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Metals and metalloids (hereafter, metal(loid)s) in plant‐based foods are a source of exposure to humans, but not all metal(loid)‐food interactions are the same. Differences exist between metal(loid)s in terms of their behavior in soils and in how they are taken up by plants and stored in the edible plant tissue/food. Thus, there cannot be one consistent solution to reducing toxic metal(loid)s exposure to humans from foods. In addition, how metal(loid)s are absorbed, distributed, metabolized, and excreted by the human body differs based on both the metal(loid), other elements and nutrients in the food, and the nutritional status of the human. Initiatives like the United States Food and Drug Administration's Closer to Zero initiative to reduce the exposure of young children to the toxic elements cadmium, lead, arsenic, and mercury from foods warrant careful consideration of each metal(loid) and plant interaction. This review explores such plant‐metal(loid) interactions using the example of spinach and the metals cadmium and lead. This review highlights differences in the magnitude of exposure, bioavailability, and the practicality of mitigation strategies while outlining research gaps and future needs. A focus on feasibility and producer needs, informed via stakeholder interviews, emphasizes the need for better analytical testing facilities and grower and consumer education. More research should focus on minimization of chloride inputs for leafy greens to lessen plant‐availability of Cd and the role of oxalate in reducing Cd bioavailability from spinach. These findings are applicable to other leafy greens (e.g., kale, lettuce), but not for other plants or metal(loid)s. Plain Language Summary: Toxic metals like cadmium and lead in foods can be harmful to our health, especially for babies and young children who are more vulnerable due to their smaller size and rapid development. Leafy greens like spinach can absorb these metals from the soil but in different ways. In addition, how and where they accumulate in edible plant tissues also differs. This review uses spinach as an example to compare and contrast how cadmium and lead differ in how they move through soil and accumulate in plant foods. It also discusses practical pre‐ and post‐harvest techniques to lessen human exposure to these metals that can be adopted by producers and consumers. Finally, it highlights future needs and research directions. Key Points: The toxic elements targeted in the Food and Drug Administration Closer to Zero action plan behave differently in soils and in plant uptakeMitigation strategies to reduce exposure to toxic elements must consider the drivers of soil mobility and accumulation into edible tissuesHealth and nutrition factors that affect metal and metalloid bioavailability upon ingestion should also be considered [ABSTRACT FROM AUTHOR]

A review of quantitative risk assessment (QRA) models of Listeria monocytogenes in produce was carried out, with the objective of appraising and contrasting the effectiveness of the control strategies placed along the food chains. Despite nine of the thirteen QRA models recovered being focused on fresh or RTE leafy greens, none of them represented important factors or sources of contamination in the primary production, such as the type of cultivation, water, fertilisers or irrigation method/practices. Cross-contamination at processing and during consumer's handling was modelled using transfer rates, which were shown to moderately drive the final risk of listeriosis, therefore highlighting the importance of accurately representing the transfer coefficient parameters. Many QRA models coincided in the fact that temperature fluctuations at retail or temperature abuse at home were key factors contributing to increasing the risk of listeriosis. In addition to a primary module that could help assess current on-farm practices and potential control measures, future QRA models for minimally processed produce should also contain a refined sanitisation module able to estimate the effectiveness of various sanitisers as a function of type, concentration and exposure time. Finally, L. monocytogenes growth in the products down the supply chain should be estimated by using realistic time–temperature trajectories, and validated microbial kinetic parameters, both of them currently available in the literature. [ABSTRACT FROM AUTHOR]

Climate change and the degradation of ecosystems is an urgent issue to which the agricultural sector contributes through the overuse of productive inputs such as chemical fertilizers. A disproportionate use of nitrogenous fertilizers combined with low efficiency inevitably results in worsening environmental problems (greenhouse gas emissions, soil degradation, water eutrophication, and groundwater pollution). Nevertheless, increasing population growth puts additional pressure on the already struggling agricultural world. Awareness of these problems has pushed the world of research towards the development of more sustainable but equally efficient strategies in terms of production. The use of biostimulant substances and/or micro-organisms promoting yield, resilience to abiotic stresses in plants, and increasing the functional quality of products have been indicated as a valid strategy to improve the sustainability of agricultural practices. In modern horticulture, the use of vegetable–protein hydrolysates (V-PHs) is gaining more and more interest. These biostimulants could influence plants directly by stimulating carbon and nitrogen metabolism and interfering with hormonal activity, but also indirectly as V-PHs could improve nutrient availability in plant growth substrates and increase nutrient uptake and utilization efficiency. By exploiting this aspect, it would be possible to reduce the use of chemical fertilizers without affecting potential yields. After a brief introduction to the issues related to the intensive use of nitrogen fertilizers, this review focuses on the use of V-PHs as a strategy to increase nitrogen use efficiency (NUE). Starting with their heterogeneous origins and compositions, their effects on nitrogen metabolism, as well as the physiological and biochemical processes involved in these products, this review concludes with an in-depth discussion of the effects of V-PHs on major leafy vegetables. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the occurrence and characteristics of Salmonella isolates in salad vegetables in the United Arab Emirates (UAE). Out of 400 samples tested from retail, only 1.25% (95% confidence interval, 0.41–2.89) were found to be positive for Salmonella, all of which were from conventional local produce, presented at ambient temperature, and featured as loose items. The five Salmonella-positive samples were arugula (n = 3), dill (n = 1), and spinach (n = 1). The Salmonella isolates from the five samples were found to be pan-susceptible to a panel of 12 antimicrobials tested using a disc diffusion assay. Based on whole-genome sequencing (WGS) analysis, only two antimicrobial resistance genes were detected—one conferring resistance to aminoglycosides (aac(6′)-Iaa) and the other to fosfomycin (fosA7). WGS enabled the analysis of virulence determinants of the recovered Salmonella isolates from salad vegetables, revealing a range from 152 to 165 genes, collectively grouped under five categories, including secretion system, fimbrial adherence determinants, macrophage-inducible genes, magnesium uptake, and non-fimbrial adherence determinants. All isolates were found to possess genes associated with the type III secretion system (TTSS), encoded by Salmonella pathogenicity island-1 (SPI-1), but various genes associated with the second type III secretion system (TTSS-2), encoded by SPI-2, were absent in all isolates. Combining the mean prevalence of Salmonella with information regarding consumption in the UAE, an exposure of 0.0131 salmonellae consumed per person per day through transmission via salad vegetables was calculated. This exposure was used as an input in a beta-Poisson dose–response model, which estimated that there would be 10,584 cases of the Salmonella infection annually for the entire UAE population. In conclusion, salad vegetables sold in the UAE are generally safe for consumption regarding Salmonella occurrence, but occasional contamination is possible. The results of this study may be used for the future development of risk-based food safety surveillance systems in the UAE and to elaborate on the importance for producers, retailers, and consumers to follow good hygiene practices, particularly for raw food items such as leafy salad greens. [ABSTRACT FROM AUTHOR]

