Aditives and Contaminants in Food

There are low toxicity substances and others that involve
risks for human health. For this reason, governments all
over the world have enforced specific legislation.
Pesticides, also called agrochemicals or plant protection products, are compounds
that are applied to crops to protect them from pests and diseases and increase yields. Among
them, there are low toxicity substances and others –that in certain concentrations- have
carcinogenic risks or may cause endocrine disorders. For this reason, governments around
the world have developed specific legislation.

The present review aims to describe the recent and most impactful applications in pollutant analysis using solid-phase microextraction (SPME) technology in environmental, food, and bio-clinical analysis. The covered papers were published in the last 5 years (2014-2019) thus providing the reader with information about the current state-of-the-art and the future potential directions of the research in pollutant monitoring using SPME. To this end, we revised the studies focused on the investigation of persistent organic pollutants (POPs), pesticides, and emerging pollutants (EPs) including personal care products (PPCPs), in different environmental, food, and bio-clinical matrices. We especially emphasized the role that SPME is having in contaminant surveys following the path that goes from the environment to humans passing through the food web. Besides, this review covers the last technological developments encompassing the use of novel extraction coatings (e.g., metal-organic frameworks, covalent organic frameworks, PDMS-overcoated fiber), geometries (e.g., Arrow-SPME, multiple monolithic fiber-SPME), approaches (e.g., vacuum and cold fiber SPME), and on-site devices. The applications of SPME hyphenated with ambient mass spectrometry have also been described.

Microplastic presence in seafood and foodstuff have been documented globally in recent studies. Consequently , human exposure to microplastics through the ingestion of contaminated food is inevitable and pose a risk to food security and human health. In this review, microplastics and related xenobiotics are defined, global evidence of microplastic pollution in seafood is reviewed, the impacts to commercial marine species and food security are discussed, and the current knowledge of its direct effects on human health is reviewed. In addition, limited information regarding food security and scientific gaps are identified. Although microplastics in the marine environment and its effects on marine organisms have been well documented, more research is needed to completely understand the implications of microplastics over food security and human health. Further research must focus on monitoring and eliminating microplastics along the food supply chain and determining the extent to which food security is affected by microplastic pollution.

The role of physics in biological sciences has not been neglected but recently it grew due to the rising problems with food quality and its control. A short review of the substitute of chemical fertilizers and plant protection products with treatment with physical factor, as a means of providing clean row materials, is presented. The use of electromagnetic fields (magnetic, microwave, electric field) is mentioned and the ultrasonic treatment as well. Physical methods for food control also contribute for raising the role of physics. The use of electromagnetic and optical techniques and in particular fluorescence spectroscopy for food quality control is shortly described as well. This relatively new method is used to reveal adulteration in honey, composition of sunflower, pumpkin and melon oils, as well as some wild fruits.

Lateral flow tests, also known as immune chromatographic strip (ICS) tests, are point of care tests that have reduced the time spent waiting for test results from hours to minutes utilizing immunochromatographic assy. It requires no specialized equipment, less technical training for
operators and has reduced the cost of device development as well as care. Recent progress in the laboratory has been a result of improvements in rapid analytical techniques. An update of the applications for lateral flow tests (also called immunochromatographic assay or test strip) is presented
in this review manuscript. The paper reviews the current trend of investigation on technology in the detection of a variety of food contaminants, residues, and chemical constituents. It includes
outstanding data, such as sample treatment, sensitivity, specificity, accuracy and reproducibility. Lateral flow tests provide advantages on simplicity and rapidity when compared to the conventional detection methods and interact with his foreign customers and clients across geographical boundaries
while socially and culturally connecting their significant on-work and off-work people.

