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1.
BMC Plant Biol ; 21(1): 166, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33823793

RESUMO

BACKGROUND: Pollination accelerate sepal development that enhances plant fitness by protecting seeds in female spinach. This response requires pollination signals that result in the remodeling within the sepal cells for retention and development, but the regulatory mechanism for this response is still unclear. To investigate the early pollination-induced metabolic changes in sepal, we utilize the high-throughput RNA-seq approach. RESULTS: Spinach variety 'Cornel 9' was used for differentially expressed gene analysis followed by experiments of auxin analog and auxin inhibitor treatments. We first compared the candidate transcripts expressed differentially at different time points (12H, 48H, and 96H) after pollination and detected significant difference in Trp-dependent auxin biosynthesis and auxin modulation and transduction process. Furthermore, several auxin regulatory pathways i.e. cell division, cell wall expansion, and biogenesis were activated from pollination to early developmental symptoms in sepals following pollination. To further confirm the role auxin genes play in the sepal development, auxin analog (2, 4-D; IAA) and auxin transport inhibitor (NPA) with different concentrations gradient were sprayed to the spinach unpollinated and pollinated flowers, respectively. NPA treatment resulted in auxin transport weakening that led to inhibition of sepal development at concentration 0.1 and 1 mM after pollination. 2, 4-D and IAA treatment to unpollinated flowers resulted in sepal development at lower concentration but wilting at higher concentration. CONCLUSION: We hypothesized that sepal retention and development might have associated with auxin homeostasis that regulates the sepal size by modulating associated pathways. These findings advanced the understanding of this unusual phenomenon of sepal growth instead of abscission after pollination in spinach.


Assuntos
Flores/crescimento & desenvolvimento , Expressão Gênica/fisiologia , Ácidos Indolacéticos/administração & dosagem , Polinização , Spinacia oleracea/metabolismo , Flores/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , RNA-Seq , Spinacia oleracea/genética , Spinacia oleracea/crescimento & desenvolvimento
2.
Sci Total Environ ; 772: 145523, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578170

RESUMO

Perfluoroalkylated acids (PFAAs) are ubiquitous xenobiotic substances characterized by high persistence, bioaccumulation potential and toxicity, which have attracted global attention due to their widespread presence in both water and biota. In this study, the main objective was to assess PFAAs uptake and accumulation in lettuce (Lactuca sativa L.) and spinach (Spinacia oleracea L.) when fed with reclaimed wastewaters that are usually discharged onto a surface water body. Lettuce and spinach were grown in hydroponic solutions, exposed to two different municipal wastewater treatment plant (WWTP) effluents and compared with a spiked-PFAAs aqueous solution (nominal concentration of 500 ng L-1 for each perfluoroalkyl acid). Eleven perfluoroalkyl carboxylic acids and three perfluoroalkyl sulfonic acids were determined in the hydroponic solution, as well as quantified at the end of the growing cycle in crop roots and shoots. Water and dry plant biomass extracts were analyzed by liquid chromatography-electrospray ionization tandem spectrometry LC-MS/MS technique. The bioconcentration factor of roots (RCF), shoots (LCF), and the root-shoot translocation factor (TF) were quantified. In general, results showed that PFAAs in crop tissues increased at increasing PFAAs water values. Moreover some PFAAs concentrations (especially PFBA, PFBS, PFHxA, PFHpA, PFHxS) were different in both shoots and roots of lettuce and spinach, regardless of the type of water. The long C-chain PFAAs (≥9) were always below the detection threshold in WWTPs effluents. However, when PFAAs were detected, similar bioconcentration parameters were found between crops regardless the type of water. A sigmoidal RCF pattern was found as the perfluorinated chain length increased, plus a linear TF decrease. Comparing bioconcentration factor results with findings of previous studies, lettuce RCF value of PFCAs with perfluorinated chain length ≤ 9 and PFSAs was up to 10 times greater.


