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AAnnaallyyttiiccaaISllS N : 0974-7419 Volume 13 Issue 3 CCHHEEAnMM IndIIiSaSnT TJoRuRrnYaYl

Full Paper ACAIJ, 13(3) 2013 [118-125] Evaluation of essential and toxic metals in bakery foods consumed in Chittagong (Bangladesh)

Jewel Das1*, Suman Das1, Md.Abu Bakar1, Apollo Biswas2, Monir Uddin2 1BCSIR Laboratories, Chittagong, (BANGLADESH) 2Department of Chemistry, University of Chittagong, Chittagong, (BANGLADESH) E-mail : [email protected] ABSTRACT KEYWORDS

The concentration of essential metals such as potassium (K), Iron (Fe), Bakery foods; Calcium (Ca), Copper (Cu), Magnesium (Mg), Cobalt (Co), Zinc (Zn) & Essential metals; Manganese (Mn) and toxic metals such as Lead (Pb), Cadmium (Cd), Chro- Toxic metals; mium (Cr) & Nickel (Ni) were evaluated in Bakery Foods consumed in AAS; Chittagong, Bangladesh. In the sampling step fourty samples of eleven Chittagong. types of Bakery food item were collected and analyzed after dry ashing by using Atomic Absorption Spectrometer (AAS). The essential metal evalu- ation in the investigated samples indicated the following range of con- centration: K: 2.18 -162.62 mg kg-1, Fe: 1.01-33.47 mg kg-1, Ca: 4.86-138.06 mg kg-1, Cu: 0.05-5.14 mg kg-1, Mg: 35.55-593.26 mg kg-1, Co: BDL, Zn: 1.02- 14.80 mg kg-1, Mn: 1.34-9.62 mg kg-1. The essential metals concentration is in the range of human necessities. Pb, Cd, Cr and Ni were not detected at the ppm level in 67.5%, 87.5%, 100% and 72.5 % of analyzed bakery food sample respectively while in few food samples the concentrations of toxic metals were found: Pb: 0.06-1.21 mg kg-1, Cd: 0.08-0.47 mg kg-1, Ni: 0.49- 2.94 mg kg-1. All analyzed bakery products are safe to human health con- sidering the recommended daily allowance (RDA) and maximum permis- sible limits (MPL) value of Pb, Cd, Cr and Ni. The information obtained from the present investigation is expected to be useful to the general people of this region in selecting bakery foods as their diets.  2013 Trade Science Inc. - INDIA

INTRODUCTION than 90% for sodium and potassium[1]. The study of metal composition of foods is of great significance be- An element is essential for life if its removal from cause some of these metals are essential or toxic. Met- “re- the diet or other route of exposure to an organism als such as Fe, Cu, Mg, Mn, Co, Zn are essential for sults in a consistent and reproducible impairment of a human body but chronic metabolic disturbances may ” Human requirement for essen- physiological function. occur due to the deficiency or excess of these metals[2]. tial minerals vary from a few micrograms per day up to Human dietary deficiencies had been reported for Ca, [3] about 1g/day. Bioavailabilities of mineral nutrients vary Co (as vitamin B12), Cr, I2, Fe, Se and Zn . Deficien- from less than 1% for some forms of iron to greater cies of these minerals result from a combination of poor ACAIJ, 13(3) 2013 Jewel Das et al. 119 Full Paper bioavailability and low intakes. According to the U.S. toxic elements within consumable limits but some of the Agency for Toxic Substances and Disease Registry, food items bear noticeable amount of toxic metals[4]. there are more than 20 heavy metals, they tend to ac- Another analysis of heavy metal concentrations in veg- cumulate in the food chain and in the body and can be etables in Jessore shows that all of the vegetables com- stored in soft (e.g., kidney) and hard tissues (e.g., bone). monly consumed in diets contain dangerously high con- Being metals, they often exist in a positively-charged centrations of heavy metals[9]. The need to take action form and can bind on to negatively-charged organic to prevent and control contamination of the food chain molecules to form complexes. Non essential elements by heavy metals and trace elements in Bangladesh is such as Pb, Cd, Cr, Ni are considered to be toxic and therefore becoming increasingly obvious. their presence in the body can cause profound biochemi- It is also noticeable that cal and neurological changes in the body[4]. Modern People of all ages are affectionate of different bak- analytical techniques and ultra sensitive instruments ana- ery products, because of their taste, color and easy to lyzing metal contents even at ppb levels have recently digest nature. Bakery products are becoming promi- resolved several health disorders associated with in- nent day by day. Nowadays individuals have virtually take of toxic metals. Recent developments in toxicities no time to invest much on making breakfast it is the and other disorders resulting from ingestion of toxic bread and bun or biscuits which had occurred instead metals have compelled food regulators around the world of other sorts of stuff. There are numerous varieties of to revise the safe limits of these toxicants to ensure con- bakery products like bread, cakes, biscuits, pastries, sumer health. pizzas and they all are popular worldwide. The major Heavy-metal food intoxications are generally asso- route of entry of most metals into the body is through ciated with one of three patterns of occurrence, envi- the diet. Bakery products are consumed largely at ronmental pollution, accidental inclusion during process- Breakfast and/or Tiffin by the general people of ing and contamination during processing or storage of Bangladesh since it supplies carbohydrates, proteins and food. In Iranian flat bread analysis, the highest concen- certain inorganic micro nutrients that are vital for nor- tration of Pb, Cd and Ni were found 0.52 mg kg-1, mal growth of human. Bakery foods contain several 0.65 mg kg-1 and 2.67 mg kg-1 respectively[5]. In Paki- essential and trace elements even some toxic metals stan the concentration of Cd, Ni and Pb were observed also. However, their relative composition is not clearly in chocolates and candy samples was ranged as of ìg/g re- known as it should be and we have not enough infor- 0.099 - 0.353, 1.45 - 4.33 and 1.11 - 2.48 mation about the toxic metal contents in bakery foods spectively which indicated that cocoa-based chocolates which we are consuming everyday. The objective of have higher contents of toxic metals than milk- based this work is to estimate the levels of toxic metals such [6] chocolates and candies . In Southern Nigeria the mean as Pb, Cd, Cr and Ni as well as essential metals such concentrations of Zn, Fe, Cr, Mn, Ca, Mg, Ni, Pb, Cu. as K, Fe, Ca, Cu, Mg, Co, Zn and Mn in these foods Co and Cd in various biscuit classes were determined consumed in Chittagong & to provide suggestions for and it was found that the metal content was below per- actions to reduce contamination. missible limits except for nickel and lead in some types[7]. The level of heavy metals in foodstuffs has been re- MATERIALS AND METHODS ported around the world; from Sweden, USA, Egypt, [8] China, Nigeria, Italy, and