Usted ha sido contratado en una fábrica de embutidos para realizar una etiqueta de un nuevo producto. En ella debe indicar los aditivos alimentarios que va a utilizar y explicar el porqué de su elección. El nuevo producto a elaborar es salchichón cervecero. Los ingredientes a emplear son los siguientes: Chorizo El chorizo es un producto cárnico rico en grasa, que le confiere unas propiedades organolépticas excepcionales y de gran aceptación por todo tipo de consumidores. La siguiente es una formulación del chorizo MATERIA PRIMA Carne de cerdo – Brazo o paleta sin grasa = 70% (95:5)-95% de carne magra-5% de grasa Tocino de cerdo (sin piel) = 25% Agua potable fría = 5% Condimentos y aditivos SAL = 1.8% del total de la carne y grasa SAL DE CURA = 5 gramos por kilo de sal CEBOLLA LARGA = 20 gramos por kilo de carne y grasa AZUCAR = 15 Gramos por kilo de sal AJO = 5 Gramos por kilo de carne y grasa PÁPRIKA = 3 Gramos por kilo de carne y grasa PIMIENTA NEGRA = 2 Gramos por kilo de carne y grasa COMINO = 2 Gramos por kilo de carne y grasa ORÉGANO = 2 gramos por kilo de carne y grasa Nitratos y Nitritos

The presence of 3-monochloropropanediol (3-MCPD) in edible oils has been widely reported with its potential health risks. The aim of this study was to apply optimized recent updated and validated enhanced swift analytical indirect method for determining 3-MCPD in consumed edible oils (palm, palm olein, extra virgin olive, corn, sunflower, soybean, olive pomace) and blend of 5% sunflower oil with extra virgin olive oil, using selective and sensitive gas chromatography tandem triple quadrupole mass spectrometry (GC-MS/MS) employing deuterated 3-MCPD (3-MCPD-d5) as internal standard (IS) during the entire analytical procedure to obtain precise and accurate results. The occurrence and variation of 3-MCPD contents among the studied oils were found in different levels ranged from 93.1 µg/kg to 5634.1 µg/kg oil samples, with maximum value assigned for palm oil (5634.1 µg/kg) followed by palm olein (5576.8 µg/kg), corn oil (2447 µg/kg), sunflower oil (1817.3 µg/kg), soybean oil (1486.1 µg/k...

For the published version of this paper, see: https://www.academia.edu/16302941/The_Spectacular_Origins_of_the_EU_Horse_Meat_Scandal

We are currently faced with a scale of industrial food production that has reached inhuman proportions; even our mediated forms of oversight (e.g. quality control, food inspection, sensor technologies) cannot fully capture all the movements of inputs and outputs across the globe. The 2013 horse meat scandal in Europe made this very clear. Nearly 200 beef products sold in the EU were found to contain horse meat, but the scale of the supply chain made investigating the source of the ‘contamination’ extremely challenging. The proportions in which meat is produced—disassembled and ground up, distributed, and reassembled from thousands of animals—allowed the horse meat to mingle with beef unnoticed. Only DNA testing could sort one being from the other.

Using the theory of Guy Debord, this paper will focus on food packaging, arguing that it is less about informing the consumer than it is a spectacle, as well as the opacity of the supply chain and the contribution of each to the horse meat scandal. While the spectacle belongs to the realm of sight, its reach goes much further. That is why the horse meat scandal is striking: it allows us to see a rift in the spectacular veil of commodity production but also to acknowledge how its effects extend to the body. As I will outline in my exposition of the scandal’s timeline and initial outcome, one of the first considerations when news of the adulteration reached government officials was whether it was one of fraud alone or a risk to human health as well. In this instance, it was judged that it was an example of food crime, and that only the sensibilities of the public had been offended. But there is yet a darker lining to this story, when if something so seemingly substantial as horse flesh can mix imperceptibly with beef flesh, then one can only imagine what other invisibles could pass through the supply chain and into our bodies unnoticed.

Microbiological methods are not commonly used to inspect the hygienic status of butcher shops. Therefore, the study was intended to identify and assess the bacterial quality of meat contact tables in 100 randomly selected meat shops in Zaria, Nigeria. A total of 100 swab samples were obtained from the butchers' processing tables. The swab samples were inoculated on plate count agar for enumeration of bacterial load and on different selective media to isolate pathogenic bacteria. Out of the 100 swab samples, averages of 25 were collected from tables in each of the four different zones within Zaria metropolis. The isolates were characterized biochemically and subjected to antibiotic sensitivity test. The mean bacterial count (log10cfu/cm 2) was found to be 5.10, 4.00, 5.80 and 6.60 from zones 1, 2, 3 and 4, respectively. Whereas the result for Mean total coliform count was 4.00, 2.50, 3.70 and 2.80 from tables located in zones 1, 2, 3 and 4 respectively. E. coli was the predominant isolate (27.10%) followed by Salmonella typhi (15.89%). The least bacterial isolate was Pseudomonas aeruginosa with frequency of 5.61%. Antibiotic susceptibility study showed that the isolates were multidrug resistant though all antibiotics tested were active against some strains of the isolated organisms but all isolates were resistant to ampicillin. The results obtained in this study indicate that there was a poor level of personnel hygiene and poor sanitation at the butcher shops thus there is need to educate butchers and meat handlers of the importance of practicing good sanitation and meat handling techniques.

