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INTERNATIONAL JOURNAL OF CURRENT RESEARCH IN CHEMISTRY AND PHARMACEUTICAL SCIENCES NUTRITIVE VALUES,PHYTOCHEMICAL AND HEAVY METAL COMPOSITIONS OF GREEN LEAFY VEGETABLES: A REVIEW
Abstract
Green leafy vegetables occupy an important place among the food crop as they provide adequate amount of many vitamins and minerals like calcium, iron and phosphorous. Green leafy vegetables constitute an indispensable constituent of human diet. Dark green leafy vegetables are an excellent source of fiber, folate and carotenoids. These vegetables also contain vitamins C and K and the minerals iron and calcium. In addition, dark green leafy vegetables act as antioxidants in the body. The substances in dark green leafy vegetables remove free radicals from the body before they become harmful. There is evidence that the carotenoids found in dark green leafy vegetables can stop the growth of certain types of breast, skin, lungs and stomach cancer. Also foo ds containing folates reduces risk of pancreatic cancer while foods containing dietary fiber reduces risk of developing colorectal cancer. However, both vital and lethal elements are present in green leafy vegetables.
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The content of nickel (Ni), cadmium (Cd), chromium (Cr), lead (Pb) and copper (Cu) in five different types of green leafy vegetables viz., “Kangkung (Ipomoea aquatica), Mukunuwenna (Alternanthera sessilis), Thampala (Amaranthus viridis), Nivithi (Basella alba) and “Kohila” (Lasia spinosa) collected from four randomly selected urban and sub urban market sites in and around Piliyandala area of Colombo District, Sri Lanka, were measured using atomic absorption spectrometry. The results showed significant differences in elemental concentrations among the green leafy vegetables analyzed. The average concentrations of heavy metals detected in green leafy vegetables ranged from 0.71-15.89, 0.07-0.97, 0.18-5.05, 0.18-1.59, 7.05-18.44 mg/kg for Ni, Cd, Cr, Pb and Cu respectively, on dry matter basis. In addition, the mean concentrations of metals in the green leafy vegetables were found in the order of their abundance as Cu>Ni>Cr>Pb>Cd. However, there were no significant differences (p < 0.05) between the heavy metal contents in combined green leafy vegetables collected from the four market sites. It was also found that the Ni, Cd, Cr and Pb levels exceeded the maximum permissible limits set by FAO/WHO for human consumption.
The content of nickel (Ni), cadmium (Cd), chromium (Cr), lead (Pb) and copper (Cu) in five different types of green leafy vegetables viz., “Kangkung (Ipomoea aquatica), Mukunuwenna (Alternanthera sessilis), Thampala (Amaranthus viridis), Nivithi (Basella alba) and “Kohila” (Lasia spinosa) collected from four randomly selected urban and sub urban market sites in and around Piliyandala area of Colombo District, Sri Lanka, were measured using atomic absorption spectrometry. The results showed significant differences in elemental concentrations among the green leafy vegetables analyzed. The average concentrations of heavy metals detected in green leafy vegetables ranged from 0.71-15.89, 0.07-0.97, 0.18-5.05, 0.18-1.59, 7.05-18.44 mg/kg for Ni, Cd, Cr, Pb and Cu respectively, on dry matter basis. In addition, the mean concentrations of metals in the green leafy vegetables were found in the order of their abundance as Cu>Ni>Cr>Pb>Cd. However, there were no significant differences (p < 0.05) between the heavy metal contents in combined green leafy vegetables collected from the four market sites. It was also found that the Ni, Cd, Cr and Pb levels exceeded the maximum permissible limits set by FAO/WHO for human consumption.