Turkey . Preliminary studies Sample preparation in different parts of Bangladesh indicate that the food chain is exposed to contamination by heavy metals and In this study Forty samples of Eleven types of Bak- trace elements. A number of animal meats, organ meats, ery food products namely 1) Bread 2) Bakar Khani meat products and egg were analyzed which were col- [Dry flat bread] 3) Chocolate Cake, 4) Round Cake, lected randomly from six different market of Chittagong 5) Custard Cake, 6) Horlicks Biscuit 7) Bela Biscuit 8) city area, are the good sources of macro and micro Milk Marie Biscuit 9) Chanachur [Bombay mix/Hot mix/ nutrients and most of the studied foodstuffs contain the Chivdo] 10) Toast Biscuit 11) Butter Toast Biscuit of Anallyttiicall CHEAMn InIdSianT JoRurnYal 120 Evaluation of essential and toxic metals .in bakery foods consumed in Chittagong ACAIJ, 13(3) 2013 Full Paper available different brands were collected randomly from dissolved in 5 mL of HNO3 (25%, v/v) and, when nec- different fast food shops of Chittagong city area. A total essary, the mixture was heated slowly to dissolved the of 2-7 different brands were collected within each ma- residue. The dissolved portion was filtered through a jor group or type. The choice of the samples was care- Whatman No. 40 filter paper and the solution was trans- fully made to reflect the various brands consumed by ferred to 50 mL volumetric flask and made upto vol- different income classes and influenced availability as ume. A blank control was carried out in the same way of the time of the study. using the solvent alone. Sampling Analytical techniques ºc for three (3) hours. The sample was dried at 105 The samples were analyzed by an atomic absorp- Dried samples were powdered as well as homogenized tion spectrophotometer (Type: iCE 3300 AA system, using a porcelain crucible and stored in pre-cleaned Thermo Scientific, designed in UK) using an air acety- polyethylene bottles until analysis. lene flame. The analysis was carried out using respec- tive hollow cathode lamps under standard instrumen- Digestion procedure tal conditions (TABLE 1). All the spectroscopic mea- Dry ashing: 5 g of dried, homogenized sample were surements of the standard metal solutions as well as placed into a high form porcelain crucible and few drops the sample solutions were done at their respective ë of con. HNO3 were added to the solid as an ashing aid. wavelength of maximum absorptions max. The detec- Dry ashing process was carried out in a muffle furnace tion limit of the element for the instrument and the ºc by stepwise increase of the temperature up to 550 spike recovery rates of the elements analyzed under and then left to ash for about eight hours until a white or the experimental conditions were also determined gray ash residue was obtained[8,10]. The residue was (TABLE 1). TABLE 1 : Standard conditions used in determination of different elements, their detection limits, and spike recovery using atomic absorption spectrometer Wave Lamp Slid Fuel Burner Number Detection Spike Elements Length Current width Flow Height of Limits Recovery (nm) (mA) (nm) (L min-1) (mm) resamples (ppm) (%) K 766.5 8 0.5 1.2 7 3 0.0009 90-97 Ca 422.7 6 0.5 1.4 11 3 0.0037 92-98 Mg 285.2 12 0.5 1.1 7 3 0.0022 92-101 Fe 248.3 15 0.2 1.0 7 3 0.0043 92-97 Cu 324.8 5 0.5 1.1 7 3 0.0045 91-98 Mn 279.5 12 0.2 1.0 7 3 0.0016 92-99 1.2 Zn 213.9 10 0.2 7 3 0.0033 94-98 1.1 