Detection of enteroparasites in foliar vegetables commercialized in street- and supermarkets in Aparecida de Goiânia, Goiás, Brazil

Foliar vegetables contaminated with fecal residues are an important route of transmission of intestinal parasites to humans. The aim of this study was to evaluate the presence of parasitic forms of protozoa and helminths on lettuces (Lactuca sativa) and collard greens (Brassica oleracea) sold in street- and supermarkets in the city of Aparecida de Goiânia, Goiás, Brazil. A total of 30 samples of each vegetable (15 samples from each supermarkets and street markets) was analyzed. All samples were processed by spontaneous sedimentation method and centrifugal flotation. In 45% of the samples, immature forms of intestinal parasites were identified with 66.7% helminths eggs and 33.3% protozoan cysts or oocysts. Significantly more lettuce samples were contaminated with eggs, cysts or oocyst of at least one parasite than collard green samples (U=216; Z=-3.45; P <0.001). The parasitic forms were identified morphologically up to the family level with eggs of Ancylostomatidae, Strongyloididae, Ascarididae and Taeniidae, or oocysts of Eimeriidae, to the genus with Cystoisospora sp. and Toxocara sp., and to the species level with Cystoisospora canis, Dipylidium caninum and Hymenolepis nana. The presence of these infective agents in lettuce and collard green from both street- and supermarkets highlights the high risk of spreading parasites by eating raw vegetables sold in Aparecida de Goiânia.

CHICORY AND ARUGULA IN INTERCROPPING WITH COLLARD GREENS1

ABSTRACT Vegetable intercropping systems use complementarity between species to increase agricultural profitability. This study evaluated the effects of intercropping chicory and arugula species with collard greens on crop yield and land use efficiency (LUE). Six treatments, consisting of species planted as monocultures or intercropped in various combinations, were evaluated in a randomized block design with four replicates. The cultivars ‘Top Bunch’ (collard greens), ‘Pão de Açúcar’ (chicory) and ‘Folha Larga’ (arugula) were used. The yield of collard greens in monoculture did not differ from those obtained when they were intercropped with chicory, arugula, or both species, whereas chicory and arugula yields were higher in monoculture. However, even with yield losses for chicory and arugula in intercropping, LUE indices were greater than 1.0 in all intercropping systems, indicating their viability. The highest LUE index (2.41) was obtained in the chicory-arugula-collard green intercropping system.

Collard greens and chicory intercropping efficiency as a function of chicory (Cichorium intybus) transplant time

Vegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens. Highlights: The collard green yield increased by 11 kg ha-1 for each day of delay in the chicory transplant (0 to 42 days). The total and per harvest chicory yields were not influenced by its transplant time in relation to collard green transplant. The collard green and chicory intercropping provided 52% higher land use efficiency than their monocultures when the chicory was transplanted 42 days after collard green.

Heavy metal concentration in vegetables and their potential risk for human health

This study assesses heavy metal levels in the water, soil, and vegetables (swiss chard, lettuce, cabbage, collard green, tomato, green pepper, and carrot) irrigated with wastewater in Gamo, Ethiopia. The samples of soils, waters, and vegetables were randomly collected, processed, and analyzed for heavy metals using atomic absorption spectroscopy. The results obtained show that the mean concentrations of Cd, Cr, and Ni had the highest concentration, and Pb, Zn, and Cu had the lowest concentration in irrigation waters. The levels of Cd in the Kulfo river area and Chamo Lake area and Cu in most of the farm soils were also found to be higher than the guideline values. The study also revealed that the mean levels of Cd in most vegetables and Cr and Pb in some vegetables were higher than the maximum recommended limits set by the World Health Organization / Food and Agriculture Organization 2001. Among the vegetables, cabbage had the highest heavy metal content followed by Swiss-chard, carrot, tomato, collard green, green pepper, and lettuce. The Hazard quotient of Cu, and Ni of all samples of vegetables and Cd in some samples vegetables obtained exceeded unity. It signifies that there are potential health risks to the consumers. This study recommends regular monitoring of heavy metals in soils, waters, and foodstuffs to prevent excessive accrual in the food chain.

Heavy metal concentration in vegetables and their potential risk for human health

This study assesses heavy metal levels in the water, soil, and vegetables (swiss chard, lettuce, cabbage, collard green, tomato, green pepper, and carrot) irrigated with wastewater in Gamo, Ethiopia. The samples of soils, waters, and vegetables were randomly collected, processed, and analyzed for heavy metals using atomic absorption spectroscopy. The results obtained show that the mean concentrations of Cd, Cr, and Ni had the highest concentration, and Pb, Zn, and Cu had the lowest concentration in irrigation waters. The levels of Cd in the Kulfo river area and Chamo Lake area and Cu in most of the farm soils were also found to be higher than the guideline values. The study also revealed that the mean levels of Cd in most vegetables and Cr and Pb in some vegetables were higher than the maximum recommended limits set by the World Health Organization / Food and Agriculture Organization 2001. Among the vegetables, cabbage had the highest heavy metal content followed by Swiss-chard, carrot, tomato, collard green, green pepper, and lettuce. The Hazard quotient of Cu, and Ni of all samples of vegetables and Cd in some samples vegetables obtained exceeded unity. It signifies that there are potential health risks to the consumers. This study recommends regular monitoring of heavy metals in soils, waters, and foodstuffs to prevent excessive accrual in the food chain.