The paper presents the results of a study on the heavy metals in some green leafy vegetables.The leafy vegetables were sampled from different areas of Sulaimani city. They were digested using three-acid mixture (68%HNO3, 98%H2SO4 and 37%HCL). Analyzing of the heavy metals was performed using atom absorption spectrophotometry. The concentrations (mg/kg) of heavy metals in samples were ranged from 6.118 to 339.646 for Fe , 0.041 to 0.247 for Cr , 0.000 to 0.027 for Cd, 0.196 to 0.301 for Cu, 0.037 to 0.503 for Ni and 0.690 to 2.016 for Zn. The highest concentration of heavy metals was for Pb in leek and Fe curly cress at the Garazel. The amount of Cu in mint, leek, dill and celery in the samples collected from wuluba farms was more than those collected in Garazel farms. In contrast, the amount of Ni in mint, leek, dill and celery for the sample collected from Garazel farms were more than those of Wuluba farms. Thus, the amount of Pb in dill, celery, curly cress and Cd in mint, leek, dill for the sample collected from Wuluba farm was more than those of Garazel farms. However, the amount of Zn in mint, celery and curly cress for the sample collected from Wuluba farm were more than those of Garazel farms. Also, the amount Fe in mint, dill, celery, curly cress and Cr in celery, curly cress in the sample collected from Garazel farm was found to be higher compared to those of Wuluba farms. It can be concluded from this investigation that the amount of Pb, Fe, Cr, Cd, Cu, Ni and Zn was lower than the acceptable level recommended by WHO, FAO.
Battery production is one of the main sources of heavy metals that present great harm to human health even in low concentrations. Chromium (Cr), Cadmium (Cd) and Lead (Pb) were measured in edible portions of vegetables and soils around a battery production area in China, and the potential health risk of heavy metal contamination to the local population via vegetable consumption was evaluated. Their concentrations in edible portions of vegetables were 2.354 (0.078-14.878), 0.035 (0.003-0.230) and 0.039 (0.003-0.178) mg kg-1, respectively. Approximately 3% of the Cd in the vegetable samples exceeded the maximum concentration allowable by national food safety criteria, although Pb content in all samples were within the criteria. Transfer factors (TF) from soils to vegetables were dependent on vegetable species. Leguminous vegetables were more likely to accumulate Cr, while leaf vegetables tended to show higher levels of concentration of Cd and Pb. Melon vegetables demonstrated a relatively low capacity for accumulating the heavy metals studied. TF were positively correlated with soil organic matter and negatively correlated with soil pH. The mean estimated daily intake of Cr, Cd and Pb via dietary consumption of vegetables was 0.011, 1.65 × 10-4 and 1.84 × 10-4 mg kg-1 of body weight per day, respectively, levels that were much lower than the reference doses recommended by USEPA (U.S. Environmental Protection Agency) and JECFA (Joint FAO/WHO Expert Committee on Food Additives), indicating that the potential health risk of Cr, Cd and Pb exposure via vegetable consumption to the local population around this battery production area could be negligible.
The effects of time and temperature variation on the levels of anti-nutrients in five popularly consumed green leafy vegetables in Akwa Ibom State, Nigeria, were investigated. The vegetables were obtained from Ikot Abasi, Akwa Ibom State in Nigeria, and they included Utazi leaf (Gongronema latifolium), Bitter leaf (Vernonia amygdalina), Curry leaf (Ocimum canum sims) Bush apple leaf (Heinsia crinata) and Waterleaf (Talinum triangulare). The vegetables were subjected to heating conditions of 50°C and 90°C for 5 minutes and 15 minutes, and the levels of selected anti-nutrients (phytate, cyanides, tannins, oxalates) assessed. Heating conditions reduced the levels of all the investigated anti-nutrients in vegetables in the studies; the greatest reduction in level was observed in oxalates. In the vegetables, Talinum triangulare recorded the greatest reduction in anti-nutrients levels, tannins (84.4%), phytates (84.1%), cyanides (35.8%), total oxalate (57.1%) and soluble oxalate (75%). Heating at 90°C for 15 minutes was the most impacting for all the vegetables. The reduction of tannins ranged from 25.4 to 84.4%, phytates from 43.7 to 84.1%, cyanides from 22.1 to 40.7%, total oxalates from 57.1 to 75.0%, soluble oxalates from 66.7 to 78.3%. This study reveals that the most effective thermal processing temperature and time for anti-nutrient reduction in the selected vegetables was 90oC for 15 minutes. The data generated will help dieticians and other health workers in the formulation of different diets to meet the varied needs of patients in clinics and health establishments.