Pb 217.0 10 0.5 7 3 0.013 93-100 0.9 Ni 232.0 15 0.2 7 3 0.008 95-103 1.2 Cd 228.8 8 0.5 7 3 0.0028 95-102 1.0 Cr 357.9 12 0.5 8 3 0.0054 92-97 1.7 Co 240.7 15 0.2 7 3 0.01 93-102 Detection limit- the analyte concentration (or mass) that is equivalent to three times the standard deviation of twenty replicates of a blank sample. solutions of K, Ca, Fe, Cu, Mg, Mn, Co, Zn, Pb, Cd, Reagents and solutions Cr and Ni for AAS were obtained from BDH, England, The chemicals used for the analysis were of the A R for calibration purpose. All working solutions were pre- grade and redistilled water (RD H2O) was used in pared by de-ionized water. The respective metal con- preparation and dilution of all the solution. HNO3 were centrations were determined from each of the corre- procured from E. Merk, Germany. 1000 ppm spectral sponding calibration curves. Anallyttiicall CHEAMn IIndSianT JoRurnYal ACAIJ, 13(3) 2013 Jewel Das et al. 121 Full Paper RESULT AND DISCUSSION Bakarkhani and Cake samples contain 29%, 18% and 16 % moisture respectively while other bakery items The amount of essential and toxic metals in bakery contain less than 5%. Consequently metal content were foods is shown in TABLE 2 & 3. As wheat flour is the found higher in most of the analyzed bakery items rather common ingredient for all types of bakery foods which than Bread, Bakarkhani and Cake. The magnesium forms the foundation of most of the bakery foods and (Mg) levels in the samples varied from 35.55 mg kg-1 in -1 gives the structure to the product, two different brands round cake (C4) to 593.26 mg kg in chanachur (H2) white flour were analyzed for comparison. Bread, (TABLE 2). TABLE 2 : Amounts (mg kg-1) of K, Mg, Ca, Fe, Zn in bakery food products of Chittagong city area -1 ± SD Sample No. of Sample Metal Content (mg kg ) Type Sample (n) Code No. K Mg Ca Fe Zn ±0.013 ±0.794 ±0.885 ±0.030 ±0.010 A1 12.91 198.59 63.21 3.78 3.23 ±0.084 ±0.193 ±0.294 ±0.036 ±0.010 A2 16.72 96.67 73.41 1.01 1.02 ±0.040 ±0.17 ±0.123 ±0.038 ±0.004 Bread 5 A3 13.41 85.55 1 20.50 4.81 4.28 ±0.069 ±0.339 ±0.266 ±0.012 ±0.026 A4 23.08 169.41 22.19 4.04 5.14 ±0.047 ±0.242 ±0.711 ±0.030 ±0.007 A5 23.43 120.97 101.58 3.75 3.46 ±0.008 ±0.257 ±0.118 ±0.034 ±0.014 B1 8.13 85.77 23.69 2.00 1.73 ±0.00 ±0.296 ±0.058 ±0.016 ±0.010 B2 2.18 4 98.56 4.86 1.95 1.43 Bakarkhani 4 ±0.007 ±0.521 ±0.117 ±0.041 ±0.012 B3 7.18 130.33 39.02 2.96 1.73 ±0.010 ±0.167 ±0.045 ±0.022 ±0.015 B4 5.5 108.95 19.95 2.20 1.25 ±0.573 ±0.248 ±0.295 ±0.078 ±0.006 C1 114.51 124.02 42.19 12.94 6.26 Chocolate Cake 2 ±0.140 ±0.142 ±0.206 ±0.052 ±0.005 C2 85.5 118.55 38.50 13.55 3.68 ±0.056 ±0.242 ±0.198 ±0.035 ±0.009 C3 75.5 55.80 31.60 12.50 4.58 ±0.178 ±0.181 ±1.044 ±0.074 ±0.089 C4 69.83 35.55 34.38 10.48 5.00 Round Cake 4 ±0.811 ±0.076 ±0.418 ±0.11 ±0.018 C5 81.1 76.15 41.81 11.02 0 5.99 ±0.461 ±0.343 ±0.439 ±0.090 ±0.021 C6 65.5 65.85 35.55 9.75 4.50 ±0.234 ±0.159 ±0.355 ±0.044 ±0.018 C7 88.9 90.35 130.50 10.60 5.24 Custard Cake 2 ±0.275 ±0.143 ±0.285 ±0.036 ±0.011 C8 76.85 68.55 39.95 8.95 6.93 ±0.422 ±0.281 ±0.238 ±0.083 ±0.013 D1 84.46 93.66 29.71 6.88 4.42 ±0.171 ±0.114 ±0.368 ±0.172 ±0.013 Horlicks Biscuit 3 D2 85.73 56.76 30.69 11.45 4.21 ±0.061 ±0.210 ±0.102 ±0.022 ±0.017 D3 61.34 105.16 34.14 7.18 2.17 ±0.488 ±0.662 ±0.167 ±0.081 ±0.011 F1 162.62 165.59 41.70 8.95 5.37 ±0.040 ±0.624 ±0.199 ±0.028 ±0.009 F2 40.3 124.89 28.38 9.36 2.18 ±0.299 ±0.098 ±0.500 ±0.149 ±0.044 F3 59.73 