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Suitability of water for food processing in Khartoum national industrial zone

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https://www.eduzhai.net Food and Public Health: 2011; 1(1): 11-15 DOI: 10.5923/j.fph.20110101.03 The Suitability of Water in Khartoum State Industrial Area for Food Processing Abdel Moneim E. Sulieman1,*, Batran E. El Hilali1, Mohammed O. Babekir2 1Department of Food Science and Technology, Faculty of Engineering and Technology, University of Gezira, Wad-M edani, Sudan 2Department of Applied Chemistry and chemical Technology, Faculty of Engineer ing and Technology, University of Gezira, Wad-M edani, Sudan Abstract The present study aimed at investigating the suitability of water for food processing particularly gaseous bev- erages in Khartou m State. Ten samples of water were co llected fro m six wells (A, B, C, D, E and F) distributed throughout Khartoum North Industrial Area, also three samp les (T1,T2,T3) were collected fro m well (B) after water treat ment. The p H of water samples ranged (6.7 – 7.8). All samp les gave acceptable results for the Electrical Conductivity (E.C) (284– 970µs/cm, total dissolved solids (T.D.S) (143 – 485 mg/ L), sulfate (1.5 – 142.4 mg/ L), chloride (6.8–94.0mg/ L), fluoride (0.0–0.23 mg/ L), n itrate (2.01 – 9.24 mg/ L), n itrite (0.006–0.467 mg/ L), As for ammonia the collected water samples contained a range of (0.0 – 0.01mg/ L), wh ile the iron content of the various water samples was ≤0.3 mg/ L. So me of the samples gave high levels of turb idity while other samples gave low levels of turbid ity. The water samp les were free fro m E. coli and the total colifo rm, therefore they were acceptable for the consumer and were suitable for drinking and food processing as they have matched with all conditions of the Sudanese Standards and the International Standards for drin king water. The T.D.S of water samp les ranged between 143-260 m/ l. This indicates that there is no need fo r using Reverse Osmosis (R.O) to reduce the concentration of the salts and minerals in water. Filtration and coagulation process for the water treatment is sufficient process for this purpose. Most of the microbiological, physical, chemical and geological p roperties for well's water samples (A, B, C, D, E and F) , were found to match with the local and International Standards for drin king water, that means these water samp les are suitable for food processing and drinking. Keywords Food Processing, Chemical Examination, Microbiological Examination, Most Probable Nu mber Test 1. Introduction Water is of vital importance for human life. The body uses water for d igestion, absorption, circulation, transporting nutrients, building tissues, carrying away waste and monitoring body temperature. Drinking water, co mes fro m mun icipal water systems, wells or springs, and is treated to remove bacteria and other pathogens and most pesticides. The resulting water is purified but still contains some dissolved solids. Natural water comes fro m un protected well or spring system and is bottled without extensive treatment. Because it is almost exclusively groundwater, it usually contains a range of minerals and is, therefore, quite flavorful. Spring water is groundwater thathas risen naturally to the surface. Mineral water is simp ly water contains minerals, which is true of virtually all water except distilled water. Groundwater is that water wh ich flows out fro m the sub * Corresponding author: moneim_ug@yahoo.com (A. M. E. Sulieman) Published online at http://journal.sapub.org/fph Copyright © 2011 Scientific & Academic Publishing. All Rights Reserved surface of the earth at d ifferent depth. The groundwater found in Sudan at many locations with different format ions, according to the characteristic of the area and the geological formation. The slow percolation and horizontal travel at only a few feet a day through the ground is the superb filtration removing all pathogenic forms, including viruses, and removing the causes of color, turbidity, taste and odor (Elh ass an ,[1]. Water for drinking and food preparation must be free from organisms capable of causing diseases, and from minerals and organic substances producing adverse physiological effects (The A merican Water Works Association[2]. The objectives were: To evaluate some of the microbiological, physical and chemical characteristics of water samples collected fro m Khartoum North industrial area. To compare the various physical, chemical and microbiological characteristics of water samples with the local and International Standards for drinking water. To evaluate the suitability of these water samples for using in food industry. 