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Article
Publication date: 4 March 2014

Aneela Qadeer, Humera Anwer, Talat Mahmood and Muhammad Abbas Bhutto

Nutritional and medicinal properties of black sesame seeds (Sesamum indicum) make it very valuable in traditional system of food. Minerals in Sesamum indicum play an…

Abstract

Purpose

Nutritional and medicinal properties of black sesame seeds (Sesamum indicum) make it very valuable in traditional system of food. Minerals in Sesamum indicum play an important role to enhance its nutritional value. The present research comprises on proximate and chemical analysis of Sesamum indicum. This study is also based on the development of ashing methods for extraction of metals in black sesame seeds. The paper aims to discuss these issues.

Design/methodology/approach

Black sesame seeds were taken from local market at Karachi-Pakistan. Proximate analysis of seeds comprises of moisture content, ash content and total metal content by EDTA titration. Digestion of this herb was done in different medium, i.e. HNO3, HCl, H2SO4 and simple ash (ash was prepared without using any acid). Atomic absorption spectroscopy was used for the analysis of metals, i.e. Fe, Zn, Cu and Mg in all these ashes.

Findings

From the results it is concluded that best medium for ashing is H2SO4, by which maximum ash (5.39±0.0021 per cent) produced. Qualitative analysis (based on Ksp values) also confirmed the presence of maximum number of metals in H2SO4 medium. Complexometric titration also revealed that maximum metal content was found to be in HCl and H2SO4 ash. Results from atomic absorption spectroscopy revealed that H2SO4 is the best method for copper (0.399±0.0001 mg/g) and iron (0.3993±0.0015 mg/g), while simple ash can extract zinc and magnesium at their maximum level.

Originality/value

This research demonstrates the best ashing method for the extraction of micronutrients, present in Sesamum indicum. These micronutrients are very beneficial for human health.

Details

Nutrition & Food Science, vol. 44 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 11 March 2019

Rita Mansour

The purpose of this paper was to determine and compare nutritional composition of different parts of citrus fruits, namely, Citrus aurantium (peel: albedo, flavedo and

Abstract

Purpose

The purpose of this paper was to determine and compare nutritional composition of different parts of citrus fruits, namely, Citrus aurantium (peel: albedo, flavedo and pulp: juice, pomace) . This study was conducted through three stages of fruit maturity (green, yellow and orange). Total polyphenols, flavonoids, β-carotene, total chlorophyll, ascorbic acid, acidity, total soluble solid and the minerals (Ca, Mg, Zn, Na, K, Fe, Mn Cu) were evaluated. Moreover, the relationship between the total polyphenol, flavonoids and the antioxidant activity was determined.

Design/methodology/approach

Total polyphenols were determined by the Folin-Ciocalteu method. Flavonoids were assessed by the aluminum chloride colorimetric method. Ca, Mg, Zn, Fe, Mn and Cu were measured using an atomic absorption spectrophotometer. K and Na contents were determined by using a flame photometer. Other nutritional composition was determined by volumetric method.

Findings

The result showed that the concentrations of antioxidants, total polyphenols, flavonoids, vitamin C, total chlorophyll, total acidity and antioxidant activity (DPPH%) decreased during the maturity of fruit while the value of pH and β-carotene increases. In addition, the concentrations of the most minerals decreased through the maturation of fruit except Na. Anova statistical analysis of all the studied chemical variables was shown significant differences between all the samples. The pH, total soluble solids, β-caroteniod: orange juice had the highest average while green juice had the lowest. Ascorbic acid, total acidity, total chlorophyll: green juice had the highest average while orange juice has the lowest. Total phenol, K, Mg, Fe, Cu, Mn: green flavedo had the highest average while orange juice had the lowest. Flavonoid, antioxidant activity (DPPH%), Ca, Zn: green albedo had the highest average while orange juice had the lowest. Na: orange flavedo had the highest average while green juice had the lowest. The correlations between total polyphenol, flavonoid and antioxidant capacity were significantly higher (R = 0.935 and 0.960, respectively).

Originality/value

The stage of maturity affects nutritional composition in Citrus aurantium fruits (C. aurantium) peel and pulp, where some minerals of composition increased and others decreased, according to the results. This is the first study on comparing the nutritional composition of pulp: juice, pomace and peel: albedo, flavedo of Citrus aurantium L. during maturity in Syria, and it was also not found in previous works.

Details

Nutrition & Food Science, vol. 49 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 27 March 2009

Fiaz Ahmad, Arshad Munir, Zafar‐uz‐Zaman and Naveed Zafar Ali

The purpose of this paper is to establish some acceptable trends in the contamination of roadside vegetation and to define a safety limit regarding the effects of metal

Abstract

Purpose

The purpose of this paper is to establish some acceptable trends in the contamination of roadside vegetation and to define a safety limit regarding the effects of metal contamination arising from various toxic metals deposited on leaves of the plants and in the bulk of the fruits.