Assuntos
Fluorcarbonetos , Poluentes Químicos da Água , Cromatografia Líquida , Fluorcarbonetos/análise , Alface , Spinacia oleracea , Espectrometria de Massas em Tandem , Águas Residuárias , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
3.
Int J Food Microbiol ; 343: 109086, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33631605

RESUMO

The importance of leaf integrity, i.e. the effects of bruising (mechanical damage), and sanitisation with peroxyacetic acid (PAA) on bacterial communities of ready-to-eat baby spinach remains unclear. Two shelf-life studies were conducted at 4 °C to investigate the effect of bruising and sanitisation on the growth of spoilage microorganisms. In the first experiment, both bruising treatments (100% and 40% of leaves) halved shelf life to 12 d, whereas intact leaves had a shelf-life of 23 d. Bruising had no influence on bacterial diversity during shelf-life, though some differences in the relative abundance of minor genera were observed. Pseudomonas and Pantoea were the most dominant bacterial genera, regardless of bruising treatment. High throughput amplicon sequencing also identified other spoilage bacteria including Chryseobacterium, Stenotrophomonas, Bacillus, Sphingobacterium, Erwinia and Flavobacterium. In the second experiment, washing of intact baby spinach with a sanitiser (80 mg/L: PAA) reduced microbial load as determined by aerobic plate count but did not immediately affect the presence/relative abundance of most of the genera of spoilage bacteria observed. During shelf-life, the bacterial diversity of sanitised leaves was significantly lower than on water-washed leaves. Although sanitisation resulted in a higher initial log reduction in microbial load compared to control (portable tap water), sanitisation did not extend the shelf life of baby spinach (23 d). Sanitised spinach had reduced bacterial diversity however, by the end of shelf life, both sanitised and water-washed spinach was dominated by Pseudomonas and Pantoea spoilage bacteria. This study demonstrated for the first time that the shorter shelf life of bruised leaves was related to faster microbial growth rather than changes in bacterial diversity or community composition.


Assuntos
Desinfetantes/farmacologia , Armazenamento de Alimentos/métodos , Microbiota/efeitos dos fármacos , Ácido Peracético/farmacologia , Spinacia oleracea/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Folhas de Planta/microbiologia , Água/farmacologia
4.
Nutrients ; 13(2)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540724

RESUMO

Juicing vegetables is thought to be an anticancer treatment. Support exists for a rank order of anticancer greens (kale > dandelion > lettuce > spinach) based on degrees of bioavailability of different phytochemicals, also offset by some noxious molecules (i.e., calcium-oxalate). We developed a new in vitro transepithelial anti-neuroblastoma model system. The juices were diluted as predicted once in the small intestine. They were applied to apical Caco-2Bbe1 cells atop dividing SH-SY5Y neuroblastoma cells, and changes in transepithelial electrical resistance (TEER) and cell growth were considered with juice spectroscopies. Studied first in monoculture, kale and dandelion were the most cytostatic juices on SH-SY5Ys, lettuce showed no effect, and high (4.2%) spinach was cytotoxic. In co-culture, high (4.2%) kale was quickest (three days) to inhibit neuroblastoma growth. By five days, dandelion and kale were equally robust. Lettuce showed small anti-proliferative effects at five days and spinach remained cytotoxic. Spinach's cytotoxicity corresponded with major infrared bands indicative of oxalate. Kale juice uniquely induced reactive oxygen species and S-phase cell cycle arrest in SH-SY5Y. The superiority of kale and dandelion was also apparent on the epithelium, because raising TEER levels is considered healthy. Kale's unique features corresponded with a major fluorescent peak that co-eluted with kaempferol during high performance liquid chromatography. Because the anticancer rank order was upheld, the model appears validated for screening anticancer juices.


Assuntos
Brassica/química , Técnicas de Cocultura , Neuroblastoma/tratamento farmacológico , Compostos Fitoquímicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Disponibilidade Biológica , Células CACO-2 , Linhagem Celular Tumoral , Impedância Elétrica , Epitélio/efeitos dos fármacos , Epitélio/fisiopatologia , Sucos de Frutas e Vegetais , Humanos , Spinacia oleracea/química , Taraxacum/química
5.
Food Chem ; 347: 129020, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33482490

RESUMO

Datura species are well known because of their high concentration of tropane alkaloids, which has led to poisoning episodes when Datura is accidentally mixed with edible crops. Therefore, the European Union has set a maximum level in cereal-based infant food products of 1 µg kg-1 for atropine and scopolamine. However, the occurrence of these compounds in other commodities has become a global concern. Spinach and derived products can be contaminated with Datura innoxia leaves. In this study, we tested frozen spinachs and spinach-based infant food products. The determination was carried out by UHPLC-MS/MS after applying the QuEChERS method as sample treatment. The LOQs were below 0.016 µg kg-1, achieving satisfactory results in terms of precision, accuracy, and matrix effects. The obtained results (ranging between 0.02 and 8.19 µg kg-1) were close to the maximum level set by the European Union for 24% of the samples tested.