Este trabajo pretende analizar el modo en que la normativa internacional de agencias globales como la FAO, la OMC y la OMS limita y condiciona las posibilidades de una construcción autónoma de la regulación regional sobre alimentos. Esto se muestra a partir del análisis de un caso: el proceso de autorización de los aditivos alimentarios en el Mercosur. En primer lugar, se mapea brevemente la regulación alimentaria a nivel global, ante todo los Acuerdos de la OMC en la materia y las normas del CODEX ALIMENTARIUS (FAO/OMS). Se trata de mostrar su influencia en la armonización legislativa alimentaria en la región del Mercosur que tiene lugar a través de las resoluciones del Grupo Mercado Común (GMC). Segundo, se explica el caso analizado (la autorización de los aditivos alimentarios) describiendo el modo en que la normativa regional genera un efecto de alineamiento en función de estándares producidos al exterior de la región. Sin embargo, esta normativa trae una excepción a la regla de...

Nuclear magnetic resonance spectroscopy is introduced for the analysis of alcoholic beverages in the context of governmental health and safety control. For sample preparation of all types of alcoholic beverages, only addition of buffer is required as single step. To detect potentially unsafe samples especially in the context of unrecorded alcohol (i.e., illegally or informally produced alcohol), a
nontargeted approach based on principal component analysis (PCA) was applied. The PCA scores plot of 304 samples clearly shows seven conspicuous samples with highly divergent scores from the rest of the samples. These samples contained hazardous substances such as diethyl phthalate or polyhexamethyleneguanidine, as well as extremely high concentrations of methanol or ethyl carbamate. In addition to the nontargeted approach, partial least squares regression allowed us to quantify several parameters such as methanol, higher alcohols, 2-phenyl alcohol and ethyl acetate with high correlation to gas chromatographic reference analysis (R2 = 0.92-0.98).

Foams and Biliquid Foams -Aphrons in 1987, consist of a system of spherical microbubbles with diameters mostly above 25 µm and classified as kugelschaums (ball foam). They possess some colloidal properties and can be pumped at uniform rate through pipes and channels, much like liquids. Also, they have high stability due to very small size and thick surfactant shells. Research work published over the past two decades indicate effective applications of CGAs for clarification of particles and microorganisms, protein separation, gas and nutrient transfer and pollutant separation from water and soil matrices. In this review paper, the techniques for generating CGAs and their application to pollution abatement are discussed. Some mineral separation processes by CGA flotation have also been reviewed because of their relevance to contaminant removal processes. The CGAs were found to function on the principles of bubble entrained floc flotation, electrostatic and ionic interaction, diffusion of entrapped gas and hydrophobicity of the pollutant particles. Two tables have also been provided to present a comparative overview of the generation technologies and the effectiveness of pollution remediation techniques.

Aims: The consumption of alcoholic beverages has been identified as carcinogenic by the International Agency
for Research on Cancer. We aim to summarize the evidence on acetaldehydeas the main mechanism underlying
this relation, because humans are exposed to acetaldehyde both through ingestion of acetaldehyde present in alcoholic
beverages and acetaldehyde produced through ethanol metabolism. Methods: A literature review of alcohol,
acetaldehyde and cancer was used as input for a risk assessment for acetaldehyde derived from alcohol consumption for Germany. Results: There is increasing
evidence that acetaldehyde is carcinogenic. Risk assessment scenarios were below the 1:10,000 lifetime risk for cancer threshold (average scenario 8/10,000; extreme scenario 4/1,000), which is considered public health relevant.
Conclusion: Acetaldehyde exposure from alcohol alone warrants interventions based on the precautionary principle of public health. It is recommended that high alcohol consumption should be reduced and acetaldehyde levels in alcoholic beverages should be reduced as low as technologically possible, along with the implementation of
maximum limits.