Two non-conventional leafy vegetables namely Hibiscus cannabinus and Haematostaphis barteri consumed largely by the rural dwellers in Adamawa State of Nigeria were subjected to standard chemical analysis to determine proximate nutrient content, amino acid composition and anti-nutritional factors. The results of the proximate analysis showed high crude fibre in H. barteri (33.04%), H. cannabinus had percentage crude fibre (29.61%). The protein contents were relatively high in both vegetables (13.78 and 12.40%), respectively. Carbohydrate, lipid, ash and moisture contents were within the range of values expected for dry leafy vegetables. All the essential amino acids were present in good quantities in both vegetables. Only cysteine and methionine ranked below 50% in comparison to the WHO/ FAO reference protein. The anti-nutritional factors analysed in the vegetables namely, tannins, oxalates, and phytates were lower than the range of values reported for most vegetables.
Human exposure to heavy metals is a subject of public health concern that have attracted the attention of researchers, health and nutrition experts all over the world. Green Leafy Vegetables (GLVs) are important part of diets in the South-South Region of Nigeria. Consumption of vegetables exposed to heavy metals contamination may lead to serious health complications. In this investigation, we estimated the concentrations of some heavy metals (Pb, Hg, Al, Cd, Fe and Zn) in GLVs harvested from vegetable gardens in the residential areas along Itam road construction site, Uyo, Nigeria. The results showed that Pb, Hg, Al and Cd concentrations were significantly high (p<0.05) in all exposed GLV samples than the control but Teliferia occidentalis had higher values of heavy metals than Talinium triangulare. However, zinc and iron levels in the GLV exposed samples were not significantly (p>0.05) higher than the control. Our findings showed that heavy metal contamination of edible vegetable is high at road construction sites and may impact negatively on the health of human and animals living in such environment. We suggest that health impact assessment be carried out at construction sites in order to suggest necessary measure that can alleviate the effects of such environmental contaminants.
The concentrations of heavy metals in different food web components, such as zooplank-ton, benthic invertebrates and fish, were examined in small humic lakes from southern Finland. Variation in metal concentrations in zooplankton was observed between different lakes and in benthic invertebrates between different animal groups. We found a significant relationship between lakewater pH and Cd concentration in isopods (Asellus aquaticus), while no relationship between the humic content of lakewater and Cd or Hg concentrations was observed. Annual variation in Cd, studied over a six-year period, was correlated with the amount of discharge, which indicated the importance of the annual loading of Cd from the catchment in determining accumulation in isopods. The metal concentrations in perch (Perca fluviatilis) were higher in a humic and acid lake than in a slightly humic lake and may partly be explained by the varying dietary regime of perch.
Compounds or substances which act to reduce nutrient intake, digestion, absorption and utilization and may produce other adverse effects are referred to as antinutrients or antinutritional factors. Seeds of legumes and other plant sources contain in their raw state wide varieties of antinutrients which are potentially toxic. The major antinutrients includes: toxic amino acids, saponins, cyanogenic glycosides, tannins, phytic acid, gossypol, oxalates, goitrogens, lectins (phytohaemagglutinins), protease inhibitors, chlorogenic acid and amylase inhibitors. These antinutrients pose a major constraint in the use of plant protein sources in livestock feeds without adequate and effective processing. The level or concentration of these anitnutrients in plant protein sources vary with the species of plant, cultivar and post-harvest treatments (processing methods). This paper reviews the nutritional effect of major antinutrients present in plant protein sources.
Problem section: Effluents from the surrounding industries such as tannery and textile are used by vegetable farmers for the irrigation of their crops. These effluents may contain some toxic metals which bioaccumulate along the food chain. Moreover the uptake of such toxic metals by crops is governed by their availability and concentration in the soil. Therefore such crops may accumulate heavy metals in excessive amount in their various parts. This may ultimately, adversely affect humans and other species that depend on such crops for food, hence the need to evaluate the pollutant levels in vegetables samples in these areas. Approach: Six vegetable samples of various organs were freshly harvested from ten farms within the vicinity of Challawa industrial areas. The concentration of heavy metals which include, Cu, Zn, Co, Mn, Mg, Fe, Cr, Cd As, Ni and Pb, were determined using Perkin-Elmer analyst 300 Atomic Absorption Spectroscopy (AAS). Levels of some anions (nitrate, nitrite, sulphate and phosphate were determined using Hach direct reading 2000 Spectrophotometer. Results: The results obtained from this analysis revealed that Cr and Fe shows the highest concentrations, while As shows the lowest levels in the whole vegetable organs studied. The concentrations of the anions ranged between 40.00-1300.00 µg g1 nitrite, 65-1500 µg g1 nitrate, 122.00-765.00µg g1 and 12.00-60.00 µg g1. The leaves contained much higher concentrations of heavy metals and anions than roots and stems. Conclusions: The concentrations of the above parameters were higher than the FAO, WHO/EU and FAO/WHO allowed limit. The high values might be attributed to the used of untreated effluents from textile and tanneries industries by farmers for the irrigation of these vegetables. Thus, the high values of these trace metals and anions in the vegetable samples could put the consumers of these vegetables at health risk. Further works should be carried out in the soil samples were the vegetables are grown.
Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity.
Metal ions contamination may inhibit microorganisms involved in the biodegradation of organic compounds and affect biodegradation rates. Therefore, it is likely that bioremediation of xenobiotics-contaminated soils and waste will require inoculation with efficient biodegrading microbial communities, with capabilities of being resistant to heavy metals as well. Two different transconjugants (Pseudomonas sp. KM12TC and P aeruginosa TC) were constructed by conjugation experiments. Results on MIC, induction and growth inhibition strongly indicated that arsenic-resistant plasmid, pKM20, could be mobilized, and the newly acquired phenotype of pKM20 was not only expressed but also well regulated, resulting in newly acquired resistances to As5+, As3+, and Sb3+ in addition to Cd2+, Zn2+, and Hg2+. The phenol-degradation efficiencies of Pseudomonas sp. KM12TC were maintained significantly even at high heavy metal concentrations at which these efficiencies of P. aeruginosa TC were completely impaired. The results in this study on the effects of heavy metals on phenol degradation, especially after conjugation, are the first ever reported. All the results described in this study encourage to establish a goal of making "designer biocatalysts" which could degrade certain xenobiotics in the area contaminated with multiple heavy metals.
No published data are available on heavy metals concentrations and contaminations of vegetables in Huanggang City, Hubei Province, China. This study focused on characteristics and evaluation on heavy metal (Copper and Cadmium) concentrations and contaminations in vegetables grown in the suburbs of Huanggang. Several important vegetable bases in the suburbs of the city were employed as study areas and 150 representative vegetable samples, including leaf vegetables, melon-fruit vegetables, root-stem vegetables, bean vegetables and melon-fruit vegetables, were collected to determine the contents of heavy metal Copper (Cu) and Cadmium (Cd) using Atomic Absorption Spectrophotometer (Varian, AA240FS, USA). The status of Cu and Cd concentrations and contaminations were analyzed and evaluated according to Chinese Food and Health National Standard. The results indicated that nearly all vegetable in Huanggang City were highly contaminated by Cd. And Cu contamination occurred in leafy vegetables and some melon-fruit vegetables and bean vegetables were not found contaminated by Cu. The contamination degree of Cd was much higher than that of Cu. Vegetable Cd contamination has posed a threat to the people in the city and will hinder the sustainable development of the local vegetable industry. It is strongly recommended that the local government of Huanggang City should pay much more attention to the vegetable Cd contamination in the city. Why heavy metal Cd polluted seriously and how to prevent it in the city need to be further studied.
Heavy metal levels in sixteen different fruits and leafy vegetables from selected markets in Lagos,
Nigeria were determined using atomic absorption spectrometry. The results showed that the levels of
Lead, Cadmium, Copper, Zinc, Cobalt and Nickel ranged from 0.072±0.06 to 0.128±0.03; 0.003±0.01 to
0.005±0.01; 0.002±0.00 to 0.015±0.02; 0.039±0.01 to 0.082±0.01; 0.014±0.01 to 0.026±0.01 and 0.070±0.07
to 0.137±0.05 mg/kg, respectively, for the fruits. The levels of Lead, Cadmium, Copper, Zinc, Cobalt and
Nickel for the leafy vegetables respectively ranged from 0.09±0.01 to 0.21±0.06; 0.03±0.01 to 0.09±0.00;
0.02±0.00 to 0.07±0.00; 0.01±0.00 to 0.10±0.00; 0.02±0.00 to 0.36±0.00 and 0.05±0.04 to 0.24±0.01 mg/kg.