Assuntos
Atropina/análise , Cromatografia Líquida de Alta Pressão/métodos , Datura/química , Análise de Alimentos , Escopolamina/análise , Espectrometria de Massas em Tandem/métodos , Spinacia oleracea
6.
Bull Environ Contam Toxicol ; 106(3): 536-544, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33506325

RESUMO

An experiment was conducted to study the effects of co-composted products of municipal solid waste (MSW) and pigeon pea biochar (PPB) on heavy metal mobility in soil and its uptake by spinach. Application of municipal solid waste biochar co-compost (MSWBC) significantly (p ≤ 0.05) reduced the heavy metal content in spinach leaves and roots compared to municipal solid waste compost (MSWC) amended soil. The percent decrease in spinach leaf following the application of MSWBC-10% PPB compared to MSWC was 20.62%, 28.95%, 36.02%, 41.88%, 41.50%, and 41.23% for Cu, Cd, Pb, Cr, Ni, and Zn, respectively. The dry matter yield of spinach and soil organic carbon (SOC) content in soil amended with MSWBC-10% PPB was significantly increased by 32.75% and 47.73%; and 17.62% and 27.45% relative to control and MSWC amended soil. The study concludes that co-composted product, MSWBC, stabilized heavy metals in MSW, reduced their uptake by spinach and thus making it a viable option for safe disposal of MSW.


Assuntos
Compostagem , Metais Pesados , Poluentes do Solo , Animais , Carbono , Carvão Vegetal , Columbidae , Metais Pesados/análise , Ervilhas , Folhas de Planta/química , Solo , Poluentes do Solo/análise , Resíduos Sólidos/análise , Spinacia oleracea , Verduras
7.
Food Chem ; 347: 129003, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33513447

RESUMO

Traditional functional ingredients, such as conventional emulsifiers (surfactants, animal-derived proteins), and synthetic antioxidants may become obsolete in the development of clean-label, plant-based, sustainable food emulsions. Previously, we showed that tailor-made antioxidant-loaded particles can yield both physically and oxidatively stable emulsions, and we expected that natural particles with related properties could also show these beneficial effects. Here, we investigated Pickering emulsions prepared with natural plant particulate materials. Particles that showed weak aggregation in acidic aqueous media, indicating a relatively hydrophobic surface, were able to physically stabilize oil-in-water emulsions, through either Pickering stabilization (powders of matcha tea, spinach leaves, and spirulina cake), or an increase in viscosity (pineapple fibers). Matcha tea and spinach leaf particle-stabilized emulsions were highly stable to lipid oxidation, as compared to emulsions stabilized by conventional emulsifiers. Taking this dual particle functionality as a starting point for emulsion design is, in our view, essential to achieve clean-label food emulsions.


Assuntos
Emulsões/química , Peroxidação de Lipídeos , Lipídeos/química , Conservação de Alimentos , Óleos/química , Tamanho da Partícula , Folhas de Planta/química , Folhas de Planta/metabolismo , Pós/química , Spinacia oleracea/química , Spinacia oleracea/metabolismo , Chá/química , Chá/metabolismo , Viscosidade , Água/química
8.
Ecotoxicol Environ Saf ; 208: 111723, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396054

RESUMO

Combining biochar (BR) with other immobilizing amendments has additive effects on Pb immobilization and been recognized to be effective for the restoration of Pb polluted soils. However, the impacts of different proportions between BR and a highly efficient Pb immobilizing agent called "magnesium potassium phosphate cement (MC)" have never been earlier investigated. This work aimed to investigate the consequences of BR and MC alone and their mixtures of 25:75, 50:50, and 75:25 ratios on Pb bioavailability, Pb immobilization index (Pb-IMMi), and enzymatic activities in Pb polluted soil. Furthermore, amendments effects on Pb distribution in spinach, growth, antioxidant capacity, biochemical, and nutritional spectrum were also investigated. We found that MC alone performed well to immobilize Pb in soil and reducing its distribution in shoots, but was less efficient to improve soil enzymatic activities and plant attributes. Conversely, the application of BR alone stimulated soil enzymatic activities, plant growth, and quality but was less effective to immobilize Pb in soil and reducing shoot Pb concentrations. The combinations of BR and MC of various ratios showed variable results. Interestingly, the most promising outcomes were obtained with BR50%+MC50% treatment which resulted in enhanced Pb-IMMi (73%), activities of soil enzymes, plant growth and quality, and antioxidant capacity, compared to control. Likewise, significant reductions in Pb concentrations in shoots (85%), roots (78%), extractable Pb (73%) were also obtained with BR50%+MC50% treatment, compared to control. Such outcomes point towards a cost-effective approach for reducing Pb uptake by the plants via using MC and BR at a 50:50 ratio.