3-Monochlor-1,2-propandiol (3-MCPD) ist seit 1978 als Lebensmittelkontaminante in Sojasoßen und Eiweißhydrolysaten bekannt. Toxikologische Studien zeigten die kanzerogene Wirkung von 3-MCPD in Ratten sowie die genotoxische Aktivität in vitro.

Colloidal gas aphrons (CGAs), first described by Felix Sebba in his book Foams and Biliquid Foams-Aphrons in 1987, consist of a system of spherical microbubbles with diameters mostly above 25 μm and classified as kugelschaums (ball foam). They possess some colloidal properties and can be pumped at uniform rate through pipes and channels, much like liquids. Also, they have high stability due to very small size and thick surfactant shells. Research work published over the past two decades indicate effective applications of CGAs for clarification of particles and microorganisms, protein separation, gas and nutrient transfer and pollutant separation from water and soil matrices. In this review paper, the techniques for generating CGAs and their application to pollution abatement are discussed. Some mineral separation processes by CGA flotation have also been reviewed because of their relevance to contaminant removal processes. The CGAs were found to function on the principles of bubble entrained floc flotation, electrostatic and ionic interaction, diffusion of entrapped gas and hydrophobicity of the pollutant particles. Two tables have also been provided to present a comparative overview of the generation technologies and the effectiveness of pollution remediation techniques. © 2012 Society of Chemical Industry.

http://onlinelibrary.wiley.com/doi/10.1002/jctb.3691/full

Este trabajo pretende analizar el modo en que la normativa internacional de agencias globales como FAO, OMC y OMS, limita y condiciona las posibilidades de una construcción autónoma de la regulación regional sobre alimentos. Esto se muestra a partir del análisis de un caso: el proceso de autorización de los aditivos alimentarios en el Mercosur. En primer lugar, se mapea brevemente la regulación alimentaria a nivel global, centralmente los Acuerdos de la OMC en la materia y las normas del Codex Alimentarius (FAO/OMS). Se trata de mostrar su influencia en la armonización legislativa alimentaria en la región del Mercosur que tiene lugar a través de las Resoluciones del Grupo Mercado Común (GMC). Segundo, se explica el caso analizado (la autorización de los aditivos alimentarios) describiendo el modo en que la normativa regional genera un efecto de alineamientos tras estándares producidos externamente a la región. Sin embargo, esta normativa trae una excepción a la regla de alineamiento general (las especies botánicas de origen regional) que nos permite vislumbrar una forma alternativa de regulación emancipatoria.

ARTICLE INFO ABSTRACT The presence and concentrations of the sixteen EPA priority polycyclic aromatic hydrocarbons (PAHs) in roasted pork commonly consumed by Ugandans who hang out in local pubs were determined. A total of 28 ready to eat roasted pork samples obtained from two local pork joints in Kampala, Uganda were analyzed. The PAHs were detected and quantified using Gas Chromatography – Mass Selective Detector. The limit of detection (LOD) for each PAH in the roasted pork samples ranged from 0.02 – 0.09 µg/kg. The total PAHs were found to be 79.7 and 154.5 with the Benzo[a]pyrene 3.11 and 3.32 and PAH4 17.16 and 19.49 µg kg –1 for Wandegeya and Nakulabye samples respectively. Overall, the results indicate an appreciable amount of PAHs in the roasted pork samples. However, it may take frequent consumption of this diet before significant contributions of PAH exposure.

This study presents an improved method for quantitative analysis of imidacloprid residues in wheat grain using high performance liquid chromatography. The study used chromatographic response (in terms of peak height) as a quantitative tool for determination instead of peak area. The peak height of imidacloprid showed a very good linear correlation (R 2 = 0.999) when compared with absolute values at six different concentrations. The limit of detection was found to be 0.01 lg/mL. The recovery of imidacloprid residues in spiked wheat grain at three levels (0.03, 0.05, and 0.1 lg/g) was in the range of 79%-88% with %RSD 5.72 at 0.05 lg/g (w/w) and between 87% and 93% with %RSD 3.55 at 0.1 lg/g (w/w). At 0.03 lg/g (w/w) level, recovery was not within the recommended range of 70%-110%. Therefore, the lowest limit of quantification for this method was found to be 0.05 lg/g.