2. Materials and Methods 12 A. M . E. Sulieman et al.: The Suitability of Water in Khartoum State Industrial Area for Food Processing 2.1. Study Area The study area lies entirely in North part of Khartoum State. The area is located between latitude 15˚.39" and 15º.59"N and longitude 32º.33" and 32º.50" E. Climate of the area is hot in summer and the temperature in this season varies between (17-45o C) in the year. In the study area there are many food factories, they use water for t wo major purposes, (i) for washing and cleaning the machines and equipment, and (ii) for processing. The food factories in the study area included: dairy factory, confectionary factory, paste factory, mineral water and ju ice factory, biscuit and Taheneya factory. The water used in some of there factories e.g. soft drink factory is purified by filters sand and carbon, or treated with Reverse Osmosis (R.O) and ultra violet sterilization (U.V), however, in mineral bottled water production, ozone is used instead of U.V However in some factories, the coagulation process (by using the reaction tank) is used instead of R.O system for alkalinity reduction. 2.2. Sampling Samples of water were collected during the period (October to December 2008) fro m six wells namely (A,B,C,D,E and F) distributed throughout Khartoum North Industrial A rea, also three samples (T1,T2,T3) were collected fro m well (B) after water treat ment. Co llected water samples we re immediately transported without ice in sterile bottles to the laboratory of Microbiology, Facu lty of Agriculture Khartoum University and Khartoum State Water Corporation Central laboratory (microbio logy and chemically) and examined directly. In addition to the previously mentioned samples, bottled water samples were co llected fro m Khartoum local market to be used as control. 2.3. Chemical Examinati ons 2.3.1. Total Dissolved Solids (TDS), Electrical Conductivity (E.C) and pH The total dissolved solids (TDS), electrical conductivity (E.C) and pH were determined by pH meter (Hanna-instrument, model No. H 19811-5). 100 ml o f bottled water sample were placed in a beaker, then a glass electrode was inserted in the sample, and the results were recorded directly. 2.3.2. Determination of M inerals and Mineral Salts The minerals and mineral salts present in the ash as metallic o xides, were converted to chlorides by HCl and diluted. Flame Atomic Absorption Spectrophotometer (FAAS) with a variant spectrometer (SPECTR AA-10) was used to determine calciu m, magnesiu m and sodium according to APHA[4]. The mineral salts were also determined using standard methods. The mineral salts included: ch loride, nitrate, sulphate, nitrite and ammonia. The concentrations of all elements were expressed in ppm. 2.4. Microbi ological Exami nation Two techniques are commonly used for enumeration of total coliform, Feacal colifo rm and Feacal streptococci. The first of these is called the mult iple fermentation tube or most probable technique (we used this technique) and the second one is memb rane filtrat ion technique. 2.4.1. Co lony Count Total viable count was carried out using the pour technique as described by Harrigan and Mac Cane {5}. 10 ml of each sample was transferred to 90 ml o f sterile diluents, as a first dilution 10-1, serial dilutions were made up to 10-6 and 1 ml of each d ilution was transferred aseptically in duplicate into Petri-dishes. 10-15 ml melted plate count agar (45 – 46℃) was poured into the dishes. The dishes were then thoroughly mixed to facilitate distribution of the samp le throughout the mediu m, the mediu m was allowed to solidify and plates were incubated at 37℃ fo r 48 hours. Colony counter (Labtech) and hand – tally were used for the determination of the total bacterial counts in terms of colony forming units per ml (C.F.U/ ml). 