Antihyperglycemic Effect of the Moroccan Collard Green (Brassica oleracea var. viridis) in Streptozotocin-Induced Diabetic Rats

Aims: The aim of the study was to assess the antihyperglycemic activity of Brassica oleracea. Background: Collard green or Brassica oleracea var. viridis which belongs to Brassicaceae family is ranked at 10th place of “powerhouse” vegetables, and it is commonly used traditionally for the treatment of diabetes in Morocco. Objective: This current investigation aimed to assess the antihyperglycemic capacity of the aqueous extract of Collard green leaves. Methods: The effect of a single (6 hours) and repeated (seven days of treatment) oral administration of Collard green aqueous extract (CGAE) at a dose of 60 mg/kg on glucose and lipid profile was examined in normal and streptozotocin-induced diabetic rats. Additionally, histopathological examination of liver was carried out according to the Hematoxylin-Eosin method. Furthermore, a preliminary phytochemical screening, and the quantification of phenolic, flavonoid and tannins contents as well as the antioxidant activity using DPPH assay were carried out. Results: The results demonstrated that Collard green A.E. (CGAE) exhibited a significant antihyperglycemic effect and positive improvement liver histology in diabetic rats. After a single oral administration of CGAE, blood glucose levels were lowered from 15±2 mM to 4.9±1 mM (p<0.0001) at the sixth hour in diabetic rats but no change was observed in normal rats. Repeated CGAE administration was able to reduce blood glucose levels from 15±2 mM to normal values (5±1 mM at the seventh day, p<0.0001) while the extract had no effect in normal rats. In addition, we revealed that CGAE is rich in several phytochemical compounds and exerts an important antioxidant activity. Conclusion: In conclusion, this study demonstrates that Collard green possesses a beneficial effect against diabetes, and can be used in the program diet of diabetic patients.

Effects of Collard Green Consumption on the Human Plasma and Urine Metabolome: An Untargeted Analysis

Objectives Whereas phytochemicals derived from cruciferous vegetables have demonstrated health benefits, the data linking intake of these vegetables to health outcomes are inconsistent. These inconsistencies may stem from methodological limitations in accurately assessing cruciferous vegetable exposure. Goals of this study were to explore the use of endogenously deuterium-labeled collard greens combined with untargeted metabolomics to identify unique plant-derived and host-derived metabolites following vegetable consumption as potential biomarkers of cruciferous vegetable intake in humans. Methods 26 participants (16 women, 10 men) were fed a breakfast including 100 g of collard greens grown with or without deuterium-labeled water. Plasma was sampled prior to ingestion and 4 h post-ingestion; 24 h urine samples were also collected. High-pressure liquid chromatography Triple Q-ToF mass spectrometry-based untargeted metabolomics was performed. Results Analysis of collard greens confirmed deuterium-labeled compounds, including glucosinolates (glucobrassicin, sinigrin), and flavonols (quercetin). The maximum abundance of stable isotopologues was 2H4 (M4) for glucobrassicin and 2H12 (M12) for 1,2,2'-trisinapoylgentiobiose. Consumption of collard greens was associated with a significant increase in 199 compounds in plasma, including a 5.26-fold increase in the antioxidant hydroferulic acid (q &lt; 0.05). A significant decrease in 144 compounds in plasma was also found with collard green consumption. Likewise, a significant increase in 819 compounds and decrease in 1209 compounds was found in urine following collard green consumption. A deuterium labeled 18-carbon fatty acid was significantly increased in plasma, indicating it was derived from the collard greens. Work is ongoing to further identify deuterium-labeled plant derived compounds in human plasma and urine. Conclusions Consumption of a cruciferous vegetable changed the urine and plasma metabolome. Ongoing research is required to identify these metabolites in order to develop novel signatures of food intake. Funding Sources National Institutes of Health, United States Department of Agriculture Agricultural Research Service, National Institute of Food and Agriculture.

Collard green yield and nutritional quality with mineral and organic fertilization

A study was conducted to investigate the effect of organic and mineral fertilization on collard green yield, and to assess the macro and micronutrient and heavy metal concentrations of its leaves to assess the potential hazards of manure use. Collard plants (Brassica oleracea var. acephala, cv. couve-manteiga) were grown in 4-L pots filled with a clay soil under greenhouse conditions. The experimental design used was completely randomized design and the treatments in a 3 × 4 factorial arrangement: three N sources (pig slurry, poultry manure, and urea) and four N rates (0, 100, 200 and 300 mg kg-1), with four replicates. Collard greens leaves were harvested 70 days after seedling plantings. The manure application (pig slurry or poultry manure) resulted in collard yield equivalent to the application of mineral fertilizer. However, the pig slurry application resulted in an increase of leaf Fe, Mn, Zn, Cd, Cr, and Pb concentrations. Nitrogen application rates up to 300 mg N kg-1 result in the higher yield and nutritional quality of collard leaves. The application of high rates of manure, especially pig slurry, results in the increase of heavy metal (Cd, Cr, and Pb) concentrations. However, the maximum concentrations of 0.042 mg kg-1 Cd, 0.034 mg kg-1 Cr and 0.030 mg kg-1 Pb are well lower than maximum daily intake limit established by the Brazilian legislation, indicating that the consumption of collards from organic production systems with the manure application can be considered safe and without risk to human health.