Das Internationale Krebsforschungszentrum IARC („International Agency for Research on Cancer“) der WHO hat im Rahmen seines Monographs-Programms im Februar 2011
eine Bewertung von 18 weiteren Stoffen vorgenommen, von denen einige natürlich, als zugesetzter Aromastoff oder als Kontaminant in Lebensmitteln oder kosmetischen Mitteln vorkommen können.

A monitoring study was carried out with the aim to assess the level of toxic metals i.e., lead (Pb),
cadmium (Cd), arsenic (As) and mercury (Hg) in different vegetables grown in Sindh province of
Pakistan during 2007-2008. Two hundred ten samples of twenty one vegetables were collected
from farmers’ field of Sindh and exporters at Karachi. These samples were grouped into four
categories viz., leafy, root and tuberous, cucurbits and fruity. The samples in duplicate were
digested with nitric and perchloric acid mixture with 3:1 ratio. Cadmium and Pb were analyzed
with Graphite Furnace Atomic Absorption Spectrophotometer and As and Hg on Atomic
Absorption using Vapor and Hydride Generation Assembly. Average concentration of Cd, Pb, As
and Hg in leafy vegetables was found 0.083 μgg-1, 0.05 μgg-1, 0.042 μgg-1 and 0.008 μgg-1
respectively, in roots and tuberous vegetables was 0.057 μgg-1, 0.03 μgg-1, 0.045 μgg-1 & 0.004
μgg-1 respectively, in cucurbit vegetables was 0.021 μgg-1, 0.051 μgg-1, 0.056 μgg-1 and 0.0089
μgg-1 respectively and in fruity vegetables was 0.035 μgg-1, 0.067 μgg-1, 0.054 μgg-1 and 0.007
μgg-1 respectively. In leafy vegetables, the concentration of cadmium, lead and mercury were
found comparatively higher than other three groups of vegetables. However, concentration of
heavy metals found in the samples of all four categories of vegetables, was within the permissible
limits and safe to consume.

A monitoring study was carried out with the aim to assess the level of toxic metals i.e., lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in different vegetables grown in Sindh province of Pakistan during 2007-2008. Two hundred ten samples of twenty one vegetables were collected from farmers' field of Sindh and exporters at Karachi. These samples were grouped into four categories viz., leafy, root and tuberous, cucurbits and fruity. The samples in duplicate were digested with nitric and perchloric acid mixture with 3:1 ratio. Cadmium and Pb were analyzed with Graphite Furnace Atomic Absorption Spectrophotometer and As and Hg on Atomic Absorption using Vapor and Hydride Generation Assembly. Average concentration of Cd, Pb, As and Hg in leafy vegetables was found 0.083 μgg-1, 0.05 μgg-1, 0.042 μgg-1 and 0.008 μgg-1 respectively, in roots and tuberous vegetables was 0.057 μgg-1, 0.03 μgg-1, 0.045 μgg-1 & 0.004 μgg-1 respectively, in cucurbit vegetables was 0.021 μgg-1, 0.051...

El presente documento presenta los resultados de análisis de datos por encuesta a para una población de consumo alimentos procesados con aditivos alimentarios, presentando su efecto, uso y cantidades máximas permitidas por los diferentes organismos internacionales. Toda la información recabada fue usada para investigación y exposición científica, por tal motivo no se solicitaron datos que lo puedan comprometer al encuestado. Se busca ayudar a personas a reflexionar en el futuro a tomar mejores decisiones al comprar productos procesados con aditivos destacando principalmente que el uso de estos está controlado, normado y su uso es seguro para la alimentación humana.

This study presents an improved method for
quantitative analysis of imidacloprid residues in wheat
grain using high performance liquid chromatography. The
study used chromatographic response (in terms of peak
height) as a quantitative tool for determination instead of
peak area. The peak height of imidacloprid showed a very
good linear correlation (R2 = 0.999) when compared with
absolute values at six different concentrations. The limit of
detection was found to be 0.01 lg/mL. The recovery of
imidacloprid residues in spiked wheat grain at three levels
(0.03, 0.05, and 0.1 lg/g) was in the range of 79%–88%
with %RSD 5.72 at 0.05 lg/g (w/w) and between 87% and
93% with %RSD 3.55 at 0.1 lg/g (w/w). At 0.03 lg/g
(w/w) level, recovery was not within the recommended
range of 70%–110%. Therefore, the lowest limit of quantification
for this method was found to be 0.05 lg/g.