Weather affects key aspects of bacterial behavior on plants but has not been extensively investigated as a tool to assess risk of crop contamination with human foodborne pathogens. A novel mechanistic model informed by weather factors and bacterial state was developed to predict population dynamics on leafy vegetables and tested against published data tracking Escherichia coli O157:H7 (EcO157) and Salmonella enterica populations on lettuce and cilantro plants. The model utilizes temperature, radiation, and dew point depression to characterize pathogen growth and decay rates. Additionally, the model incorporates the population level effect of bacterial physiological state dynamics in the phyllosphere in terms of the duration and frequency of specific weather parameters. The model accurately predicted EcO157 and S. enterica population sizes on lettuce and cilantro leaves in the laboratory under various conditions of temperature, relative humidity, light intensity, and cycles of leaf wetness and dryness. Importantly, the model successfully predicted EcO157 population dynamics on 4-week-old romaine lettuce plants under variable weather conditions in nearly all field trials. Prediction of initial EcO157 population decay rates after inoculation of 6-week-old romaine plants in the same field study was better than that of long-term survival. This suggests that future augmentation of the model should consider plant age and species morphology by including additional physical parameters. Our results highlight the potential of a comprehensive weatherbased model in predicting contamination risk in the field. Such a modeling approach would additionally be valuable for timing field sampling in quality control to ensure the microbial safety of produce. [ABSTRACT FROM AUTHOR]

• BG produced by Fusarium oxysporum was applied to drought stressed spinach. • Drought stress generated phenolics and their oxidizing enzyme PPO (browning causer). • BG regulated antioxidants and phenolics fulfilling standards for consumer demand. • BG increased spinach's resilience to dehydration via instigating antioxidant capacity. Sustainable agriculture is a major theme of the Food and Agriculture Organization (FAO) Strategic Framework 2022–2031. Using microbial-based regulators is a sustainable organic approach to accomplish food safety. Normally, drought is a menace to most crops' agricultural production, but for leafy green vegetables the matter is more frustrating due to grade standards. Despite breakthroughs in boosting crop tolerance to drought stress, the quest for leafy greens remains restricted. The current report is to study the ability of biologically-produced gibberellin by Fusarium oxysporum in alleviating water stress in leafy vegetable spinach, Spinacia oleracea. Endophytic Fusarium oxysporum demonstrated high gibberellin production by 200±5.9 mg L −1. Water stress (100, 75, 50, 25 % field capacity, FC) generated mild to severe abnormal growth and physiological dynamics. Foliar-applied biological gibberellin (BG) motivated plant yield and quality by boosting various phenotypic and physiological features in terms of plant height, biomass, and number of leaves accompanied by thicker epicuticular wax, balanced water status, higher photosynthetic pigment, increased osmoprotectants. BG shoulders a role in upgrading plant liveness via exacerbating antioxidants (anthocyanin, ascorbic acids, total antioxidants, and flavonoids) joined with activation of secondary metabolizing enzyme phenylalanine ammonia-lyase PAL, fulfilling consumer demand standards for spinach as well as lowering the content of phenolics and its oxidizing enzyme polyphenol oxidas (PPO, browning causer). Catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were instigated thus maintaining electrolyte leakage, cellular O 2 ·−, ·OH, H 2 O 2 , malondialdehyde, and lipid peroxidation at baseline levels. BG appears to reduce nitrative toxicity via enhancing nitrate reductase (NR) activity. BG foliar spray increased spinach's resilience to dehydration and its capacity to produce an adequate upgraded yield while cultivated with reduced water regimes or even exposed to drought. [Display omitted] [ABSTRACT FROM AUTHOR]

The prediction of the maturity date of leafy greens in a planting environment is an essential research direction of precision agriculture. Real-time detection of crop growth status and prediction of its maturity for harvesting is of great significance for improving the management of greenhouse crops and improving the quality and efficiency of the greenhouse planting industry. The development of image processing technology provides great help for real-time monitoring of crop growth. However, image processing technology can only obtain the representation information of leafy greens, and it is difficult to describe the causal mechanism of environmental factors affecting crop growth. Therefore, a framework combining an image processing model and a crop growth model based on causal inference was proposed to predict the maturity of leafy greens. In this paper, a deep convolutional neural network was used to classify the growth stages of leafy greens. Then, since some environmental factors have causal effects on the growth rate of leafy greens, the causal effects of various environmental factors on the growth of leafy greens are obtained according to the data recorded by environmental sensors in the greenhouse, and the prediction results of the maturity of leafy greens in the study area are obtained by combining image data. The experiments showed that the root mean square error (RMSE) was 2.49 days, which demonstrated that the method had substantial feasibility in predicting the maturity for harvesting and effectively solved the limitations of poor timeliness of prediction. This model has great application potential in predicting crop maturity in greenhouses. [ABSTRACT FROM AUTHOR]

There is limited information regarding the use of quinoa fresh leaves as a vegetable. Thus, the objective of this study was to promote quinoa green leaves as a vegetable, as well as to conduct a season extension feasibility study using high tunnels. The study was conducted during the spring seasons of 2020, 2021, and 2022 at the George Washington Carver farm of Lincoln University in Jefferson City, MO, USA. Three quinoa genotypes were used in a randomized complete block design (RCBD) with three replications over three years. Agronomic data and leaf nutritional analyses for young plants approximately 30 days old were evaluated. Among the three quinoa genotypes, genotype Ames 13724 gave the highest yield of leafy greens and was consistent over the three years. Additionally, the use of high tunnels served as a season extension tool by accelerating the production of quality fruits and vegetables outside typical growing seasons. The results indicated that season extension of quinoa leafy greens production in a high tunnel is possible with a three-week earlier harvest in early spring when fewer fresh vegetables are available in the markets. Farmers can increase farm income by selling this specialty vegetable in the early season for premium prices. [ABSTRACT FROM AUTHOR]