97.70 38.50 29.71 14.80 ±0.158 ±0.106 ±0.168 ±0.027 ±0.009 Bela Biscuit 7 F4 32.55 78.85 26.55 10.50 2.58 ±0.234 ±0.089 ±0.232 ±0.016 ±0.011 F5 36.45 85.14 23.54 12.85 1.98 ±0.166 ±0.082 ±0.155 ±0.009 ±0.014 F6 38.55 76.35 19.58 13.55 4.50 ±0.198 ±0.205 ±0.225 ±0.015 ±0.008 F7 37.55 86.85 25.50 18.50 1.65 ±0.261 ±0.192 ±2.215 ±0.067 ±0.019 G1 130.74 96.09 138.06 33.47 6.19 Milk Marie Biscuit 2 ±0.432 ±0.372 ±0.4 ±0.111 ±0.018 G2 71.97 123.91 46.59 19 18.54 4.52 ±0.502 ±1.159 ±0.133 ±0.095 ±0.026 H1 100.49 579.37 33.31 23.72 13.11 ±0.267 ±1.187 ±1.167 ±0.035 ±0.042 H2 89.07 593.26 97.27 17.61 10.52 ±0.616 ±1.586 ±0.103 ±0.080 ±0.019 H3 87.99 528.71 34.30 16.09 9.40 ±0.325 ±0.789 ±0.023 ±0.011 ±0.012 Chanachur 7 H4 94.52 570.15 28.52 14.53 8.43 ±0.452 ±0.856 ±0.024 ±0.008 ±0.009 H5 89.85 540.65 31.52 24.58 9.12 ±0.455 ±0.848 ±0.015 ±0.032 ±0.014 H6 78.95 520.55 45.55 17.58 10.25 ±0.345 ±1.009 ±0.008 ±0.045 ±0.021 H7 92.25 496.50 33.56 23.50 8.25 Anallyttiicall CHEAMn InIdSianT JoRurnYal 122 Evaluation of essential and toxic metals .in bakery foods consumed in Chittagong ACAIJ, 13(3) 2013 Full Paper -1 ± SD Sample No. of Sample Metal Content (mg kg ) Type Sample (n) Code No. K Mg Ca Fe Zn ±0.687 ±0.278 ±0.057 ±0.171 ±0.018 I1 114.47 138.83 7.15 19.05 8.87 Toast Biscuit 2 ±0.465 ±0.151 ±0.033 ±0.078 ±0.016 I2 90.55 122.85 9.46 21.50 6.58 ±0.140 ±0.101 ±0.184 ±0.055 ±0.025 I3 46.52 101.12 18.42 10.92 2.73 Butter Toast 2 ±0.009 ±0.089 ±0.115 ±0.046 ±0.020 I4 48.43 96.58 14.12 9.55 2.55 ±1.805 ±0.815 ±0.103 ±0.061 ±0.036 E1 106.17 203.78 25.79 20.39 8.95 Wheat flour 2 ±1.204 ±0.367 ±0.336 ±0.07 ±0.008 E2 133.8 91.66 42.05 14.44 2 7.58 SD indicates standard deviation of three replicate measurements The concentration of Mg in most of the samples transport, cell division and growth[16]. Bone mineral was found higher than the other essential metals. Mag- serves as the ultimate reservoir for the calcium circulat- nesium is a critical co-factor in more than 300 enzy- ing in the extracellular fluid (ECF)[17]. matic reactions in the human body[11]. Magnesium defi- The recommended daily allowance (RDA) of Mg, ciency can affect virtually every organ system of the Fe, K, Ca, Co, Cu and Zn are shown in TABLE 4. body. With regard to skeletal muscle, one may experi- Zinc (Zn) concentration of was found 1.02 mg kg-1 in -1 ence twitches, cramps, muscle tension, muscle sore- bread (A2) to 14.80 mg kg in bela biscuits (F3). ness, including back aches, neck pain, tension head- The mean concentration of Zn was found maximum aches and jaw joint (or TMJ) dysfunction[12]. The low- in chanachur. Zinc enhances the stereo selectivity of the est and highest content of iron (Fe) were found 1.01 polymerization of nucleotides under reaction conditions -1 -1 mg kg for bread (A2) and 33.47 mg kg in milk marie designed to simulate the environment for prebiotic re- [16] biscuit (G1) respectively. In humans, iron is an essential actions . Zinc functions as a component of various component of proteins involved in oxygen transport. It enzymes in the maintenance of the structural integrity of is also essential for the regulation of cell growth and proteins and in the regulation of gene expression[14]. The differentiation. A deficiency of iron limits oxygen deliv- highest value of Copper (Cu) was found 5.14 mg kg-1 ery to cells, resulting in fatigue, poor work performance, in horlicks biscuits (D1) and lowest value was found -1 