2.4.2. Most Probable Nu mber Test Most probable number test was carried out according to Christopher[5], a measured portion of water sample was placed in test tubes containing a culture mediu m. The tubes were then incubated for a standard time at a standard temperature; the tubes also contained a small inverted glass tube (Durham tube) to facilitate the detection of gas production. This test comprised three steps:- Presumptive test. Confirmed test. Co mpleted test. a) Presumptive test:The mu ltiple tube fermentation technique was performed as a presumptive test for total coliform using tubes containing MacCane broth and inverted Durham tubes. Inoculation was carried out as follows:To each of 3 double – strength MacCane broth tubes, 10 ml o f the orig inal sample was added. To each of 3 double – strength MacCane broth tubes, 1 ml of the original samp le was added. To each of 3 double – strength MacCane broth tubes, 0.1 ml o f the orig inal sample was added. All tubes were incubated at 37oC for 48 hours for the observation of gas production. First reading was taken after 24 hours to record positive tubes, and the negative ones were incubated for another 24 hours. b) Confirmed test:Each gas positive presumpt ive tube was inoculated into a tube containing 10 ml brilliant green lactose broth mediu m. All tubes were incubated at 37o C for 48 hours for the observation of gas production. c) Co mpleted test:At least 3 loopful of each confirmed positive tube were subculture into EC b roth mediu m and then incubated at 44.5℃ fo r 24 hours. Tubes showing any amount of gas production were considered as positive and the probable Food and Public Health: 2011; 1(1): 11-15 13 number was recorded (the results were compared with the most probable number Table), (Christopher[5]. 2.4.3. Yeasts and Moulds Using spreading plate count method, potato dextrose agar was used for detection of yeasts/moulds, using the serial dilutions fro m each samp le. 0.1 ml fro m each dilution was taken; incubation was at 28oCfor 72 hours. 2.4.4. Feacal Streptococci Test Azide dextrose broth was used for the enumerat ion of Feacal streptococcus; tubes were incubated at 35℃ and checked for turbidity after 48 – 72 hours. These dilutions were used (10-1, 10-2, 10-3), fro m each dilution 3 tubes were prepared, and then results were recorded and co mpared with the most probable number Table. 3. Results and Discussion 3.1. Chemical Anal ysis of Water Samples The chemical analysis of water samples collected fro m the different wells in industrial area is shown in Tab le (1). A ll samples of water had pH in the range (6.7 – 7.8) which is acceptable according to (SSM O – 044 –[6] for drinking water; which indicated that level of pH wh ich is acceptable must be in the range of (6.5 – 8.5), and high levels of mo re than 8.5 can make a soda taste on the water and according to standards water must be odorless, colorless and tasteless. Well "B" gave a lo w result of p H (6.7) and that refer to formation of aquifer as in Table (1). As shown in Table (1) the water gave acceptable results for the electrical conductivity (E.C) in the range (284– 970µs/cm), which is acceptable according to (SSMO – 044 –[7] for drin king water. In addition, water samples of water had total dissolved solids (T.D.S) in the range (143 – 485 mg/L) which is acceptable according to (SSM O – 044 –[6] for d rin king water. Well "A" recorded a high level (485 mg/ L) of T.D.S and that refer to format ion of aquifer. The collected water samp les gave acceptable results for the sulfate which was in the range (1.5 – 142.4 mg/ L) that is acceptable according to (SSM O – 044 –[6] for drinking water. The high level of sulfate (142.4 mg/ L) recorded in Well "A" refer to the formation of aquifer. High levels of sulfate is not recommended since it can cause damage to p ipe work, gives rise to corrosion of steel, iron and aluminu m, however, due to the action of sulfate it is worth mentioning to indicate that the permissible level of sulfate is (250mg/ L) according to (SSMO – 044 –[6]. The chloride content in the different samp les ranged between (6.8–94.0mg/L) which is acceptable according to (SSM O – 044 –[6] fo r drinking water. It is known that high levels of chloride above 150mg/ L is also not recommended as it can cause damage to p ipe work, gives rise to corrosion of steel, iron and alu minu m. Table (1) also indicates acceptable results for the fluoride in water samples which ranged (0.0–0.23 mg/ L), however, this range is considered acceptable according to (SSMO – 044 –[6] for drin king water. It is known that high levels of fluoride above 1.5 mg/ L may cause problems for consumers like spots of skin and brown ing of teeth (SSMO – 044 –[6]. As for nitrate, it was found that in the range of (2.01 – 9.24 mg/ L). for drinking water. High levels of nitrate above 50 mg/ L can cause serious health problems for pregnant women and infants under the age of 6 months. The nitrite content ranged between (0.006–0.467 mg/L), which is acceptable according to (SSMO – 044 –[7] for drinking water, however high levels of nitrite above 2mg/L also causes serious health problems for pregnant women and infants by combining with some of the hemoglobin in blood to form methemoglobin that can not transport oxygen. The ammonia content in the collected water samples had a range of (0.0 – 0.01mg/ L), which is acceptable according to (SSM O – 044 – [6] fo r drinking water. Table 1. Chemical charact erist ics of Well's wat er Well pH No. E.C (µs/cm) T.D.S (m g /L) Nitrate (m g /L) Sulfate (m g /L) Chlo ri de (m g /L) Flu ori de (m g /L) Nitrite (m g /L) Ammonia (m g /L) A 7.5 970 485 9.24 142.4 94.0 0.23 0.467 0.0 B 6.7 284 143 4.4 1.5 8.0 0.19 0.017 0.0 C 7.5 311 155.2 3.96 14.7 6.8 0.16 0.009 0.0 D 7.53 294 146 4.04 14.7 7.0 0.12 0.007 0.0 E 7.58 287 143.4 4.84 14.6 10.0 0.0 0.006 0.0 F 7.8 381 260 2.01 36 14 0.0 0.01 14 A. M . E. Sulieman et al.: The Suitability of Water in Khartoum State Industrial Area for Food Processing 3.2. Physical and Chemical Anal ysis of Treated Water Samples As shown in Table (2) the appearance gave clear result in all samples and refers to resource (ground water). Samp le (T) gave a high level of turbidity (2.2 NTU), this could be attributed to the absence of filtrat ion unit (sand, carbon filter and R.O unit). In contrast, sample (T2) gave a low level (0.3 NTU) because of presence of sand and carbon and membrane. It is recognized that high level of turbidity mo re than 5NTU can affect the appearance of the water and can protect micro -organism fro m the effect of the disinfection and stimulates the growth of bacteria, and gives rise to a significant chlorine demand. Samp le (T1) recorded h igh level of T.D.S (165 mg/ L) and this refer to storing. However, sample (T3) recorded a value (102.7 mg/L) it was in the range of (SSMO – 044 –[6]. Table 2. Physical and chemical characteristics of treated water samples Paramete r T T1 T2 T3 Unit Appearance Clear Clear Clear Clear Turbidity Color Odor PH Temp erat ure E. Conductivity T.D.S T.Alk alin it y Total Hardness Sodium (Na) Chloride (Cl) Sulfate (SO4) Nitrite (NO2) Nitrate (NO3) Calcium (Ca) Magnesium (Mg) Fluoride (F) 2.2 Nil Nil 6.7 30 284 143 140 120 16.4 8 1.5 0.017 4.4 25.6 13.44 0.19 1.6 Nil Nil 6.7 28.9 330 65 60 140 16.4 16 1.5 0.05 4.4 30.4 15.63 0.22 0.3 Nil Nil 6.7 28.8 174.2 87.1 85 80 10.7 10 1.5 0.012 5.7 15.5 9.6 0.25 0.9 Nil Nil 6.7 27.4 205 102.7 100 84 14.2 12 1.5 0.01 4.4 17.6 9.6 0.11 NT U T CU C0 µ s/cm Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L Mg/L T: Bore hole water sample; T1: water sample after Carbon filter ;T2: water sample after R.O system; T3: water sample for Blended (T1 +T2). As shown in Table (2) sample (T1) gave high level of total hardness (140 mg/ L) and that refer to accu mulation of other water (with high total hardness) during storing period at storage tanks and also due to addition of chlorine for chemical t reat ment. Sample (T1) recorded high level o f magnesium (15.63 mg/ L) and this refers to storing. However, samp le (T3) recorded a value of (9.6 mg/L), wh ich falls within the range of (SSM O – 044 – [6]. 3.3. Microbi ological Analysis of Wellś Water As indicated in Table (3), Khartoum North Industrial Area wells samples were free fro m E. coli and the total coliform, therefore they were acceptable for the consumer and were suitable for drinking, because they matched with all conditions of the Sudanese Standards and the International Standards for drinking water (WHO,[7]. Table 3. Microbial Load of Wellś water samples (c.f.u/ml) Analysi s Wells T.V.C T.col F.col F.stre pt A Less t han 30 colonies in 10-1 _ _ _ B Less t han 35 colonies in 10-1 _ _ _ D 3.7×102 _ _ _ F 4.0×102 _ _ _ E 1.2×103 _ _ _ C 2.1×103 _ _ _ * No growth for yeasts and moulds in