Design/methodology/approach

Distribution of essential and non‐essential elements on the surface of leaves and in bulk of fruits of specific areas of Multan (Pakistan) was estimated and correlated with World Health Organization (WHO) standards. The metal concentrations are expressed as X ± SD for triplicate sub samples with the SD of ± 1.0‐1.5 per cent. The maximum metal levels in bulk of various fruits were calculated for FE, followed by Cu, Zn and Co.

Findings

In samples from roadside leaves Fe (823 mg/kg) was found to be the dominant metal, whereas the observed threshold level was found for Co (17.25 mg/kg). The non‐essential elements in various fruits, the Cr was found to be the dominate (16 mg/kg) on mean basis as compared with other metals in fruits. The increasing order of non‐essential metals on the surface of roadside leaves was Li < Ni < Sr < Pb < Cr. The results revealed that metal concentration decreases with increase in distance from roadside (10, 30 and 50 m) with negative correlation coefficient.

Originality/value

This paper shows that the metals concentration in case of all fruit samples fall within the permissible safe limit, whereas the metal concentrations on the surface of roadside leaves were found to surpass the safe limits laid down by the WHO. It is consequently suggested that edible portions of vegetation and fruits near highways should be consumed cautiously.

Details

Nutrition & Food Science, vol. 39 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 January 1973

Alan Tolan

There appears to be no clear chemical definition of the term, heavy metal, but in the broadest sense the term seems to be restricted to metals of greater atomic number…

Abstract

There appears to be no clear chemical definition of the term, heavy metal, but in the broadest sense the term seems to be restricted to metals of greater atomic number than calcium. Thus, nutritionally essential trace elements such as copper, zinc and manganese are heavy metals along with others which are not regarded as serving any useful function in the body such as lead and mercury. It is not certain how many metals are naturally present in food and clearly this will depend on factors such as the source and type of food but it is probable that many metals which occur in nature will also occur in minute traces in food. In practice most of these present no problem and from the point of view of food contamination only a few of the heavy metals, in particular lead, mercury and cadmium, at the present time are of real interest. It is worth noting that some of the essential trace metals may act as contaminants if certain levels are exceeded.

Details

Nutrition & Food Science, vol. 73 no. 1
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 February 2003

M. Jaffar and Khalid Masud

Levels of selected essential and non‐essential metals (Cd, Cr, Pb, Cu, Fe and Zn) and those of macro‐nutrients (Ca, K, Mg and Na) are estimated in 15 different seasonal…

Abstract

Levels of selected essential and non‐essential metals (Cd, Cr, Pb, Cu, Fe and Zn) and those of macro‐nutrients (Ca, K, Mg and Na) are estimated in 15 different seasonal fruits available in local Pakistan markets. The wet digestion oxidation method was used for the analysis of samples by the flame atomic absorption technique. The results indicated almost 100 percent incidence of occurrence of trace metals and macro‐nutrients in all fruits. The highest concentration was observed for zinc, ranging between 0.13 and 79.9mg/kg, wet weight, respectively for banana and mango. The iron levels ranged from 0.55 to 44.8mg/kg, wet weight, for pomegranate and mango. The concentrations of Cd, Cr, Pb and Cu remained at marginal levels, except for certain fruits where the concentrations were very high. The data are compared with allowed safe limits laid down by WHO.

Details

Nutrition & Food Science, vol. 33 no. 1
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 December 2003

Abdul Waheed, M. Jaffar and Khalid Masud

Levels of selected essential metals (Cu, Fe and Zn) and non‐essential metals (Cd and Pb) were determined by the wet digestion based atomic absorption flame…

Abstract

Levels of selected essential metals (Cu, Fe and Zn) and non‐essential metals (Cd and Pb) were determined by the wet digestion based atomic absorption flame spectrophotometric method in twenty canned foodstuffs of local and foreign origin. The study revealed that on average, the concentrations of Fe, Cd and Pb in local foodstuff were more than those found in imported canned products. The contents of Fe and Pb in local canned food were almost double that of the counterpart imported versions. Analysis of the construction materials of the tins indicated that some metals, such as Pb, had levels twice as high as those found in the foreign tin containers. The results showed that the Cu concentration in various foodstuffs ranged between 0.04 and 8.88mg/kg, Fe between 3.07 and 126mg/kg, Zn between 0.19 and 22.8mg/kg, Cd between 0.15 and 1.16mg/kg and Pb between 0.11 and 2.04mg/kg. The results are compared with the levels of metals in corresponding data from the literature.