In the last years, leafy vegetables cultivated as baby leaves have been established in the market and have attracted the interest of consumers throughout the world. During the growing seasons of 2019 and 2020, 97 isolates of Rhizoctonia solani and 112 isolates of Pythium spp. were obtained from baby leaf vegetables exhibited damping‐off symptoms. Representative isolates of R. solani from each surveyed plant species were characterized using sequence analysis of the internal transcribed spacer (rDNA‐ITS) region. Isolates were identified as belonging to four anastomosis groups (AGs): AG2‐1, AG‐IB, AG4‐HGI and AG4‐HGIII. AG4‐HGI was the most prevalent group and phylogenetic analysis showed that the isolates were distinctly separated according to their AGs. Pathogenicity among the four AGs on 23 plant species varied considerably, from not susceptible to highly susceptible, while, in general, AGs did not exhibit host specificity. Furthermore, a total of 112 Pythium spp. isolates were obtained. The ITS region and the cytochrome oxidase II (coxII) gene were amplified, and three Pythium spp. were identified (P. ultimum, P. aphanidermatum and P. sylvaticum), which were used further for maximum‐likelihood phylogenetic analysis. The pathogenicity of representative isolates was assessed in vitro and in vivo on 10 plant species. In general, all three tested Pythium spp. were virulent when used in vitro, while P. ultimum was the most virulent in vivo. This is the first comprehensive study aimed at determining the occurrence of specific R. solani AGs and Pythium spp. derived from baby leafy vegetables exhibiting damping‐off symptoms in Greece. [ABSTRACT FROM AUTHOR]

Phenotype analysis of leafy green vegetables in planting environment is the key technology of precision agriculture. In this paper, deep convolutional neural network is employed to conduct instance segmentation of leafy greens by weakly supervised learning based on box-level annotations and Excess Green (ExG) color similarity. Then, weeds are filtered based on area threshold, K-means clustering and time context constraint. Thirdly, leafy greens tracking is achieved by bipartite graph matching based on mask IoU measure. Under the framework of phenotype tracking, some time-context-dependent phenotype analysis tasks such as growth monitoring can be performed. Experiments show that the proposed method can achieve 0.95 F1-score and 76.3 sMOTSA (soft multi-object tracking and segmentation accuracy) by using weakly supervised annotation data. Compared with the fully supervised approach, the proposed method can effectively reduce the requirements for agricultural data annotation, which has more potential in practical applications. [ABSTRACT FROM AUTHOR]

This study investigated the effects of root zone (RZ) heat priming on Eruca sativa (cv. Arugula) and Lactuca sativa (cv. Canasta) in a tropical greenhouse by exposing them to three different RZ temperatures (RZTs). For the first group, plants were grown at 25 °C-RZT for 36 days. The second group of plants was grown at 25 °C-RZT for 10 days before transferring to 38 °C-RZT for 10 days and then to 42 °C-RZT for another 16 days (primed). For the third group, plants were grown at 25 °C-RZT for 20 days and for the last 16 days were transferred to 42 °C-RZT (non-primed). RZ heat priming did not affect the leaf expansion of Arugula while the leaf expansion was slower in RZ heat primed Canasta compared to 25 °C-RZT plants. After transferring to 42 °C-RZT in the later stage, RZ heat primed Arugula had similar productivity but a larger root system with higher nutritional quality at harvest and during postharvest storage compared to those of 25 °C-RZT plants. After subjection to 42 °C-RZT, although RZ heat priming enhanced its nutritional quality, the productivity of Canasta was compromised. The results of this study suggest that it is feasible to enhance productivity and nutritional quality of leafy greens at lower production cost through RZT management. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the presence of T. gondii,Cryptosporidium spp. oocysts, and G. duodenalis cysts, in three leafy greens (coriander, lettuce, and parsley) commonly consumed raw. Despite the recognition of the association between the parasitic illnesses and the consumption of contaminated food, there is still a lack of studies investigating the occurrence of parasitic contamination in food matrices. Methods: A total of 152 leafy green samples were collected in Marrakech from April 2018 to October 2019. Parasites were eluted and concentrated before detection of their DNA by real-time qPCR. Results: The analysis revealed an overall rate of contamination of 32.2% (49/152), with 29.6% (45/152) positive for T. gondii and 2.6% (4/152) for G. duodenalis, while none was positive for Cryptosporidium spp. Conclusion: The results showed that humans can be exposed to protozoan parasites through vegetables consumption. Further investigations can be performed to acquire new epidemiological data to assess the public health impact of these protozoan diseases in Morocco. [ABSTRACT FROM AUTHOR]

Mitigation strategies to prevent microbial contamination of crops are lacking. We tested the hypothesis that induction of plant systemic resistance by biological (induced systemic resistance [ISR]) and chemical (systemic acquired resistance [SAR]) elicitors reduces endophytic colonization of leaves by Salmonella enterica serovars Senftenberg and Typhimurium. S. Senftenberg had greater endophytic fitness than S. Typhimurium in basil and lettuce. The apoplastic population sizes of serovars Senftenberg and Typhimurium in basil and lettuce, respectively, were significantly reduced approximately 10- to 100-fold by root treatment with microbial inducers of systemic resistance compared to H2O treatment. Rhodotorula glutinis effected the lowest population increases of S. Typhimurium in lettuce and S. Senftenberg in basil leaves, respectively 120- and 60-fold lower than those seen with the H2O treatment over 10 days postinoculation. Trichoderma harzianum and Pichia guilliermondii did not have any significant effect on S. Senftenberg in the basil apoplast. The chemical elicitors acidobenzolar-S-methyl and DL-b-amino-butyric acid inhibited S. Typhimurium multiplication in the lettuce apoplast 10- and 2-fold, respectively, compared to H2O-treated plants. All ISR and SAR inducers applied to lettuce roots in this study increased leaf expression of the defense gene PR1, as did Salmonella apoplastic colonization in H2O-treated lettuce plants. Remarkably, both acidobenzolar-S-methyl upregulation and R. glutinis upregulation of PR1 were repressed by the presence of Salmonella in the leaves. However, enhanced PR1 expression was sustained longer and at greater levels upon elicitor treatment than by Salmonella induction alone. These results serve as a proof of concept that priming of plant immunity may provide an intrinsic hurdle against the endophytic establishment of enteric pathogens in leafy vegetables. [ABSTRACT FROM AUTHOR]

The Food Safety Modernization Act (FSMA) includes a time-to-harvest interval following the application of noncompliant water to preharvest produce to allow for microbial die-off. However, additional scientific evidence is needed to support this rule. This study aimed to determine the impact of weather on the die-off rate of Escherichia coli and Salmonella on spinach and lettuce under field conditions. Standardized, replicated field trials were conducted in California, New York, and Spain over 2 years. Baby spinach and lettuce were grown and inoculated with an 104-CFU/ml cocktail of E. coli and attenuated Salmonella. Leaf samples were collected at 7 time points (0 to 96 h) following inoculation; E. coli and Salmonella were enumerated. The associations of die-off with study design factors (location, produce type, and bacteria) and weather were assessed using log-linear and biphasic segmented log-linear regression. A segmented log-linear model best fit die-off on inoculated leaves in most cases, with a greater variation in the segment 1 die-off rate across trials ( 0.46 [95% confidence interval {95% CI}, -0.52, -0.41] to -6.99 [95% CI, -7.38, -6.59] log10 die-off/day) than in the segment 2 die-off rate (0.28 [95% CI, -0.20, 0.77] to -1.00 [95% CI, -1.16, -0.85] log10 die-off/day). A lower relative humidity was associated with a faster segment 1 die-off and an earlier breakpoint (the time when segment 1 die-off rate switches to the segment 2 rate). Relative humidity was also found to be associated with whether die-off would comply with FSMA's specified die-off rate of -0.5 log10 die-off/day. [ABSTRACT FROM AUTHOR]