Nuclear magnetic resonance spectroscopy is introduced for the analysis of alcoholic beverages in the context of governmental health and safety control. For sample preparation of all types of alcoholic beverages, only addition of buffer is required as single step. To detect potentially unsafe samples especially in the context of unrecorded alcohol (i.e., illegally or informally produced alcohol), a nontargeted approach based on principal component analysis (PCA) was applied. The PCA scores plot of 304 samples clearly shows seven conspicuous samples with highly divergent scores from the rest of the samples. These samples contained hazardous substances such as diethyl phthalate or polyhexamethyleneguanidine, as well as extremely high concentrations of methanol or ethyl carbamate. In addition to the nontargeted approach, partial least squares regression allowed us to quantify several parameters such as methanol, higher alcohols, 2-phenyl alcohol and ethyl acetate with high correlation to gas chromatographic reference analysis (R 2 = 0.92-0.98).

The presence of endocrine disruptors bisphenol-A, bisphenol-A-dimethacrylate, bisphenol-A-diglycidyl-ether, phthalic-acid, dibutyl-phthalate, diethyl-phthalate and dioctyl-phthalate was determined in vegetable cans, baby bottles and microwaveable containers from the Mexican market. Gas-Chromatography-Mass-Spectrometry was used for the identification and High-Performance-Liquid-Chromatography with UV/Visible light and fluorescence detectors was used for the quantification. Endocrine disruptors were found in all samples. PA and DOP were the substances most commonly found, and maximum concentrations were 9.549 and 0.664 lg/kg, respectively from a jalapeno peppers can. Bisphenol A, phthalic-acid, bisphenol-A-dimethacry-late, bisphenol-A-diglycidyl-ether, dioctyl-phtalate and dibutyl-phthalate were found in baby bottles and micro-waveable containers.

Response Surface Methodology (RSM) was used to establish the optimum time and temperature for production of acid-hydrolysed winged bean protein (aHWBP) and acid-hydrolysed soybean protein (aHSBP). Seven hours of hydrolysis at 125 °C was the optimum condition for producing aHWBP, whereas it was 5 h of hydrolysis at 125 °C for production of aHSBP. Although aHWBP and aHSBP produced using these conditions had favourable sensory qualities, they were found to have up to 25 mg kg)1 of 3-monochlo-ropropane-1,2-diol (3-MCPD). This exceeds the maximum level permissible in Commission Regulation (EC) No 466/2001. However, additional alkaline thermal treatment at pH 8.5 for 2 h at 100 °C effectively reduced the 3-MCPD contents of aHWBP and aHSBP to undetectable levels. aHWBP has a distinctive flavour, which is different from that of aHSBP. The former has higher mean scores for meaty and vegetable attributes but lower mean scores for soy, umami and beany attributes than the latter.

A monitoring study was carried out with the aim to assess the level of toxic metals i.e., lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in different vegetables grown in Sindh province of Pakistan during 2007-2008. Two hundred ten samples of twenty one vegetables were collected from farmers' field of Sindh and exporters at Karachi. These samples were grouped into four categories viz., leafy, root and tuberous, cucurbits and fruity. The samples in duplicate were digested with nitric and perchloric acid mixture with 3:1 ratio. Cadmium and Pb were analyzed with Graphite Furnace Atomic Absorption Spectrophotometer and As and Hg on Atomic Absorption using Vapor and Hydride Generation Assembly. Average concentration of Cd, Pb, As and Hg in leafy vegetables was found 0.083 µgg -1 , 0.05 µgg -1 , 0.042 µgg -1 and 0.008 µgg -1 respectively, in roots and tuberous vegetables was 0.057 µgg -1 , 0.03 µgg -1 , 0.045 µgg -1 & 0.004 µgg -1 respectively, in cucurbit vegetables was 0.021 µgg -1 , 0.051 µgg -1 , 0.056 µgg -1 and 0.0089 µgg -1 respectively and in fruity vegetables was 0.035 µgg -1 , 0.067 µgg -1 , 0.054 µgg -1 and 0.007 µgg -1 respectively. In leafy vegetables, the concentration of cadmium, lead and mercury were found comparatively higher than other three groups of vegetables. However, concentration of heavy metals found in the samples of all four categories of vegetables, was within the permissible limits and safe to consume.