and decreased immunity. On the other hand, excess 0.05 mgkg in bread (A2) (TABLE 3). amounts of iron can result in toxicity and even death[13,14]. Although Cu is essential element in trace amount The concentration of potassium (K) in the different bak- but can be toxic when it exceeds the maximum permis- ery foods ranges from 2.18 -162.62 mg kg-1. The high- sible limit. Cu serves as an antioxidant and helps the est level of K was observed in bela biscuit (F1) and body to remove free radicals, prevent cell structure lowest level was found in Bakarkhani (B2). Newer evi- damage and responsible for hyperactivity in autistic chil- dence suggests that dietary potassium may play a role dren. Many copper metalloenzymes have been identi- in decreasing blood pressure. Potassium is involved in fied in humans[14]. Cobalt (Co) were not detected at nerve function, muscle control and blood pressure. A the ppm level in all types of bakery food sample. The diet low in potassium and high in sodium may be a fac- manganese (Mn) levels in the sample varied from 1.34 -1 -1 tor in high blood pressure. Increasing potassium in the mg kg in baker khani (B2) to 9.62 mg kg in chanachur diet may protect against hypertension in people who (H1). Mn plays a critical role in oxygen evolution cata- are sensitive to high levels of sodium[15]. lyzed by the proteins of the photosynthetic reaction cen- The concentration of calcium (Ca) was found to be ter. Pyruvate carboxylase in mammals are also manga- 4.86-138.06 mg kg-1. The mean concentration of Ca nese protein[16]. Mn is involved in the formation of bone was above 21 mg kg-1 for all types of bakery food ex- and in amino acid, lipid, and carbohydrate metabolism. for adult men and cept toast and butter toast biscuits. Ca is essential for The Adequate Intake (AI) of Mn bone formation in children. Ca2+ ions are central to a women is 2.3 and 1.8 mg/day respectively[14]. complex intracellular messenger system that is mediat- Chanachur consists peanuts, chickpea flour, flattened ing a wide range of biological processes: muscle con- rice, palm oil, corn, chickpeas etc. as ingredients. The traction, secretion, glycolysis and glyconeogenesis, ion concentration of Mg, Zn, Mn and Ni were maximum in Anallyttiicall CHEAMn IIndSianT JoRurnYal ACAIJ, 13(3) 2013 Jewel Das et al. 123 Full Paper TABLE 3 : Amounts (mg kg-1) of Cu, Mn, Co, Ni, Pb, Cd and Cr in bakery food products of Chittagong city area

-1 ± SD No. of Sample Metal Content (mg kg ) Sample Type Sample (n) Code No. Cu Mn Co Ni Pb, Cd Cr ±0.009 ±0.024 A1 0.53 2.99 *** *** *** *** *** ±0.002 ±0.011 A2 0.05 2.17 *** *** *** *** *** ±0.001 ±0.008 Bread 5 A3 0.10 1.96 *** *** *** *** *** ±0.006 ±0.018 A4 0.33 2.96 *** *** *** *** *** ±0.004 ±0.045 A5 0.17 2.14 *** *** *** *** *** ±0.013 ±0.002 ±0.03 B1 0.37 2.09 *** 0.56 *** *** *** ±0.018 ±0.008 B2 0.30 1.34 *** *** *** *** *** Bakarkhani 4 ±0.001 ±0.017 ±0.02 B3 0.33 2.41 *** 0.49 *** *** *** ±0.009 ±0.013 B4 0.28 1.98 *** *** *** *** *** ±0.053 ±0.020 ±0.03 ± C1 1.15 2.51 *** 0.94 *** 0.28 0.03 *** Chocolate Cake 2 ±0.038 ±0.032 C2 0.96 2.35 *** *** *** *** *** ±0.002 ±0.015 C3 1.96 1.65 *** *** *** *** *** ±0.009 ±0. C4 2.24 2.03 039 *** *** *** *** *** Round Cake 4 ±0.008 ±0.027 C5 2.64 1.89 *** *** *** *** *** ±0.004 ±0.018 C6 1.78 1.75 *** *** *** *** *** ±0.007 ±0.009 C7 1.78 2.15 *** *** *** *** *** Custard Cake 2 ±0.010 ±0.022 C8 1.52 1.96 *** *** *** *** *** ±0.021 ±0.028 ±0.05 D1 5.14 2.76 *** 1.61 *** *** *** ±0.030 ±0.031 ±0.003 Horlicks Biscuit 3 D2 3.29 2.60 *** *** 0.06 *** *** ±0.058 ±0.038 ±0.011 D3 3.06 2.22 *** *** 0.27 *** *** ±0.015 ±0.059 F1 1.13 2.02 *** *** *** *** *** ±0.009 ±0.023 F2 0.45 3.27 *** *** *** *** *** ±0.012 ±0.023 F3 0.74 3.78 *** *** *** *** *** ±0.007 ±0.027 Bela Biscuit 7 F4 0.50 1.98 *** *** *** *** *** ±0.006 ±0.008 F5 0.55 2.85 *** *** *** *** *** ±0.004 ±0.017 F6 0.59 1.65 *** *** *** *** *** ±0.009 ±0.018 ±0.005 F7 0.35 2.15 *** *** 0.08 *** *** ±0.043 ±0.007 ±0.059 ± G1 2.55 6.90 *** *** 1.21 0.47 0.03 *** Milk Marie Biscuit 2 ±0.005 ±0.027 G2 1.02 2.98 *** *** *** *** *** ±0.010 ±0.010 ±0.10 ±0.022 ± H1 0.98 9.62 *** 1.94 1.10 0.10 0.02 *** ±0.030 ±0.063 ±0.10 H2 1.74 7.92 *** 2.94 *** *** *** ±0.007 ±0.039 ±0.08 ±0.004 ± H3 1.04 7.72 *** 1.26 0.16 0.13 0.04 *** ±0.010 ±0.026 ±0.04 ±0.003 Chanachur 7 H4 0.89 6.55 *** 0.98 0.13 *** *** ±0.008 ±0.042 ±0.07 ±0.010 H5 0.96 8.25 *** 1.12 0.10 *** *** ±0.008 ±0.045 ±0.04 ±0.006 ± H6 0.98 7.61 *** 0.96 0.09 0.08 0.01 *** ±0.007 ±0.027 ±0.08 H7 1.01 6.53 *** 1.08 *** *** *** ±0.006 ±0.002 ±0.017 I1 2.16 3.54 *** *** 0.49 *** *** Toast Biscuit 2 ±0.010 ±0.005 ±0.011 I2 1.95 3.15 *** *** 0.40 *** *** ±0.020 ±0.003 ±0.028 I3 0.57 2.86 *** *** 0.46 *** *** Butter Toast 2 ±0.011 ±0.006 ±0.021 I4 0.75 2.45 *** *** 0.30 *** *** ±0.033 ±0.016 E1 3.71 5.46 *** *** *** *** *** Wheat flour 2 ±0.070 ±0.007 E2 4.99 6.77 *** *** *** *** *** *** indicates below detection limit Anallyttiicall CHEAMn InIdSianT JoRurnYal 124 Evaluation of essential and toxic metals .in bakery foods consumed in Chittagong ACAIJ, 13(3) 2013 Full Paper TABLE 4 : Recommended daily allowance (RDA) value of the metals (mg / day) for an adult person[4,14]. Mg Fe K Ca Co Cu Zn RDA (mg/day) 310-400 8-18 4700 1000-1300 1-1.5 1.5-3.2 12-15 Chanachur and mean concentration of other metals also choice taking into consideration the heavy metal toxic- found satisfactory compare to flour which indicates it is ity effects. All bakery items are good source of macro a very good source of minerals. and micronutrients. Most of the studied food samples Ni, Pb and Cd were not detected at the ppm level are free from toxic metal contamination and little food in 72.5 %, 67.5% and 87.5% of analyzed bakery food stuff contains the toxic elements within consumable limit. sample respectively. Maximum value of Ni was 2.94 Moreover, concerned authority should take necessary mg kg-1 in chanachur (H2) while minimum was 0.49 mg steps for reducing the toxic metal contamination into kg-1 in bakar khani (B3). Both Pb (1.21 mg kg-1) and the food chain. This study also provided baseline data Cd (0.47 mg kg-1) was found maximum in milk marie on toxic metal concentrations for baker foods in this biscuit (G1) while minimum Pb was found 0.06 mg kg-1 region of Bangladesh. in horlicks biscuits (D2) and minimum Cd was found 0.08 mg kg-1 in chanachur (H6). The permisble limit of ACKNOWLEDGMENTS ìg g Ni is 4 -1 according to Food and Nutrition Board: Institute of Medicine, 2010[18]. The concentration of We are grateful to Bangladesh Council of Scienific ìg Pb if exceeding the maximum permissible limits (0.2 and Industrial Reasearch (BCSIR) and The Director of g-1) in human, affect nervous system, bones, liver, BCSIR Laboratories, Chittagong. pancreases, teeth and gum & causes blood diseases[19]. 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