Leafy greens, especially lettuce, are repeatedly linked to foodborne outbreaks. This paper studied the susceptibility of different leafy greens to human pathogens. Five commonly consumed leafy greens, including romaine lettuce, green-leaf lettuce, baby spinach, kale, and collard, were selected by their outbreak frequencies. The behavior of E. coli O157:H7 87-23 on intact leaf surfaces and in their lysates was investigated. Bacterial attachment was positively correlated with leaf surface roughness and affected by the epicuticular wax composition. At room temperature, E. coli O157:H7 had the best growth potentials on romaine and green-leaf lettuce surfaces. The bacterial growth was positively correlated with stomata size and affected by epicuticular wax compositions. At 37 °C, E. coli O157:H7 87-23 was largely inhibited by spinach and collard lysates, and it became undetectable in kale lysate after 24 h of incubation. Kale and collard lysates also delayed or partially inhibited the bacterial growth in TSB and lettuce lysate at 37 °C, and they sharply reduced the E. coli O157:H7 population on green leaf lettuce at 4 °C. In summary, the susceptibility of leafy greens to E. coli O157:H7 is determined by a produce-specific combination of physiochemical properties and temperature. • Lysate will not affect E. coli O157:H7 growth and survival on intact leaves. • E. coli 's survival on leaves depends on produce-specific traits and temperature. • Spinach, collard, kale lysates are natural antimicrobials against E. coli O157:H7. • At 37 °C, kale lysate inactivated E. coli O157:H7 in pure culture within 24h. • Kale and collard lysates reduced E. coli population on the lettuce surface at 4 °C. [ABSTRACT FROM AUTHOR]

Sole-source lighting with light-emitting diodes (LEDs) incurs high operating expenditure in indoor vertical farms, where crops are typically grown under diurnal light at a fixed photosynthetic photon flux density (PPFD). Under the same daily light integral (DLI), continuous light lowers the needed PPFD, thereby decreasing the initial capital investment on high-output LEDs and operating expenditure by lighting in the nighttime, when electricity rates are lower than in the daytime in some areas. However, little is known about how temporal light patterns influence baby green growth at varying DLIs. We performed an indoor experiment on baby greens of lettuce (Lactuca sativa) 'Rouxai', kale (Brassica oleracea var. acephala) 'Red Russian', and arugula (Eruca sativa) 'Astro' at ≈ 21 ºC air temperature and ≈ 70% relative humidity. At each of two DLIs (8.64 and 17.28 mol∙m–2∙d–1), each crop was grown under warm-white LEDs with three light patterns [100%, 75%, and 50% daytime DLI (first half of a 24-hour cycle), followed by 0%, 25%, and 50% nighttime DLI, respectively]. The 0% nighttime DLI treatments delivered diurnal light with a 12-h photoperiod, whereas the 25% and 50% nighttime DLI treatments delivered alternating light and continuous light, respectively, both with a 24-h photoperiod. Lettuce and kale generally had more pronounced growth responses to the light pattern under the higher DLI, whereas arugula growth was unaffected by the light pattern. Compared to diurnal light, continuous light increased lettuce shoot mass at both DLIs, but increased kale shoot mass only under the higher DLI. Compared to continuous light, alternating light decreased lettuce shoot mass only under the higher DLI, but did not influence most parameters of kale or arugula. Doubling the DLI increased the shoot dry mass of all crops by 44–150% and the shoot fresh mass of arugula by 38–73% across light patterns. The shoot fresh mass of lettuce and kale increased with an increasing DLI under continuous or diurnal light. We conclude that the light pattern and DLI had interactive and crop-specific effects on the growth of baby greens. Under the same DLI, continuous light can increase growth of lettuce and kale, but not arugula, baby greens over diurnal light, especially under a high DLI. • Continuous light promotes growth of some baby greens over diurnal light. • The advantages of continuous light are more pronounced under high light. • Lettuce and kale are more responsive to temporal light patterns than arugula. • Increasing the daily light integral increases growth of baby greens. [ABSTRACT FROM AUTHOR]

Background: Zoonotic taeniid cestodes are amongst the most important food-borne parasites affecting human health worldwide. Contamination of fresh produce with the eggs of Echinococcus granulosus (s.l.), Echinococcus multilocularis, and some Taenia species pose a potential food safety risk. However, very few studies have attempted to investigate the potential contamination of fresh produce with taeniid eggs and the available methods are not standardized for this purpose. Established protocols do exist for testing leafy greens and berries for contamination with protozoan parasites and are used in national surveillance programmes. This methodology could be suitable for the detection of taeniids. The objective of this project was to develop and standardize a sensitive and reliable method to detect contamination of leafy greens and berries with eggs of zoonotic taeniids and to differentiate between E. multilocularis, E. granulosus (s.l.) and Taenia spp. Methods: We compared the efficacy of different wash solutions to remove Taenia spp. eggs from spiked produce, assessed two DNA extraction kits for their performance on Taenia spp. eggs, and adapted a published conventional multiplex PCR into a real-time PCR with fluorescence melting curve analysis (MCA) that was optimized for use on produce washes. Analytical specificity of this protocol was assessed using non-spiked produce washes as well as a variety of other potentially contaminating parasites. Results: The protocol as established in this study had an analytical sensitivity of detecting five eggs per spiked sample for both romaine lettuce and strawberries. Unequivocal identification of E. multilocularis, E. granulosus (s.l.) and Taenia spp. was possible through MCA. Amplicon sequencing allowed identification of Taenia to the species level. The real-time PCR also amplified DNA from Dicrocoelium sp., but with a clearly discernable melting curve profile. Conclusion: The new protocol for screening produce for taeniid contamination was highly sensitive. Melting curve analysis and the possibility of amplicon sequencing made this assay very specific. Once further validated, this method could be employed for surveillance of produce for contamination with taeniid parasites to assess potential risks for consumers. [ABSTRACT FROM AUTHOR]