Assuntos
Carvão Vegetal/química , Chumbo/farmacocinética , Compostos de Magnésio/química , Fosfatos/química , Compostos de Potássio/química , Poluentes do Solo/farmacocinética , Spinacia oleracea/metabolismo , Disponibilidade Biológica , Materiais de Construção , Recuperação e Remediação Ambiental , Chumbo/análise , Nyctaginaceae/química , Solo/química , Poluentes do Solo/análise , Spinacia oleracea/crescimento & desenvolvimento
9.
Environ Sci Technol ; 55(2): 1167-1177, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33356194

RESUMO

Climate warming is seldom considered in the transformation of pesticides on a plant leaf. This study investigated the effects of photodegradation temperature and spinach growth temperature from 15 to 21 °C on the photodegradation of bifenthrin, cypermethrin, fenvalerate, and deltamethrin on spinach leaves under xenon lamp irradiation in climate incubators. The photodegradation temperature had minor effects on pyrethroid photodegradation. Interestingly, the photodegradation rates decreased with increasing spinach growth temperature. For example, the photodegradation rate constant of bifenthrin on a spinach cultivated at 15 °C (3.73 (±0.59, 95% confidence level) × 10-2 h-1) was 1.9 times higher than that at 21 °C (1.96 (±0.17) × 10-2 h-1). Hydroxyl radicals (·OH) played a dominant role in the photodegradation. We speculate that ·OH originated from the degradation of hydroperoxide that was formed by oxidation of phenolic CH═CH, aliphatic CH3 and aromatic C-O-C, and subsequent hydrogen abstraction. The contents of these functional groups decreased with increasing growth temperature, which resulted in lower photodegradation rates at higher growth temperatures. A possible photodegradation pathway including ester bond cleavage, decyanation, and phenyl group removal was proposed. This work provides new insight into the effects of climate warming on the generation of reactive oxygen species and the transformation of pesticides on a plant leaf.


Assuntos
Inseticidas , Piretrinas , Fotólise , Folhas de Planta , Spinacia oleracea , Temperatura
10.
Int J Food Microbiol ; 339: 109024, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33348312

RESUMO

In-house treatment strategy for fresh produce decontamination has not been emphasized as much as industrial washing. The most common treatment for fresh produce decontamination and cleaning at home and other point-of-use places such as cafeteria is rinsing and/or soaking in a sink. In this study, an appliance utilizing UV and agitated water to decontaminate fresh produce was developed and its effectiveness was investigated in an aim to identify optimum processing parameters. Grape tomato and spinach representing two different surface smoothness were dip-inoculated in a four-strain Salmonella cocktail to reach a final population of 5-8 log CFU/g and air-dried. The produce samples were then washed in 1 gallon tap water under varying conditions, water agitation speed (0-190 RPM), sample size (50-400 g), UV intensity (0-30 mW/cm2) and treatment time (2, 5 and 10 min). In general, increasing the agitation speed and UV intensity enhanced Salmonella inactivation for both grape tomato and spinach. Sample size significantly affected the UV inactivation of Salmonella on grape tomato, but not on spinach. The effect of extending treatment time from 2 to 10 min was insignificant for almost all the UV treatments and the controls. The effect of UV intensity and treatment time on inactivation of Salmonella on spot-inoculated grape tomato and spinach was also determined. The most severe treatment used in this study, 30 mW/cm2 UV for 10 min, resulted in >4 log reductions of Salmonella dip- or spot-inoculated on grape tomato (200 g sample size and 190 RPM agitation speed) and 3.5 log reductions of Salmonella dip- or spot-inoculated on spinach (100 g sample size and 110 RPM agitation speed). We foresee that the UV appliance developed and evaluated in this study could be further fine-tuned and optimized to eventually construct a point-of-use UV appliance that can be used at home, cafeteria, restaurants, and hospitals for fresh produce decontamination and cleaning. The UV appliance could be an inexpensive and effective tool to improve fresh produce safety.