Due to its versatility and wide range of applications, activated carbon is widely used as contaminant removal media. Recent research have focused on enhancing the effectiveness of activated carbon by modifying their specific properties in order to enable the carbon to develop affinity for certain contaminants. In view of this, a comprehensive list of literatures on chemical, physical and biological modification techniques of activated carbon pertaining to enhancement of contaminant removal from aqueous solutions was compiled and reviewed. Acidic treatment to introduce acidic functional groups onto surface of activated carbon was by far, the most studied technique. It was apparent from the literature survey that the beneficial effects of specific modification techniques on activated carbon adsorption of targeted contaminant species from aqueous solutions were profound, with some studies reported increase of contaminant uptake factors of more than 2. Concurrently, considerable decreases associated with certain contaminant uptakes can also occur depending on the technique used. © 2006 Elsevier B.V. All rights reserved.

http://ac.els-cdn.com/S1383586606002024/1-s2.0-S1383586606002024-main.pdf?_tid=7b23a968-2364-11e4-9576-00000aacb35d&acdnat=1407987699_aba94f9d1a7a015e586e5e52cec152db 
http://www.sciencedirect.com/science/article/pii/S1383586606002024

Wheat varieties collected from three districts of Sindh Mirpurkhas, Nawabshah and Khairpur were analyzed to assess the
accumulation of toxic (Pb, Ni & Cr) and essential (Zn & Cu) metals. Mean zinc concentration (μg-g-1) in the varieties,
Sarsabz, Inqlab, Anmol, V- 7001, Rabel (in-line), Yakora, Mehran, Sindh- 83, V- 7005, Moomal, TD- 1, TJ- 83, Wattan and
V- 5000 was 18.72, 21.29, 21.75, 30.28, 37.53, 21.17, 18.81, 20.89, 24.44, 27.70, 21.93, 24.98, 22.11 and 17.25 (μg-g-1),
respectively. Mean copper concentration (μg-g-1) in these varieties was 1.64, 2.29, 2.85, 2.06, 3.87, 3.38, 3.80, 4.32, 2.86, 2.57,
1.74, 2.67, 2.17 and 2.0 (μg-g-1), respectively. Where as Pb, Ni and Cr were not detected in these samples. In all the varieties
of Mirpurkhas, Nawabshah and Khairpur mean Zn and Cu content found were 20.95 and 2.19, 24.98 and 3.38, 21.64 and 2.20
(μg-g-1), respectively. It was concluded from results that wheat varieties grown in three district of Sindh were free from toxic
metals contamination and safe for human consumption.

SO 14000 has opened the field for enhancing the awareness towards healthy environment and gives the
ideology of regular assessment of threshold values not only of nutrients but contaminants as well. Under this statement
microbiological studies in terms of mycoflora followed by physical characteristics and level of some essential elements Mg, Fe,
Cu and Zn, and deleterious metal Cd were analyzed in fresh milk samples (FMS) and tetra pack milk or UHT processed milk
samples (PMS) available in Gulshan-e-Iqbal Town, Karachi for the residents. Samples were collected in the morning time during
winter season. Physical parameters like pH, conductivity, density, viscosity, surface tension and refractive index were observed
very soon after sample collection. Percentage of ash and total dissolved solids (TDS) were also measured. For fungal flora
studies PDA (Potato Dextrose Agar) and Sabourouds Agar were used for the fungal growth. The concentrations of metals
considered were estimated after wet digestion of samples using atomic absorption spectroscopy. The ranges of average
concentration of Mg, Fe, Cu and Zn were found to be 77.120 – 141.915mg/l, 0.580 – 7.320mg/l, 0.004 – 0.070mg/l and 2.574 –
4.872mg/l. The level of Cd was estimated in the samples between 0.0050 – 0.053mg/l, but was not observed in most of the
samples. Among the fungi, the highest diversity was that of Aspergillus spp. that produces aflatoxins.