At present, trends exist in the production of food for the benefit of human health. The negative effect of an excessive intake of nitrates accumulated in vegetables is well known, causing worldwide concern. Light plays an important role in the accumulation of this ion. The objective of this work was to evaluate the effect of light-emitting diode (LED) spectra used in artificial lighting for horticulture on the accumulation of nitrates in leafy and root vegetables compared with the effects with white LED lights. Two independent experiments were carried out in the culture chamber. In Expt. 1, six species of nitrate accumulators were used: arugula, spinach, lettuce, endive, radish, and beetroot. In Expt. 2, four lettuce cultivars were used. In both experiments, the treatments were two spectra--T1 = AP67 Valoya® and the control (T0) = white Roblan®--at two illumination intensities [high (H) and low (L)] with a 16/8-hour (day/night) photoperiod. The fresh biomass and the concentration of nitrates were measured at 35 days of treatment posttransplantation. An important and significant increase of 50% of the mean fresh weight was obtained in all the species when the light intensity increased. Except for spinach in the low-intensity treatment, all nitrate content values were less than the maximum limits of European regulation. The nitrate content generally decreased with increasing intensity, and this benefit was greater in the T1 treatment. T0 showed a reduction in the nitrate content compared with T1 in only one case, which was the H in beetroot. A large and significant reduction was observed in the nitrate content in T1. For L in Expt. 1, the nitrate decrease was 18%, whereas for H, it was 35%. In Expt. 2, the decrease in the nitrate content was 10% for L and 21% for H. A greater benefit was derived when using the photosynthetic spectrum in the growing chambers under low light intensity. [ABSTRACT FROM AUTHOR]

Shiga toxin-producing Escherichia coli (STEC) is a major cause of foodborne illness, ranging from mild diarrhea to permanent kidney failure. This study summarizes the results of four surveys performed at different time periods, which investigated the occurrence and characteristics of STEC in beef, lamb and leafy greens available in the Swedish retail market. Such data is required when assessing the public health risk of varying types of STEC in different foods, and for establishing risk management measures. Samples from domestic and imported products were collected based on their availability in the retail market. The occurrence of STEC was investigated in 477 samples of beef, 330 samples of lamb and 630 samples of leafy greens. The detection of virulence genes (stx 1 , stx 2 , eae) was performed using real-time PCR followed by the isolation of bacteria from stx -positive enriched samples using immunomagnetic separation or an immunoblotting method. All STEC isolated from the food samples was further characterised in terms of stx subtyping and serotyping through whole genome sequencing. STEC was isolated from 2 to 14 % of beef samples and 20 to 61 % of lamb samples, depending on the region of origin. STEC was not isolated from samples of leafy greens, although stx genes were detected in 11 (2 %) of the samples tested. In total, 5 of the 151 sequenced STEC isolates from meat contained stx2 and eae , of which 4 such combinations had the stx 2a subtype. The stx 2 gene, stx 2a in particular, is strongly associated with serious disease in humans, especially in combination with the eae gene. The isolates belonged to 20 different serotypes. Two isolates from beef and one from lamb belonged to the serotype O157:H7 and contained genes for stx 2 and eae. Overall, several combinations of stx subtypes were found in isolates from beef, whereas stx 1c , either alone or together with stx 2b , was the dominant combination found in STEC from lamb. In conclusion, STEC was rare in whole meat samples of domestic beef in the Swedish retail market, whereas such bacteria were frequently found in minced meat and whole meat samples of imported beef and domestic and imported lamb. Although the number of isolates containing genes linked to an increased risk of severe disease was low, beef and lamb in the Swedish retail market is a common source of human exposure to potentially pathogenic STEC. • The stx2a subtype in combination with eae occurred in STEC from both beef and lamb. • Beef and lamb sold in Sweden is a common source of exposure to potentially pathogenic STEC. • No STEC was found in leafy greens sold on the Swedish retail market. • The use of immunoblotting contributed to the high isolation frequency of STEC. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Stomatal movement and bacterial persistence are affected by plant-bacterium interaction. • SL1344 is not adapted to overcome the basic stomatal immune response of all plants. • The effect of humidity on O157:H7 survival is dependent on the plant genotype tested. • Stomatal response to SL1344 may be dependent on the environmental conditions. • Internalized pathogens can survive inside lettuce leaves until senescence. Abstract Human pathogens can internalize and persist inside crop plants leading to foodborne outbreaks and illnesses. Pathogenic bacteria might use natural openings on the plant surface, such as the stomatal pore, to penetrate the leaf interior and colonize the intercellular space. Once internalized, these pathogens often escape current sanitation procedures that are mostly efficient to clean the plant surface. Plants have evolved mechanism to quickly perceive the presence of bacteria and close the stomatal pore, potentially diminishing leaf contamination. In this study, we assessed the ability of several fresh leafy greens in mounting stomatal immunity against Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium (STm) SL1344 and determined the influence of environmental conditions (light, temperature, and humidity) on the effectiveness of the stomatal response and bacterial persistence in the leaf. We observed that, independent of the air relative humidity (RH), E. coli O157:H7 induces stomata closure in Butter Lettuce, Romaine, Basil, Spinach, and Cilantro when compared to the water control. However, STm SL1344 induces a variable stomatal response in different plant species and environmental conditions. Furthermore, endophytic STm 1344 population increases with high RH independently of other environmental conditions, whereas O157:H7 population size significantly increases in Romaine and Spinach only under post-harvest conditions. The phenotypic variability observed among the various STm-plant interactions provides opportunities to discovering the underlying genetic basis of both the plant and the pathogen, as well as to proposing additional plant-specific control measure to reduce pathogen load on/in leafy greens. [ABSTRACT FROM AUTHOR]

Abstract: We developed a probabilistic mathematical model for the postharvest processing of leafy greens focusing on Escherichia coli O157:H7 contamination of fresh‐cut romaine lettuce as the case study. Our model can (i) support the investigation of cross‐contamination scenarios, and (ii) evaluate and compare different risk mitigation options. We used an agent‐based modeling framework to predict the pathogen prevalence and levels in bags of fresh‐cut lettuce and quantify spread of E. coli O157:H7 from contaminated lettuce to surface areas of processing equipment. Using an unbalanced factorial design, we were able to propagate combinations of random values assigned to model inputs through different processing steps and ranked statistically significant inputs with respect to their impacts on selected model outputs. Results indicated that whether contamination originated on incoming lettuce heads or on the surface areas of processing equipment, pathogen prevalence among bags of fresh‐cut lettuce and batches was most significantly impacted by the level of free chlorine in the flume tank and frequency of replacing the wash water inside the tank. Pathogen levels in bags of fresh‐cut lettuce were most significantly influenced by the initial levels of contamination on incoming lettuce heads or surface areas of processing equipment. The influence of surface contamination on pathogen prevalence or levels in fresh‐cut bags depended on the location of that surface relative to the flume tank. This study demonstrates that developing a flexible yet mathematically rigorous modeling tool, a “virtual laboratory,” can provide valuable insights into the effectiveness of individual and combined risk mitigation options. [ABSTRACT FROM AUTHOR]