Assuntos
Descontaminação/instrumentação , Descontaminação/métodos , Escherichia coli O157/efeitos da radiação , Microbiologia de Alimentos/instrumentação , Microbiologia de Alimentos/métodos , Raios Ultravioleta , Contagem de Colônia Microbiana , Descontaminação/normas , Lycopersicon esculentum/microbiologia , Salmonella/efeitos da radiação , Spinacia oleracea/microbiologia , Água
11.
Sci Total Environ ; 758: 143883, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33338792

RESUMO

Mercury (Hg) is toxic and can affect human health through soil entering food chain. Spinach absorb easily heavy metals. Corn stover biochar can improve soil structure and physicochemical property. This study wanted to establish a Hg-corn stover biochar-soil-spinach model including 1 control group (without HgCl2 and corn stover biochar) and 24 treatment groups (with HgCl2 or/and corn stover biochar). Hg concentration was 0, 1, 2, 4, and 6 mg kg-1, respectively. Corn stover biochar contents were 0%, 1%, 3%, 5%, and 7% w/w, respectively. The results showed that residual Hg concentrations was the largest and water soluble and exchangeable Hg as well as carbonate bound Hg concentrations were the lowest among five Hg forms. Hg concentrations in four Hg treatment groups were higher than the control group in dose-dependent manner. The deposition of 6 mg kg-1 Hg was the highest. Corn stover biochar decreased Hg migration from soil to leaching solution and spinach, and passivation effect of 7% concentration of corn stover biochar was the best. Besides, corn stover biochar relieved the increase of methyl Hg caused by Hg in soil. Moreover, Hg concentration in roots was the highest and Hg concentration in stems was the lowest in spinach. Furthermore, Hg absorbed by roots was more than the sum of Hg absorbed by stems and leaves. In addition, we also found that the measured soil Hg concentrations were coincided with the predicted soil Hg concentrations under 1, 2, and 4 mg kg-1 Hg concentrations, except 2 mg kg-1 Hg at 7% C. Under 6 mg kg-1 Hg concentration, measured soil Hg concentrations was lower than that of the predicted soil Hg concentrations. Taken together, our findings indicated that corn stover biochar can increase edible safety of spinach by immobilizing Hg in soil and be used as an organic amendment.


Assuntos
Mercúrio , Poluentes do Solo , Carvão Vegetal , Humanos , Mercúrio/análise , Solo , Poluentes do Solo/análise , Spinacia oleracea , Zea mays
12.
Ecotoxicol Environ Saf ; 207: 111230, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898815

RESUMO

Heavy metal like cadmium (Cd) is inessential and highly toxic and is posing serious environmental problems for agriculture worldwide. Presence of Cd gives rise to several physiological and structural disorders that leads to reduction in growth and performance of agricultural plants. Evidence related to subcellular distribution and accumulation of Cd is still enigmatic. Experiment was conducted using hydroponic culture to examine the subcellular accumulation of Cd in Spinacia oleracea L. leaves under Cd stress (50 µM and 100 µM); moreover, the Cd toxicity alleviation using 5 mM silicon (Si) was investigated. Our findings suggest that fresh and dry biomass, shoot and root length, leaf area and length of leaf declined when exposed to Cd stress (50 µM and 100 µM); however, an increase was noticed when Cd treated plants were supplied with Si (5 mM). The content of Ca2+, Mg2+ and Fe2+ in apoplastic washing fluid and symplasm were found to be lower in plants treated with alone Cd, when compared to control. Higher Cd2+:Ca2+, Cd2+:Fe2+ and Cd2+:Mg2+ ratios were detected under cadmium stress in both apoplast and symplast of leaves which were lowered by the addition of 5 mM Si. The novelty of the current study is the detection of increased apoplastic and symplastic Cd concentration in aerial part (i.e., spinach leaves) under alone Cd treatment which was considerably reduced when supplied with Si. Moreover, a noticeable increase in spinach growth and beneficial ionic concentrations suggest that Si can ameliorate the Cd stress in crop plants.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Spinacia oleracea/fisiologia , Agricultura , Biomassa , Folhas de Planta/química , Silício , Poluentes do Solo/análise , Frações Subcelulares/química
13.
Environ Toxicol Pharmacol ; 82: 103563, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33310081