Values obtained are comparable with those available in the literature and within tolerable limits of some
regulatory authorities.
Anti-nutritional factors (ANF) are compounds which reduce the nutrient utilization and/or food intake of plants or plant products used as human foods or animal feeds and they play a vital role in determining the use of plants for humans and animals. Apart from cyanogenic glycosides, food poisoning arising from anti-nutritional factors, otherwise known as plants' secondary metabolites has not been properly addressed in most parts of the developing world. People have died out of ignorance, poverty and inadequate nutrition information and education, especially within the African societies. There are reports from time to time of deaths after consumption of some type of beans despite cooking. Also, cases of renal and liver diseases are increasing and this calls for a need to properly address the issue of thorough and adequate processing of foods/feeds before consumption. The aim of this review is to emphasize on the adequate processing of foods/feeds and to educate the people on the dangers of consuming improperly processed foods especially legumes which are reported to contain very high concentrations of anti-nutritional factors.
100 g, respectively. The mineral contents were; sodium 4.44±0.22-5.24±0.21 ug/g, calcium 1.07±0.22-4.82±0.14, potassium 0.97±0.06-0.98±0.05, magnesium 1.45±0.15, -1.95±0.16 ug/g, iron 0.09±0.01-0.61±0.02 ug/g, zinc ND-0.09±0.002 ug/g, phosphorus 0.89±0.05-2.82±0.07 ug/g and copper ND-0.24±0.01 ug/g. The antinutrient compositions were oxalate 0.88±0.12-2.20±0.25 ug/g, phytate 6.89±0.25-13.00±0.45 ug/g and hydrocyanide 0.13±0.04-0.23±0.01 ug/g. These results showed that these vegetables contained an appreciable amount of nutrients, mineral elements and low levels of anti-nutrients and could be included in diets to supplement our daily allowance needed by the body.
Six essential elements, cadmium and lead were determined in some horticultural species cultivated in greenhouse borders by atomic absorption spectrophotometry to evaluate the contribution of these vegetables to the daily intake of cadmium and lead in Spain. The existence of significant differences (P <0.001) in the levels of metallic concentration found among the vegetable species has been proved, and the greater capacity of concentration of heavy metals, except copper, in green beans was observed. No statistically significant correlation (P > 0.05) between the concentration of the soil and that of corresponding vegetable species was found. The heavy metal uptake from soil to plants is a function of the physical and chemical nature of the soil and is altered by innumerable environmental and human factors. If the mean levels of cadmium and lead (0.029 mg kg−1 and 0.221 mg kg−1 respectively) are taken into account, the daily intake contribution of these metals will be 1.4 μg day−1 for cadmium and 11 μg day−1 for lead.
The environmental exposure to heavy metals is a well-known risk factor for cancer. We investigated levels of seven different heavy metals, (Co, Cd, Pb, Zn, Mn, Ni and Cu) in soil, fruit and vegetable samples of Van region in Eastern Turkey where upper gastrointestinal (GI) cancers are endemic. Heavy metal contents of the samples were determined by flame atomic absorption spectrometer. Four heavy metals (Cd, Pb, Cu and Co) were present in 2- to 50-fold higher concentrations whereas zinc levels were present in 40-fold lower concentrations in soil. The fruit and vegetable samples were found to contain 3.5- to 340-fold higher amounts of the six heavy metals (Co, Cd, Pb, Mn, Ni and Cu) tested. The volcanic soil, fruit and vegetable samples contain potentially carcinogenic heavy metals in such a high levels that these elements could be related to the high prevalence of upper GI cancer rates in Van region.
Levels of some nutrients and antinutrients of six green leafy vegetables grown in SouthEast, Nigeria were determined using standard analytical methods Crude protein, fat, moisture, crude fiber carbohydrate and calorific values ranged from 1.20 to 2.20 g/100g, 0.80 to 1.30g/100g, 74 to 93%, 0.70 to 2.10 g/100g, 1.30 to 13.20g/100g and 21.00 to 97.00 kcal /100g. The vitamin C composition varied from 14.61 to 30.84mg. The elemental analysis of the six leaves in mg dry matter indicated that the leaves contained appreciable levels of iron (3.43 to 23.03), calcium (204.26 to 305.51 and magnesium (195.57 to 340.39). The antinutrient composition for phytic acid, tannins and oxalic acid are; 34.70 to 68.50mg/100g, 0.32to 0.83 g/100g and 24.65to 42.15 mg/g respectively. These results reveal that those leaves contain an appreciable amount of nutrient, vitamin, mineral elements and low level of toxicants and should be included in diets to supplement our daily allowance needed by the body.