Faecal contaminated fruits and vegetables have been linked to several outbreaks of foodbourne diseases. In-field detection of faecal matter would allow the producer to take action to reduce faecal contaminated produce entering the post-harvest processing line and the human food supply. No viable systems to accomplish this task have been developed to date. To address this, a prototype imaging system was developed to detect faecal matter on leafy greens. The system principally comprised of two monochrome cameras that were used to simultaneously capture images of the same target at two separate wavelengths, 690 and 710 nm, by utilising a beam-splitter and bandpass filters. The 710 nm and 690 nm waveband images were used for pixel-by-pixel calculation of a ratio image of the target, to which a thresholding technique was applied to classify pixels as either faecal matter or non-faecal matter. The system was tested on spinach leaves ( Spinacia olerace ) and three types of soils in an outdoor environment. On all samples evaluated, the imaging system, coupled with this waveband ratio normalisation method, successfully distinguished faecal matter from spinach leaves and soil under varying atmospheric conditions. These findings are very encouraging and further study is needed to determine if such a technique would reliably detect faecal material in an agricultural field environment where leaf orientation and contamination concentration levels are highly variable. Highlights • Prototype imaging system developed to detect faecal matter on leafy greens and soil. • The system captured images at 690 and 710 nm using monochromatic cameras. • Developed image algorithm created a single image from the ratio of 710:690 nm. • Developed image algorithm successfully identified faecal contaminated locations. [ABSTRACT FROM AUTHOR]

Leafy greens are frequently implicated in foodborne disease outbreaks and cut-leafy greens are a food that requires time and temperature control for safety. Predictive microbiology uses mathematical models to predict the growth of bacteria based on environmental conditions. The objective of our study was to compare published square root growth models for Salmonella (n = 6), pathogenic E. coli (n = 6) and Listeria monocytogenes (n = 4) using real world transport temperature data. Data from trucks transporting fresh-cut leafy greens during cross-country shipments were used as temperature inputs to the models. Bacterial growth was computed using the temperatures from each probe in every truck over the duration of transit, which resulted in 12–18 growth predictions per truck for each model. Each model generally gave significantly different predictions than other models for the same organism. The exception was for the two Salmonella models predicting the least growth and the two Salmonella models predicting the most growth which gave predictions that were not significantly different. Although different models tended to give different predictions, their ability to rank risk by truck was generally consistent across models. While absolute risk might be dependent upon choice of model, relative risk is independent of model choice. • Two Salmonella models predicting the least growth gave similar predictions • Two Salmonella models predicting the most growth gave similar predictions • Six E. coli models gave significantly different predictions from one another • Four L. monocytogenes models also gave significantly different predictions • Models tended to rank different trucks similarly despite different predictions [ABSTRACT FROM AUTHOR]

Leafy greens have been associated with foodborne disease outbreaks in different countries. To decrease microbial contamination of leafy greens, chemical agents are commonly used; however, a number of studies have shown these agents to have limited antimicrobial effect against pathogenic bacteria on vegetables. The objective of this study was to compare the antibacterial effect of Hibiscus sabdariffa calyx extracts (water, methanol, acetone, and ethyl acetate), sodium hypochlorite, acetic acid, and colloidal silver against foodborne bacteria on leafy greens. Thirteen foodborne bacteria were used in the study: Listeria monocytogenes, Shigella flexneri, Salmonella serotypes Typhimurium Typhi, and Montevideo, Staphylococcus aureus, Escherichia coli O157:H7, five E. coli pathotypes (Shiga toxin-producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative), and Vibrio cholerae O1. Each foodborne bacterium was separately inoculated on romaine lettuce, spinach, and coriander leaves. Separately, contaminated leafy greens were immersed in four hibiscus extracts and in sanitizers for 5 min. Next, green leaves were washed with sterile tap water. Separately, each green leaf was placed in a bag that contained 0.1% sterile peptone water and was rubbed for 2 min. Counts were done by plate count using appropriate dilutions (in sterile peptone water) of the bacterial suspensions spread on Trypticase soy agar plates and incubated at 35 ± 2°C for 48 h. Statistically significant differences ( P < 0.05) were calculated with an analysis of variance and Duncan's test. All 13 foodborne bacteria attached to leafy greens. Roselle calyx extracts caused a significantly greater reduction ( P < 0.05) in concentration of all foodborne bacteria on contaminated romaine lettuce, spinach, and coriander than did the sodium hypochlorite, colloidal silver, and acetic acid. Dry roselle calyx extracts may potentially be a useful addition to disinfection procedures for romaine lettuce, spinach, and coriander. [ABSTRACT FROM AUTHOR]

Leafy greens contaminated with Salmonella enterica have been linked to large number of illnesses in many countries in recent years. Listeria monocytogenes is also a pathogen of concern for leafy greens because of its prevalence in the growing and processing environment and its ability to grow at refrigeration temperatures. Experimental data for the growth and survival of S . enterica and L . monocytogenes under different conditions and storage temperatures were retrieved from published studies. Predictive models were developed using the three-phase linear model as a primary growth model and square-root model to calculate specific growth rate (ln CFU g − 1 h −1 ) at different temperatures (°C). The square-root model for S . enterica was calculated as μ = (0.020(Temperature + 0.57)) 2 . The square-root model for L . monocytogenes was fitted as μ = (0.023(Temperature-0.60)) 2 . The growth-survival model for S . enterica and growth model for L . monocytogenes were validated using several dynamic time-temperature profiles during the production and supply chain of leafy greens. The models from this study will be useful for future microbial risk assessments and predictions of behavior of S . enterica and L . monocytogenes in the leafy greens production and supply chain. [ABSTRACT FROM AUTHOR]

Leafy green vegetables are highly susceptible to microbial contamination because they are minimally processed. Pathogenic bacteria of concern include Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes . Leafy greens are a highly perishable commodity, and in some cases have a postharvest shelf-life limited to one week. This study provides an approach to optimize storage temperature of leafy greens in the supply chain, considering the cost of refrigeration, sensory quality parameters (i.e., fresh appearance, wilting, browning, and off-odor), and microbial safety using nonlinear programming (NLP). The loss of sensory quality parameters was expressed as Arrhenius equations and pathogen growth were represented by three-phase linear (primary) and square-root (secondary) models. The objective function was refrigeration cost, which was to be minimized. The constraints were growth of pathogens and the loss of sensory characteristics. An interactive graphical user interface was developed in MATLAB. Pathogen growth is of more concern than loss of sensory quality in fresh-cut Iceberg lettuce when considering a shelf-life of up to two days, and the model indicates is difficult to maintain sensory qualities for longer shelf-life values. Browning is of maximum concern for fresh-cut Iceberg and Romaine lettuce, whereas off-odor is the biggest concern for fresh-cut chicory. [ABSTRACT FROM AUTHOR]