RESUMO

This study determined the heavy metals (HMs) accumulation in different vegetables in different seasons and attributed a serious health hazard to human adults due to the consumption of such vegetables in Jhansi. The total amounts of zinc (Zn), lead (Pb), nickel (Ni), manganese (Mn), copper (Cu), cobalt (Co), and cadmium (Cd) were analysed in 28 composite samples of soil and vegetables (Fenugreek, spinach, eggplant, and chilli) collected from seven agricultural fields. The transfer factor (TF) of HMs from soil to analysed vegetables was calculated, and significant non-carcinogenic health risks due to exposure to analysed heavy metals via consumption of these vegetables were computed. The statistical analysis involving Principal Component Analysis (PCA) and Pearson's correlation matrix suggested that anthropogenic activities were a major source of HMs in the study areas. The target hazard quotient of Cd, Mn, and Pb for fenugreek (2.156, 2.143, and 2.228, respectively) and spinach (3.697, 3.509, 5.539, respectively) exceeded the unity, indicating the high possibilities of non-carcinogenic health risks if regularly consumed by human beings. This study strongly suggests the continuous monitoring of soil, irrigation water, and vegetables to prohibit excessive accumulation in the food chain.


Assuntos
Exposição Dietética/análise , Contaminação de Alimentos/análise , Metais Pesados/análise , Poluentes do Solo/análise , Verduras/química , Adulto , Capsicum , Monitoramento Ambiental , Frutas/química , Humanos , Índia , Folhas de Planta/química , Medição de Risco , Solanum melongena , Spinacia oleracea , Trigonella
14.
Food Microbiol ; 93: 103610, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32912583

RESUMO

Pre-harvest sanitization of irrigation water has potential for reducing pathogen contamination of fresh produce. We compared the sanitizing effects of irrigation water containing neutral electrolyzed oxidizing water (EOW) or sodium hypochlorite (NaClO) on pre-harvest lettuce and baby spinach leaves artificially contaminated with a mixture of Escherichia coli, Salmonella Enteritidis and Listeria innocua (~1 × 108 colony-forming units/mL each resuspended in water containing 100 mg/L dissolved organic carbon, simulating a splash-back scenario from contaminated soil/manure). The microbial load and leaf quality were assessed over 7 days, and post-harvest shelf life evaluated for 10 days. Irrigation with water containing EOW or NaClO at 50 mg/L free chlorine significantly reduced the inoculated bacterial load by ≥ 1.5 log10, whereas tap water irrigation reduced the inoculated bacterial load by an average of 0.5 log10, when compared with untreated leaves. There were no visual effects of EOW or tap water irrigation on baby spinach or lettuce leaf surfaces pre- or post-harvest, whereas there were obvious negative effects of NaClO irrigation on leaf appearance for both plants, including severe necrotic zones and yellowing/browning of leaves. Therefore, EOW could serve as a viable alternative to chemical-based sanitizers for pre-harvest disinfection of minimally processed vegetables.


Assuntos
Descontaminação , Eletrólise , Microbiologia de Alimentos , Folhas de Planta/microbiologia , Água/química , Cloro , Desinfecção , Doenças Transmitidas por Alimentos/microbiologia , Alface/microbiologia , Listeria , Plantas/microbiologia , RNA Ribossômico 16S , Radioisótopos , Hipoclorito de Sódio/química , Spinacia oleracea/microbiologia
15.
Food Microbiol ; 93: 103614, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32912586

RESUMO

There are growing demands globally to use safe, efficacious and environmentally friendly sanitizers for post-harvest treatment of fresh produce to reduce or eliminate spoilage and foodborne pathogens. Here, we compared the efficacy of a pH-neutral electrolyzed oxidizing water (Ecas4 Anolyte; ECAS) with that of an approved peroxyacetic acid-based sanitizer (Ecolab Tsunami® 100) in reducing the total microbial load and inoculated Escherichia coli, Salmonella Enteritidis and Listeria innocua populations on post-harvest baby spinach leaves over 10 days. The impact of both sanitizers on the overall quality of the spinach leaves during storage was also assessed by shelf life and vitamin C content measurements. ECAS at 50 ppm and 85 ppm significantly reduced the bacterial load compared to tap water-treated or untreated (control) leaves, and at similar levels (approx. 10-fold reduction) to those achieved using 50 ppm of Ecolab Tsunami® 100. While there were no obvious deleterious effects of treatment with 50 ppm Tsunami® 100 or ECAS at 50 ppm and 85 ppm on plant leaf appearance, tap water-treated and untreated leaves showed some yellowing, bruising and sliming. Given its safety, efficacy and environmentally-friendly characteristics, ECAS could be a viable alternative to chemical-based sanitizers for post-harvest treatment of fresh produce.