Three tropical vegetable species (Talium triangulare, Amaranthus cruentus and Telfairia occidentalis) were selected based on their availability and agronomic desirability. The freshly harvested vegetable leaves were subjected to 2 processing techniques (shredding and sundrying) before milling into the vegetable leaf meals (VLMs). The crude protein ranged from 19.9+1.8 to 35.1+1.7. The crude fibre ranged from 8.8+3.1 to 12.7+4.2. Ether extract (fat) had a wide range of 5.4+3.2 to 29.2+2.1. Ash contents had a range of 10.9+6.2 to 19.4+3.0. The nitrogen free extract ranged from 19.7+0.3 to as high as 43.5+0.7. Gross energy values had a range of 251.5MJKg-1 to 383.2MJKg-1. The mineral contents of the air-dried VLMs indicated that Ca, Mg, Na, K are the most abundant minerals with values as high as 2.0, 2.5, 7.1 and 4.8gkg-1DM for Ca, Mg, Na and K respectively in some samples analysed. The amino acid profiles of the VLMs indicated favourable nutritional balance except for lysine and methinone which appear marginal. The Water Absorption Capacity (WAC), Fat Absorption Capacity (FAC), Fat Emulsion Capacity (FEC) and Emulsion Stability (ES) were similar for the 3 VLMs. The values obtained for Foaming Capacity, Least Gelation Concentration and Foaming Stability after 30 minutes for the 3 VLMs were also similar. The protein solubility curves of all VLMs were similar at both alkaline and acid media with minimum solubility (isoelectric point) at between pH 4 and 5 for the VLMs.
The study on the chemical composition of the seeds of one of the most popularly known and popularly consumed tropical plant, Gnetum africana (afang) has been carried out by analyzing samples of the plant seeds collected from some plantations located within Akwa Ibom State (South Eastern Nigeria) for chemical Composition. The proximate, elemental and toxicant composition of the seeds (Gnetum africana) were determined by analyzing samples of the identified seeds for their carbohydrate, protein, lipid, ash, fibre, moisture and caloric value (proximate composition), iron, zinc, lead, potassium, sodium, magnesium and calcium (mineral compositon) and tannin, hydrocyanic acid, oxalate and phytic acid (toxicant composition) using recommended method of analysis. The result of the analysis shows that the percentage moisture content, crude protein, crude fat, crude fibre, ash content and carbohydrate of this seeds are 31.60%, 17.50%, 3.15%, 0.80%, 1.20% and 87.62% respectively while its caloric value is 448.83kcal/100g. The percentage sodium, potassium, calcium, magnesium, iron, zinc and lead content of the seed were 15.57, 38.56, 7.01, 5.48, 1.50, 1.50, 1.07 and 0.03 respectively while its toxicant content were 540mg/100g, 100.74mg/100g, 209.00mg/100g and 238.26mg/100g for hydrocyanic acid, tannin, oxalate and phytic acid respectively. The proximate, mineral and toxicant composition of the seeds were also compare with values reported in literature for other edible vegetable and the results show that the seeds are poor source of essential elements compared with other vegetable seeds. The antinutritional content of the seeds were very high when compare to values reported for other vegetables. Based on the result of the present study, it has been found that afang seeds are rich in proximate composition (when compare with other edible vegetables). Their low mineral content and their high toxicant content therefore suggest that these seeds should be properly processed before consuming them and its consumption should be supplemented with other food whose elemental content are high.