Recent outbreaks linked to contaminated leafy greens underline the need for identifying effective natural approaches to improve produce safety at pre-harvest level. Lactic acid bacteria (LAB) have been evaluated as biocontrol agents in food products. In this study, the efficacy of a cocktail of LAB including Lactococcus lactis , Lactiplantibacillus plantarum , Lactobacillus johnsonii , and Lactobacillus acidophilus as pre-harvest biocontrol agents against Listeria and Escherichia coli O157 on lettuce and spinach was investigated. Bacterial pathogens L. monocytogenes and E. coli O157:H7 and the non-pathogenic surrogates L. innocua and E. coli O157:H12 were used to spray-inoculate cultivars of lettuce and spinach grown in growth chamber and in field, respectively. Inoculated plants were spray-treated with water or a cocktail of LAB. On day 0, 3, and 5 post-inoculation, four samples from each group were collected and bacterial populations were determined by serial dilution and spiral plating on selective agars. LAB treatment exhibited an immediate antimicrobial efficacy against L. monocytogenes and E. coli O157:H7 on "Green Star" lettuce by ~2 and ~ 1 log reductions under growth chamber conditions, respectively (P < 0.05). The effect of LAB against E. coli O157:H7 on "New Red Fire" lettuce remained effective during the 5-day period in growth chamber (P < 0.05). Treatment of LAB delivered an effective bactericidal effect against E. coli O157:H12 immediately after application on the field-grown lettuce plants (P < 0.05). Approximately 1 log L. innocua reduction was observed on "Matador" and "Palco" spinach on day 5 (P < 0.05). Results of this study support that LAB could potentially be applied as biocontrol agents for controlling Listeria and E. coli O157 contamination on leafy greens at the pre-harvest level. • LAB inactivated Listeria and E. coli O157 on spinach and lettuce. • Leafy green cultivars affected the effectiveness of LAB against foodborne pathogens. • LAB could potentially be used for improving leafy green safety at farm. [ABSTRACT FROM AUTHOR]

Leafy green vegetables, a popular and an indispensable ingredient of the daily menus of Egyptians' diets, currently presents a great concern in terms of microbiological hazards. To the best of our knowledge, this is the first report that provides scientific evidence for prevalence of shiga-toxigenic Escherichia coli (STEC) in leafy greens sold at open air local retail markets and superstores in the Egyptian environment. A total of 486 conventional and organic leafy green samples that are eaten raw were collected from different areas in Alexandria, evaluated for total E. coli counts (ECCs), and screened for E. coli O157:H7 using conventional and molecular methods. Recovery of E. coli (≥ 10 2 CFU/g) from all studied types of leafy greens was indicative of fecal contamination. Total ECCs in conventional samples ranged from 5.47 to 2.56 log CFU/g. Based on their inability to ferment sorbitol on CT-SMAC media, 26 presumptive E. coli O157 isolates were detected in 71.4% (270/378) of the studied conventional samples. From all studied organic samples, only 2 types (organic cabbage and parsley, 16.7%) were contaminated with presumptive E. coli O157. All 28 isolates were further serotyped as E. coli O157 by latex agglutination test, and biochemically confirmed as E. coli . Multiplex PCR assays confirmed the ability of 21.4% (6/28) of the E. coli O157 strains to produce shiga-toxins (Stxs), and their virulence markers were as follows: stx 1 , 66.6% (4/6); stx 2 , 50% (3/6); stx 1 / stx 2 , 16.7% (1/6); eaeA , 83.3% (5/6); and hlyA , 16.7% (1/6). Only 2 strains recovered from conventional and organic parsley could possibly be classified as E. coli O157:H7 based on the presence of stx -genes (either stx 1 or stx 2 or both). Results of the present research highlight that high E. coli loads, together with recovery of STEC O157 isolates could pose serious health risks to the produce consumers. This emphasizes the urgent need for health authorities to value and utilize the existing knowledge to identify strategies that reduce microbiological risks due to fecal contamination of agricultural products, and implement control measures at all stages of the food chain to specifically eliminate the presence of STEC O157 on the leafy green category. [ABSTRACT FROM AUTHOR]

The diverse matrices pose great challenges for rapid detection of low Salmonella level (<10 CFU) in fresh produce. The applicability of microarray-based PathogenDx system for detecting low contamination of Salmonella Newport from leafy greens was evaluated. A pre-PCR preparation protocol including enrichment in universal pre-enrichment broth for 3 h followed by sample concentration using an InnovaPrep bio-concentrator or 6 h enrichment without a concentration step was used for detecting S. Newport from leafy greens with initial inoculum level at ∼6 CFU/25 g. Among 205 samples tested, 98%, 93%, 76%, and 60% of Romaine lettuce, Iceberg lettuce, kale, and spinach samples were tested positive after 3 h of enrichment with sample concentration. After 6 h of enrichment, 100%, 98%, 90%, and 82% of Romaine lettuce, Iceberg lettuce, kale, and spinach samples were positive. The samples were parallelly tested by the FDA bacterial analytical manual (BAM) method and 100% of spiked produce samples were tested positive. The overall analysis time of this methodology was between 8 and 11 h, including all pre-enrichment and concentration steps, in contrast to 4–5 days required for BAM method. The system correctly differentiated all 108 Salmonella strains and 35 non- Salmonella strains used in the study. This novel microarray approach provides a rapid method for detecting Salmonella in leafy greens. • PathogenDx system differentiated 108 Salmonella and 36 non- Salmonella isolates. • Microarray PathogenDx system could be used for detecting Salmonella in leafy green. • 3 h enrichment with concentration detected 98% of Salmonella from Romaine lettuce. • 6 h enrichment detected 100% of Salmonella from Romaine lettuce at 6 CFU/25 g. • Total analysis time was between 8 and 11 h. [ABSTRACT FROM AUTHOR]

Abstract: Consumer demand for fresh produce has increased; however, multiple microbial foodborne outbreaks in the past decade have involved fresh leafy greens. While large farms may process their own leafy greens or use an external processor that uses aqueous sanitizers, small farms may not have these options. Hence, it is important to equip small farmers with simple and effective methods to reduce on-farm pathogen contamination. The goal of this study was to develop a novel device that can improve post-harvest practices on small farms growing leafy greens. A survey was administered to identify farmers' concerns associated with the post-harvest phase of production. The results indicated that most farmers do not wash leafy greens in a sanitizing solution, but would like information on how to improve the safety of their produce. As a result of this survey, a novel sanitizing device was developed to wash, sanitize (with diluted white vinegar containing acetic acid (AA)), and dry leafy greens. The result showed that 1.6% AA for 2 min was effective against coliforms, yeast, mold, and pathogenic surrogates (Listeria, Salmonella, and Escherichia coli). Significant reduction of aerobic bacteria and coliforms were observed at 2.5% AA for 2 min and 1.6% for 2 min treatment at 3 log CFU/g and 2.28 log CFU/g respectively. The use of this device may help farmers wash and sanitize fresh leafy greens effectively, reduce the risk of foodborne pathogen contamination, and improve produce shelf-life. [Copyright &y& Elsevier]