Assuntos
Eletrólise , Contaminação de Alimentos/análise , Folhas de Planta/microbiologia , Spinacia oleracea/microbiologia , Água/química , Bactérias/classificação , Escherichia coli , Microbiologia de Alimentos , Inocuidade dos Alimentos , Armazenamento de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Concentração de Íons de Hidrogênio , Listeria , Oxirredução , Ácido Peracético , Salmonella enteritidis , Temperatura
16.
PLoS One ; 15(12): e0244511, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33373403

RESUMO

In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO2 NPs) in spinach seeds was evaluated on certain growth, physiology and phytotoxicity parameters of the plants. This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.


Assuntos
Fertilizantes , Nanopartículas Metálicas , Prata/farmacologia , Spinacia oleracea/efeitos dos fármacos , Titânio/farmacologia , Germinação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Spinacia oleracea/fisiologia , Suspensões , Testes de Toxicidade
17.
Environ Monit Assess ; 192(11): 709, 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33068180

RESUMO

This investigation aimed to assess the impacts of integrated industrial wastewater (IIW) irrigation on soil properties in the rural area of Haridwar, India, under cultivation of a leafy vegetable, i.e., spinach (Spinacia oleracea). Based on the field data of two cropping years (2016-2017 and 2017-2018), soil characteristics-based prediction models were developed to evaluate heavy metals (HM) uptake by spinach tissues (roots and leaves) using the multivariate regression method. The results showed a significant increase (P < 0.05) in the growth and productivity of spinach plants in IIW irrigated soils as compared to normal borewell water irrigation. For the prediction models, soil parameters including pH, organic matter (%), and HM (mg/Kg) availability showed a significant effect on the HM absorption process by spinach tissues. Besides this, the models were tested using ANOVA (P < 0.001), Student's t test, model efficiency (> 0.50), and coefficient of determination (R2 > 0.81) tools. Furthermore, the prediction models were also verified for their applicability in the 2018-2019 cropping year which gave satisfactory outcomes. The findings of this investigation are important in terms of predicting hazardous HM accumulation in the vegetable crops being grown in wastewater irrigated soils.


Assuntos
Metais Pesados , Poluentes do Solo , Monitoramento Ambiental , Humanos , Índia , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Spinacia oleracea , Águas Residuárias
18.
Ecotoxicol Environ Saf ; 205: 111321, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979800

RESUMO

Soil pollution with cadmium (Cd) has posed a threat to our food safety. And rice consumption is the main source of Cd intake in China. Rice intercropping with water spinach is an efficient way for crop production and phytoremediation in Cd-contaminated soil. However, few people work on the Cd remediation by a combination of the passivation and intercropping. In this study, two passivators (the Si-Ca-Mg ameliorant and the Fe-modified biochar with microbial inoculants) were used in the monoculture and intercropping systems to evaluate the potential of co-effect of passivators and cropping systems on the plant growth and Cd phytoremediation. Results showed that the highest rice biomass and rice yield were presented in the intercropping system with the passivator additions, however, relatively lower biomass was showed in water spinach due to the competition with rice. And more Cd accumulated in water spinach while lower Cd in that of different rice parts. The intercropping system with the addition of the Si-Ca-Mg ameliorant and the microbial Fe-modified biochar significantly reduced the Cd contents in brown rice by 58.86% and 63.83%, while notably enhanced the Cd accumulation of water spinach by 32.0% and 22.0%, compared with the monoculture without passivation, respectively. This probably due to the increased pH, the lowered Cd availability in soil, and the reduced TF and BCF values in rice plants with passivator applications. Collectively, this study indicated that rice-water spinach intercropping, especially with the passivator additions, may function as an effective way for Cd remediation and guarantee rice grain safety.