Vegetables (Beta vulgaris L., Abelmoschus esculentus L. and Brassica oleracea L.) from the production and market sites of India were tested for Cu, Cd, Zn and Pb. At market sites, the mean concentration of Cu in cauliflower, and of Zn and Cd in both palak and cauliflower had exceeded the PFA standard. Zn at the production sites also exceeded the PFA standard in cauliflower. Cd concentration in vegetables tested from both production and market sites was many folds higher than the EU standard. In contrast, Pb in vegetables tested from both production and market sites was below the PFA limit, but was considerably higher than the current EU and WHO standards. Heavy metals accumulation in vegetables tested are higher at market sites than those at the crop production sites. The contributions of these vegetables to dietary intake of Cu, Zn, Cd and Pb were 13%, 1%, 47% and 9% of provisional tolerable daily intake, respectively. The study concludes that the transportation and marketing systems of vegetables play a significant role in elevating the contaminant levels of heavy metals which may pose a threat to the quality of the vegetables with consequences for the health of the consumers of locally produced foodstuffs.
The influence of the steelworks in Warsaw and Krakow as well as the zinc smelters in Bukowno and Miasteczko Slaskie on lead, cadmium, zinc and iron concentrations and the structure of selected tissues of yellow-necked mice were analysed. The Borecka Forest was chosen as a control area. The highest concentrations of lead, 172.36 g/g dry weight, and cadmium, 23.58 g/g, were detected in the femurs and kidneys, respectively, of rodents caught in Bukowno. Zinc and iron concentrations ranged over physiological values. No histopathological changes were observed in analysed tissues of all rodents in the control area. Damage occurred in the liver and kidneys of animals from all other sites and in the testes of rodents from Bukowno. Decreased glycogen content, interstitial fibrosis, and increased number of pyknotic nuclei as well as necrosis were seen in hepatocytes. In the kidneys hyperplasia of the tubules, atrophy of glomeruli, interstitial fibrosis and necrosis were observed. Degenerate cells were present in the lumen of seminiferous tubules of animals from the Bukowno area. Even relatively low concentrations of lead and cadmium, like those found in the liver and kidneys of rodents from the neighbourhood of the steelworks, caused histopathological changes.
Metal Concentrations In Four Leafy Vegetables Sold In Markets Of Abraka
- O M Agbogidi
- H A Erhenhi
Agbogidi, O.M and Erhenhi, H.A. (2013) Metal
Concentrations In Four Leafy Vegetables Sold In
Markets Of Abraka, Delta State, Nigeria. Journal
Biol.Chem. Research, 30 (2) 813-822.
Proximate Analysis of some Leafy Vegetables
- H M Aliyu
Aliyu, H.M. (2006) Proximate Analysis of some Leafy
Vegetables.
International Journal Foods Agric.
Resources 3(1):11-14.
Food of Plant Origin. 1 st Edition Adro Obis Publication Limited
- N J Enwere
Enwere, N.J. (1998) Food of Plant Origin. 1
st Edition
Adro Obis Publication Limited, Nsukka, Nigeria.
Anti-Nutritional Factors, The Potential Risks Of Toxicity And Methods To Alleviate Them
- R Kumar
Kumar, R. (1992). Anti-Nutritional Factors, The Potential
Risks Of Toxicity And Methods To Alleviate Them. In:
Speedy, A. and Pugliese, P. (Eds.), Legume Trees
And Other Fodder Trees as Protein Sources For
Livestock. Food and Agriculture Organization of the
United Nations (FAO), Kuala Lumpur. 145-157.
A (2014) Assessment Of Metal Content In Leafy Vegetables Sold In Market Of Libreville
- A A Mebale
- R O Ndon
- A L Affine
- H M Omanda
- P P Nziengu
- R M Biyoyo
- J Ondo
Mebale, A.A, Ndon, R.O, Affine, A.L.N, Omanda, H.M,
Nziengu, P.P., Biyoyo, R.M. And Ondo, J.A (2014)
Assessment Of Metal Content In Leafy Vegetables
Sold In Market Of Libreville, Garbon. Int. Journal Cur.
Res. Rev. 06(01) 28-33.2014.
Nutritional Quality of Food
- A U Osagie
- U E Offiong
Osagie, A.U. and Offiong, U.E. (1998) Nutritional Quality
of Food. A milk Press, Post Harvest
Research
Unit. University of Benin, Benin City, Nigeria.
How can the risk be reduced? Awake (December)
- Watchtower Bible
- Tract Society
Watchtower Bible and Tract Society. (1996). How can
the risk be reduced? Awake (December). New York
Inc. Pp4-8.