1). Fenpropathrin was the most frequently detected pesticide. In addition, triadimefon and buprofezin were detected only in two samples. For the tested nuts, 25.0% samples with multiple residues (containing more than two pesticides) were noted, even up to 9.1% samples with five pesticide residues. The residue of 15.9% samples was higher than the maximum residue limits (MRLs) of China. The short-term risks for the tested nuts were below 1.2%, and the highest long-term risk was 12.58%. The cumulative risk (cHI) for the tested pesticides were 8.43% (OPs), 0.42% (OCs), 12.82% (PYs) and 0.15% (fungicides), respectively. The total cHI was 21.82%. There was no significant health risk for consumers via nuts consumption.

Pesticides in persimmons, jujubes and soil from China: Residue levels, risk assessment and relationship between fruits and soils.

Extreme and uncontrolled usage of pesticides produces a number of problems for vegetation and human health. In this study, the existence of organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and fungicides (FUs) were investigated in persimmons/jujubes and their planted soils, which were collected from China. One OP (dimethoate), three OCs (DDT, quintozene and aldrin), six PYs (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) and two FUs (triadimefon and buprofezin) were found in 36.4% of persimmons and 70.8% of jujubes, with concentrations from 1.0 µg/kg to 2945.0 µg/kg. The most frequently detected pesticides in the two fruits were fenpropathrin in persimmons and cypermethrin in jujubes, with the detection frequencies of 30.0% and 22.7%, respectively. The residues of 4.5% (persimmon) and 25.0% (jujube) of samples were higher than the maximum residue limits (MRLs) of China. Compared with the fruits, more types of pesticides and higher residues were observed in their planted soils. The most frequently detected pesticides were HCH in persimmon soil and DDT in jujube soil, with the detection frequencies of 10.9% and 12.7%, respectively. For the tested samples, 39.1% of fruit samples and 63.0% of soil samples with multiple residues (containing more than two pesticides) were noted, even up to 8 residues in fruits and 14 residues in soils. Except for cyhalothrin, the other short-term risks for the tested pesticides in the fruits were below 10%, and the highest long-term risk was 14.13% for aldrin and dieldrin. There was no significant health risk for consumers via consumption of the two fruits.

Influence of different formulations on chlorpyrifos behavior and risk assessment in bamboo forest of China.

The effects of two formulations (emulsifiable concentrate (EC) and granule (G)) on the distribution, degradation, sorption, and residue risk of chlorpyrifos (CHP) were investigated in two producing areas of bamboo shoot. The results showed that CHP was mainly distributed in the topsoil (0-5 cm, P < 0.05), with the proportion of CHP in the total quantity ranging from 76.0 to 100.0 % (G) and 12.0 to 98.1 % (EC), respectively. The degradation of CHP-EC in soils (half-life 27.7-36.4 days) was faster than that of CHP-G in soils (half life above 120-150 days). The main metabolite of CHP, 3,5,6-trichloro-2-pyridinol (TCP), was found in soil samples. CHP showed good sorption ability in the two tested soils, with the sorption coefficient (KF) of 43.76 and 94.43 mg/kg. The terminal residues of CHP in bamboo shoots were in the range of 15.2-75.6 (G) and 10.4-35.7 µg/kg (EC), respectively. The soil type had a notable effect on the CHP behaviors in soil (P < 0.05, especially for CHP-G), but it did not affect the metabolite of CHP. Although some positive bamboo shoot samples (CHP residue exceeding maximum residue limits) were found, the hazard quotients did not exceed 7 %, which meant there was a negligible risk associated with the exposure to CHP via the consumption of bamboo shoots.