VOLUME 33, NO6, DEC 2011

Effect of UHT Processing and Storage Conditions on Physico-chemical Characteristics of Buffalo Skim Milk

The obtained results indicated that physico-chemical and nutritional changes in UHT processed buffalo skimmed milk were more pronounced at 45°C than 25°C and 10°C. Duration of storage adversely affected the chemical and nutritional quality of processed milk. A slight decrease in pH, total ash and lactose contents, was observed, whereas acidity was increased on the mentioned storage conditions. Total nitrogen and casein nitrogen contents gradually decreased during storage, whereas non-casein nitrogen (NCN) and non-protein nitrogen (NPN) increased to a great extent in samples stored at higher temperatures. A significant increase in hydroxyl methyl furfural (HMF) values occurred in UHT processed buffalo skim milk at 25°C and 45°C after of 90 days storage. Storage at high temperature (45°C) caused undesirable effects on sensory properties, general quality characteristics and acceptability of UHT buffalo skimmed milk.read more

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IMTIAZ HUSSAIN ,

Gasification Characteristics of Auto Shredder Residue

Given the large volume of used tyre waste generated each year it is imperative that suitable re-use and disposal techniques are developed for dealing with this problem; presently these include rethreading, reprocessing for use as safe playground and sports surfaces, use as noise reduction barriers and utilisation as a fuel source. This paper reports on pilot scale studies designed to investigate the suitability of automotive waste for energy recovery via gasification. The study was carried out into auto shredder residue, which is a mixture of three distinct waste streams: tyres, rubber/plastic and general automotive waste.  The tests included proximate, ultimate and elemental analysis, TGA, as well as calorific value determinations. In addition, the waste was tested in a desktop gasifier, and analysis was carried out to determine the presence and type of combustible gases.  It was concluded that tyre waste and rubber/plastic waste are quite suitable fuels for gasification.read more

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ABDULLAH MALIK ,MUHAMMAD AKRAM ,SHAHID NAVEED ,ROSKILLY AP ,NAVEED RAMZAN ,

Historical Development of Magnetite Nanoparticles Synthesis

Top down and bottom up are two fundamental routes for the formation of magnetite nanoparticles (MNPs). These routes are generally utilized for producing technologically and economically significant MNPs. This review discusses the synthesis of MNPs and outlines methods of preparation that allow control over the size, morphology, surface treatment and magnetic properties of the nanoparticles. In the past, long grinding of bulk magnetite in the presence of stabilizing surfactants produced the first accepted ferrofluid containing MNPs. Such mechanogrinding methods were inherently time consuming and costly. Currently, perhaps the most commonly accepted approaches for creating MNPs concentrate around different forms of coprecipitation, microemulsion, biological nanoreactors, sol-gel and polyol methods. Various additional methods also exist for the controlled synthesis of MNPs including ultrasound irradiation (sonochemical synthesis), spray and laser pyrolysis.read more

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FARIDULLAH KHAN ,NAZIR SHAH KHATTAK ,UMAR SAEED KHAN ,AMINUR RAHMAN ,

Concentration of Residual Copper in the Bitter Gourd Samples Available in Punjab-Pakistan

Copper is very common substance that occurs naturally in the environment and spread through natural phenomena. Human widely use copper. In agriculture copper sulfate is used as a pesticide and fertilizer. The trade includes many different chemical compounds that are used for vide variety of pest problems. The use of pesticide has improved the efficiency of growing crops & the quality as well as quantity of food produced. An atomic Absorption spectroscopic method was developed for determination of residual copper. Copper content was determined in duplicate. The copper concentration varied from 0.578-3.70 mg kg-1. Residual copper contents determined in this study exhibited that fruits and vegetables from this part of the Asia could serve as good dietary source for essential trace metals and the residual copper levels are almost within safety limits for human consumption.read more

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MUHAMMAD USMAN SABRI ,ABDUL QAYYUM ATHER ,PHOOL SHAHZADI ,

Localization of Streptolysin S (SLS) by Blood Agar Overlay Technique (Zymogram)

Streptolysin S (SLS) is the non-antigenic, oxygen-insensitive cytolysin which is produced by Group A streptococci. It is largely responsible for a zone of beta-haemolysis surrounding colonies on blood agar media.   In this paper it is described, for the first time, reliable detection, visualization and quantification of SLS using blood agar overlay (zymogram) method. This technique is sensitive and protocol describes a method with broad potential to elucidate previously undetectable biological activity of streptomycin S (SLS) on gel electrophoresis.read more

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BADARUDDIN A. MEMON ,

Assessment of Pesticide Residues on Selected Vegetables of Pakistan

The present study was conducted to determine the pesticide residues on selected summer vegetables.  Five vegetables were grown with three replicates in a split plot randomized complete block design.  Pesticides were sprayed on vegetables thrice at regular intervals each after 15 days.  At maturity the pesticides residues were extracted from edible and leaf portions using anhydrous sodium sulfate and ethyl acetate while adsorption chromatography technique was used for cleanup. The extracts were subjected to high performance liquid chromatography (HPLC) for separation and analysis of the compounds. Significant differences (p<0.05) were found in the pesticides residues on edible portions whereas highly significant differences (p<0.001) were observed for the leafy portions.  The residual level of cypermethrin was highest (16.2 mgkg-1) in edible portion of bitter gourd, while Lambdacyhalothrin and Mancozeb residues were detected high (4.50 mgkg-1, 6.26 mgkg-1) in edible portion of bitter gourd and Cucumber respectively. Cypermethrin residues were high (1.86 mgkg-1) in Okra leaves. Mancozeb and Lambdacyhalothrin residual level was high (1.23mgkg-1, and 0.0002 mgkg-1) in chili and tomato leaves.  Cypermethrin residues were readily detected in edible and leaf portion of the selected vegetables.read more