Assuntos
Biodegradação Ambiental , Cádmio/análise , Oryza/fisiologia , Spinacia oleracea/fisiologia , Biomassa , Carvão Vegetal , China , Grão Comestível/química , Ipomoea , Oryza/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/análise , Água
19.
Chemosphere ; 254: 126794, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957267

RESUMO

Present study carried out pot experiments and evaluated effects of single and binary mixture of nanoparticles (exposed via sludge as soil conditioner) on spinach plant. Exposure of Ag2O nanoparticles (NPs) (1 and 10 mg/kg soil-sludge) did not show significant reduction in plant as compared to control. On the other hand, TiO2 NPs (exposed as single and in binary mixture) resulted in significant increase in root length (29% and 37%) and fresh weight (60% and 48%) at highest exposure concentration. Total chlorophyll content decreased for Ag2O and binary mixture (7% and 4%, respectively) and increased for TiO2 (5%) at 10 mg/kg soil-sludge. The toxic interaction between Ag2O and TiO2 NPs was additive at both exposure concentrations. Ag2O NPs had higher tendency of root surface adsorption than TiO2 NPs. Metal content in spinach leaves at highest exposure concentration was Ag: 2.6 ± 0.55 mg/g plant biomass(for Ag2O NPs) and 1.02 ± 0.32 mg/g plant biomass (for Ag2O + TiO2 NPs) and for Ti: 1.12 ± 0.78 (for TiO2 NPs) mg/g plant biomass and 0.58 ± 0.41 mg/g (for Ag2O + TiO2 NPs). The inadvertent ingestion of NPs- contaminated spinach resulted in projected daily intake (DI) of Ag and Ti for different age-mass classes (child to adult) exceeding the oral reference dose for toxicity during oral ingestion. In conclusion, we report no acute toxicity of single and binary mixture of NPs to spinach but significant accumulation of Ag and Ti metals in spinach leaves. There are high chances that ingestion of spinach grown in such environment might lead to human health risks.


Assuntos
Nanopartículas/toxicidade , Poluentes do Solo/toxicidade , Spinacia oleracea/efeitos dos fármacos , Biomassa , Clorofila , Humanos , Nanopartículas Metálicas/toxicidade , Metais/toxicidade , Nanopartículas/análise , Folhas de Planta/química , Esgotos , Solo , Poluentes do Solo/análise , Spinacia oleracea/crescimento & desenvolvimento , Titânio/farmacologia
20.
J Environ Manage ; 271: 111001, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778287

RESUMO

In topsoils, the activity concentrations of natural radionuclides (hereafter NRs) increase due to the addition of NRs from fertilizers, irrigation water, and air dust pollution. On the other hand, various physical-chemical and environmental processes such as radioactive decay, volatilization, leaching, erosion, and plant uptake were responsible for the decrease of the activity concentrations of NRs in the topsoils. In this study, behaviours of 40K, 210Pb, 226Ra, 238U, and 232Th in topsoils were modelled by the CEMC soil model and the HYDRUS-1D model. An exponential equation was proposed for estimating the accumulation rates of these radionuclides in the topsoils. Long-term accumulation of radionuclides was assessed for water spinach (Ipomoea Aquatica Forssk.) soil (hereafter VES) and rice (Oryza sativa L.) soil (hereafter RIS). We found that the current agricultural practices caused the increase of 40K activity concentration in the water spinach soil, and 40K, 210Pb, 226Ra, and 232Th activity concentrations in the rice soil. The accumulation rates of radionuclides were in the order 238U < 232Th < 226Ra < 210Pb < 40K. 25 years of cultivation with water spinach can increase/decrease + (165 ± 6) Bq of 40K, - (8.2 ± 0.7) Bq of 210Pb, - (4.3 ± 0.2) Bq of 226Ra, - (7 0.3 ± 0.3) Bq of 238U, and - (1.8 ± 0.1) Bq of 232Th in 1 kg soil. For rice cultivation, these values are + (1004 ± 39), + (3.3 ± 0.2), + (3.0 ± 0.2), - (5.1 ± 0.3), (2.2 ± 0.1) Bq kg-1 for 40K, 210Pb, 226Ra, 238U, and 232Th, respectively.


Assuntos
Ipomoea , Oryza , Monitoramento de Radiação , Poluentes Radioativos do Solo/análise , Chumbo , Radioisótopos/análise , Spinacia oleracea , Vietnã , Água
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