Table (3) samples. - ≡ Negative. T.V.C ≡ Tot al Viable Count . T.Coli ≡ Total Coliform. F.Coli ≡ Feacal Coliform. F.St rept ≡ Feacal Strept ococci. These standards stated that all water intended for drinking must be free fro m E. coli or total coliform bacteria in any 100 ml of water sample. When comparing these results with some studies carried before (Ah med,[8], samples which had been taken from different cisterns of selected food factories at industrial area North Khartoum and analyzed for total colifo rms, feacal coliforms and feacal streptococci using two techniques (MPN and MF), found that 60% of the total samples showed the detection of total coliform by the MPN technique whereas the MF technique detected them in 52% of the total samples. And when comparing the two techniques on the basis of feacal coliform, the MPN technique detected feacal coliform in 55% o f the total samples whereas the MF technique detected them in 45% of the total samples . For feacal streptococci in detection, the MPN technique detected 30% of the total samp les whereas the MF technique detected 26.7% of the total samp les. The absence of total colifo rm and Feacal coliform and Fecacal streptococci in wells samp les refer to good cementing and good design of wells . As indicated in Tab le (4) there was no presence of total colifo rm and total count and that refer to adequate treatment or good sterilization procedure. Table 4. Microbiological characteristics of treated Wellś water No. Location Total Coliform/100 Total Count ML Colony/5 ML 1 T1 Zero _ 2 T2 Zero _ 3 T3 Zero _ 4 T4 Zero _ No growth for yeasts and moulds T1: After carbon filteration. T2: After R.O unit. T3 : Blending.(T1+T2). T4: Local market sample. Food and Public Health: 2011; 1(1): 11-15 15 4. Conclusions Based on the results, the T.D.S of water samp les taken fro m various wells (A, B, C, D, E and F) in Khartoum North industrial area ranged between 143-260 m/ l. This indicates that there is no need for using Reverse Osmosis (R.O) to reduce the concentration of the salts and minerals in water. Filtration and coagulation process for the water t reatment is sufficient process for this purpose. The proper wells design reduces the microorganism contamination and water treat ment costs. Most of the microbio logical, physical, chemical and geological properties for well's water samp les (A, B, C, D, E and F) , were found to match with the local and International Standards for drinking water, that means these water samples are suitable for food processing and drinking. Based on the results of various analyses, the followings can be recommended: To encourage using (U.V) system for treat ment of water because this system is efficient and safe. Proper wells design is recommended since it reduces the microorganis m contamination and water treat ment costs. Further studies are needed to verify using treatment methods other than (R.O) system as it is very expensive. REFERENCES [1] Elhassan, B.M . (2006). Workshop Applied techniques for water and waste water quality control, National center for research environment and natural resources research institute, 21-26 January, Khartoum, Sudan. [2] American Water Work Association (1971). Water quality treatment 3rd edition U.S.A. [3] A.P.H.A (1980). American Public Health Association. Standard M ethods for the Examination of Water and Waste. [4] Harrigan, W.F. and M acCance, M .E., (1976). Laboratory M ethods in M icrobiology, pp. 257-303 Academic Press, London and New York . [5] Christopher, R.; Sechul, Z. and Daniel A. Okun, (1981), Surface Water Treatment for Communities in Developing Countries. [6] SSM O-044, (2007). Sudanese Standard and M etrology Organization [7] WHO, (1997). Guidelines for drinking water quality 2nd edition volume 3, surveillance and control of community supplies, World health organization, Geneva. ACKNOWLEDGEMENTS [8] Ahmed, I.F. (2005). M icrobiological Quality of Water in Some Food Facilities Storage Cisterns in Khartoum North This work forms part of a research carried out at the Food Industrial Area Ph.D. Thesis, Univ. of Khartoum, Sudan .p 54-60, 20-32. Science and Technology, Gezira University, Sudan. The authors express their sincere thanks to all staff members, techniques and the colleagues for their assistance.

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