Details

Nutrition & Food Science, vol. 33 no. 6
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 April 2004

M. Jaffar, Munir H. Shah, N. Shaheen, A. Khaliq, Saadia R. Tariq, S. Manzoor and M. Saqib

Levels of 12 metals (Ca, K, Na, Mg, Cu, Fe, Mn, Zn, Cd, Cr, Pb and Ni) were estimated in 19 different imported brands of unexpired and expired canned dry milk available…

Abstract

Levels of 12 metals (Ca, K, Na, Mg, Cu, Fe, Mn, Zn, Cd, Cr, Pb and Ni) were estimated in 19 different imported brands of unexpired and expired canned dry milk available from local markets. The HNO3/HClO4‐based wet digestion method was used for the analysis of the samples by the FAAS technique under optimum analytical conditions. Of the macronutrients, Ca showed highest at 1,144 μg/g in the dry milk from Holland. In the case of micronutrients, Fe showed the maximum level at 119.15 μg/kg in the milk from UK. Cr dominated at 23.19 μg/kg compared with other heavy toxic trace elements. The following order of decreasing concentration was observed for both unexpired and expired milk: Ca > Na > K > Mg > Fe > Zn > Cr > Pb > Cu > Ni > Cd. All the trace elements were found to have 100 per cent incidence of occurrence. The expired milk samples showed enhanced levels of Fe, Zn, Cr and Pb by a factor of 1.2‐1.6 on average. The results of the metal contents were compared with those for fresh cow milk. The data were statistically evaluated to find bivariate correlation between the metals in pre‐ and post‐expiry milks.

Details

Nutrition & Food Science, vol. 34 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 February 1956

N.L. Evans

The rapidly expanding use of highly alloyed metals, such as stainless steels and special heat‐resisting alloys, and their fabrication by deep stamping, spinning and

Abstract

The rapidly expanding use of highly alloyed metals, such as stainless steels and special heat‐resisting alloys, and their fabrication by deep stamping, spinning and welding, with the annealing and stress‐relieving treatments essential to these processes, have called for an entirely new outlook on methods of scale removal. From both the economic and the dimensional points of view, it is essential to minimise metal losses in all stages of manufacture, and this is achieved with the non‐electrolytic sodium hydride process, here described.

Details

Anti-Corrosion Methods and Materials, vol. 3 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 May 2010

Pravin Singare, Ram Lokhande, Mahadeo Andhale and Raghunath Acharya

Elemental analysis of these medicinal plants was performed by employing Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS…

Abstract

Elemental analysis of these medicinal plants was performed by employing Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS) techniques. The samples were irradiated with thermal neutrons in a nuclear reactor and the induced radio activity was counted by gamma ray spectrometry using an efficiency calibrated high resolution High Purity Germanium (HPGe) detector. Most of the medicinal plants were found to be rich in one or more of the elements under study. The variation in elemental concentration in same medicinal plant samples collected from different regions was studied and the biological effects of these elements on human beings are discussed. The study was also extended further to estimate the level of toxic elements like Cr, Cd, Ni, Pb and Hg in medicinal plants which arises due to environmental pollution. The results were discussed with careful reference to established role of essential and rare elements to the physiology and pathology of plant and human life.

Details

World Journal of Science, Technology and Sustainable Development, vol. 7 no. 2
Type: Research Article
ISSN: 2042-5945

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Article
Publication date: 9 March 2010

Steven B. Young, Alberto Fonseca and Goretty Dias

This paper seeks to critically analyse the list of principles on the extractive phase of the electronics supply chains, proposed for consumer electronic companies, by the…

Abstract

Purpose

This paper seeks to critically analyse the list of principles on the extractive phase of the electronics supply chains, proposed for consumer electronic companies, by the non‐governmental campaign MakeITfair. The purpose is to understand whether conformance with these principles could positively influence the socio‐environmental conditions at the mining level.

Design/methodology/approach

The paper reviews the literature on incorporation of corporate social responsibility in supply chain management. It then examines how metals are mined, traded and used in electronics, as well as how the mining industry has been managing its own socio‐environmental problems. This information underpins the qualitative discussion of the principles.

Findings

MakeITfair's principles were found to be constructive insofar as they draw the attention of electronic companies to their shared responsibility for the problems of distant‐tier suppliers. Nevertheless, some principles may lead to potentially undesired outcomes such as biased prioritization of mining companies or regions, adoption of contentious “standards”, and conflicts concerning the sovereign rights of nations over their natural resources. Overall, the principles stress traceability mechanisms as means of influencing the mining phase of supply chains without considering the costs and benefits of overcoming the complexities involved in the metal trade and other barriers. The paper concludes by highlighting the need to consider additional ways of positively influencing metals supply.

Research limitations/implications

The paper points out specific research priorities in the value chains of metals.

Originality/value

The paper provides a critical analysis of intricate responsibility issues in the supply chain of the world's top electronic companies.

Details

Social Responsibility Journal, vol. 6 no. 1
Type: Research Article
ISSN: 1747-1117

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