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MOHAMMAD MAROOF SHAH ,AMJAD HASSAN ,QAISAR MAHMOOD ,KEHKASHAN AKBAR ,MUHAMMAD SAQIB KHAN ,

Ultrasound-Assisted Emulsification–Microextraction Combined with Flame Atomic Absorption Spectrometry for Determination of Trace lead in Water Samples

The process of ultrasound-assisted emulsification–microextraction (USAEME) was successfully applied for the extraction and preconcentration of trace lead from water samples, prior to flame atomic absorption spectrometry (FAAS). In the proposed approach, dithizone was used as a chelating agent; carbon tetrachloride was selected as extraction solvent. Some effective parameters on the microextraction and the complex formation were selected and optimized. These parameters included extraction solvent type as well as extraction volume, time, temperature, and pH, the amount of the chelating agent, and salt effects. Under optimum conditions, an enrichment factor of 91 was obtained from only 7.0 mL of water sample. The calibration graph was linear in the range of 3.76-600 μg/L with a detection limit of 1.14 μg/L. The relative standard deviation (R.S.D) for ten replicate measurements of 20 and 600 μg/L of lead were 3.23 and 2.56%. This proposed method was successfully applied to tap water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments. Operation simplicity, low cost, high enrichment factor, and low consumption of the extraction solvent are the main advantages of the proposed method.read more

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YU KUN WANG ,JING WEN ZHANG ,XIN DU ,JING JUN MA ,JING CI LI ,HE QING GAO ,

Effect of Solid Waste on Heavy Metal Composition of Soil and Water at Nathiagali-Abbottabad

This experiment concluded that the waste material produced tangible impacts on soil and water system of Nathiagali. The dumping of waste resulted in a marked increase in the concentration of metals in soils and the measured metals varied in the order of Mn > Fe > Zn > Cu > Pb > Ni > Cu. The metal species were found higher on the site of waste accumulation and decreased with the increasing distance from the dumping site. The dumping place had the highest soil EC as compared to the nearby soils. The pH trend was found apparently inconsistent. Water samples exhibited higher content of heavy metals. This could be attributed to the leachates percolated from the solid and liquid wastes. Metal concentrations were found in excess to the WHO water quality standards. Therefore, an effective awareness, recycling and land filling techniques for the solid waste management in the study area is urgently needed.read more

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TARIQ KHAN ,FARID- ULLAH ,MUHAMMAD IRSHAD ,NOREEN MALIK ,

Minerals and Nutritional Composition of Camel (Camelus dromedarius) Meat in Pakistan

The quality of camel meat has received little attention so far in Pakistan. It is nutritionally as good as that of the major sources of red or white meat. Camel is a desert animal but is not less than other red meat animals (beef, lamb and goat) in its composition. The proximate composition, fatty acid profile and mineral contents of the local camel (Camelus dromedarius) meat have been investigated. It contained 72.03 ± 0.014% water, 4.45 ± 0.011% ash, 5.79 ± 0.012% fat and 66.42 ± 0.534% protein. It has been found that camel meat has relatively more moisture, less fat, less ash and similar protein content than that of beef, lamb and goat [1]. It has similar mineral composition (Na, K, Ca, Fe, Zn, P, Mg, Cd, Cr, Co, Mo, Ni, and Pb) to beef except for sodium. Fatty acid profile for camel meat oil showed high content of palmitic acid and oleic acid. These two fatty acids are essential in human nutrition. In view of the above, it is possible that camel meat could make a greater contribution to the growing need for meat in developing countries like Pakistan.read more

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SAKHWAT ALI ,RABIA REHMAN ,AADIL ABBAS ,TARIQ MAHMUD ,JAMIL ANWAR ,MUHAMMAD SALMAN ,

Intercomparison Exercises; A Requirement for Accurate and Precise Analytical Data

External evaluation of laboratory results and procedures can be carried out by participation in intercomparison exercises. The results of the International Atomic Energy Agency - Marine Environmental Laboratory (IAEA-MEL), Monaco intercomparsion exercise IAEA-158, marine sediment are presented and discussed in this paper. Using four different irradiation protocols instrumental neutron activation analysis (INAA) was used to quantify Al, As, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, V, Yb and Zn in this reference material (RM). IAEA-405 (Estuarine Sediment) and IAEA-SL1 (Lake Sediment) were used as compatible matrix RMs for quality assurance (QA) purposes. The Z-scores showed our results to be in very good agreement with the IAEA certified values. Furthermore the IAEA placed our laboratory in Group 1 for having ≥ 90% of the data with acceptable Z-scores.read more

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NAILA SIDDIQUE ,S. WAHEED ,