Light recommendations for horticultural crops often focus on the optimal daily light integral (DLI) without regard to how that light is delivered throughout each day. Because photosynthesis is more efficient at lower photosynthetic photon flux density (PPFD), we hypothesized that longer photoperiods with lower PPFD results in faster growth than shorter photoperiods with higher PPFD and the same DLI. We quantified the effect of different photoperiods, all providing the same DLI, on photosynthesis and growth of two leafy greens. Mizuna (Brassica rapa var. japonica) and lettuce (Lactuca sativa) "Little Gem" were grown from seed in a controlled environment chamber (20 °C and 819 µmol·mol−1 CO2) under six photoperiods (10, 12, 14, 16, 18, and 20 h). LED fixtures provided white light and PPFD was adjusted so each treatment received a DLI of 16 mol·m−2·d−1. Mizuna and lettuce were harvested 30 and 41 days after planting, respectively. Longer photoperiods with lower PPFD increased light interception, chlorophyll content index, quantum yield of photosystem II, and aboveground biomass, but decreased instantaneous CO2 assimilation of lettuce and mizuna. Aboveground biomass increased 16.0% in lettuce and 18.7% in mizuna in response to increasing the photoperiod from 10 to 20 h. In summary, extending the photoperiod and lowering PPFD increases growth of lettuce and mizuna by increasing light interception and the quantum yield of photosystem II. [ABSTRACT FROM AUTHOR]

Advances in large hydroponic production of leafy greens, easy adoption in urban agriculture, and large leaf surface area of many leafy greens, greatly increase their exposure to heavy metals and nanoparticles. Cadmium (Cd) and lead (Pb) are two highly toxic heavy metals, which threaten the health of humans and livestock even at trace levels. These heavy metals may be taken up by plant roots through the protein transporters used for essential minerals such as iron (Fe2+) and copper (Cu2+). Previous studies have shown that some metallic nanoparticles affect the performance of protein transporters and modify the plant uptake of co-existing heavy metal ions. This study aims to understand the role of zinc oxide nanoparticles (ZnONPs) in the uptake pattern of Cd and Pb and two key micronutrients of iron and copper in edible tissues of three leafy green species including spinach (Spinaciae oleracea), parsley (Petroselinum sativum) and cilantro (Coriandrum sativum). Pre-grown plant seedlings in soil (containing Cu and Fe) were transplanted to a hydroponic system (1/4th Hoagland solution) for 7 days as a transition, and then were exposed to four treatments in deionized water (1.0 mg L−1 Cd2++100.0 mg L−1 Pb2+, 1.0 mg L−1 Cd2++100.0 mg L−1 Pb2+ + 100 mg L−1 ZnONPs, 100 mg L−1 ZnO-ENPs and a control with no chemical exposure) for additional two weeks. At termination, shoots were gently separated from the roots, and the concentrations of Pb, Cd, Fe, Zn, and Cu in all plant tissues were quantified by inductively coupled plasma-mass spectrometry (ICP-MS). The results revealed that ZnONPs mitigated the uptake of both heavy metals in roots. The translocation of heavy metals was similar in the edible tissues of three species. The response of three leafy greens to the co-exposure of heavy metals and ZnONPs was different in Cu and Fe accumulation in edible tissues. Fe concentration in edible tissues in the co-exposed plants was increased in spinach (+10%) and cilantro (+9%) but decreased in parsley (−8%) compared to controls, while the Cu level in edible tissues increased in all three species following the order of cilantro (+8%)> spinach (+4%)> parsley (+1.5%). Image 1 • Zinc oxide nanoparticles mitigated the uptake of cadmium and lead in roots of leafy greens. • Cu level in edible tissues of leafy greens was elevated in exposure to the zinc oxide nanoparticles. • Uptake pattern of Cd and Pb in coexistence with zinc oxide nanoparticles was similar in leafy greens. • Zinc oxide nanoparticles may reduce the efflux of micronutrients in leafy greens. [ABSTRACT FROM AUTHOR]

• Six individuals in Iowa measured cup weights of ten raw, leafy vegetables (LV). • Iowa cup weights were significantly lower than SR28, FNDDS 2013–14 and the label. • One Iowa cup-equivalent of most LV had fewer nutrients (A, C, K, folate, Mn) at 20% DV. • The 85 g RACC is equivalent to 4.4–6.2 cups of the lighter LVs. • Establishment of a new RACC for these LVs should be considered. Raw dark-green leafy vegetables (LVs) are excellent sources of vitamins A, C, K, folate and manganese. LV intake is reported in cups in the United States (US) and inaccurate cup weights could impact calculated nutrient composition. This project measured the cup weight of ten raw LVs purchased in Coralville, Iowa, compared them to weights reported in two US databases and the Nutrition Facts Label, and assessed changes in nutrient levels for a two-cup serving (one cup-equivalent, c-eq). Six individuals measured one package/head/bunch of each LV. Loosely/moderately packed pieces were weighed in a measuring cup to the nearest 0.1 g. Ready-to-eat produce was measured as purchased; heads/bunches were cut/torn into 2.5-cm pieces. All cup weights were significantly lower than weights previously reported (p < 0.05). Cup weights for seven LVs were <20 g. Highest weights were for Dole® Garden Salad and bok choy. Coefficients of variation between and within measurers were <16% except chopped parsley (35.3% between). LVs except leaf lettuce had one to three fewer nutrients (A, C, folate, manganese) at ≥20% Daily Value for one c-eq at the Iowa cup weight. New Iowa measured cup weights are lower than previously reported, which impacts the calculated nutrient composition. [ABSTRACT FROM AUTHOR]

The 2006 Escherichia coli outbreak in spinach prompted the implementation of unprecedented production strategies (Arizona Leafy Green Products Shipper Marketing Agreement) to minimize microbial risk in leafy greens. As the new procedures require assessments of physical intrusion and excrement in fields, outreach was initiated to educate adult (20-35, 35-50, and > 50 years) Yuma, Arizona residents about these guidelines and animal (e.g., pets, horses) stewardship. Pre- and post-assessments revealed that while sensitivity to fresh produce safety improved, adults over 35 years were more industry responsive. Citizen-based outreach programs, in communities where fresh produce is grown, could benefit field-level safety mitigation. [ABSTRACT FROM AUTHOR]