VOL. 5, NO. 6, June 2015 ISSN ARPN Journal of Science and Technology All rights reserved.

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1 Quantitative Assessment of (Ca, Mg, K, Na, Fe, Mn) in Some Brands of Green Tea Marketed in Libya 1 Jamal A. Mayouf, 2 Hashim S. Al Bayati, 3 Eltayeb M. Emmima ABSTRACT Green tea is one of the most common drinks in Libyan. Elements contents such as Iron (Fe), Manganese ( Mn), Calcium (Ca), Magnesium (Mg) were determined in four green tea samples collected from Libyan market and their tea infusions by using Atomic Absorption spectrophotometer (AAS) after acid digestion, Potassium (K) and Sodium (Na) were determined in four green tea samples by Flame Photometer. The results obtained indicate that, the major concentrations of Fe, Mn, Ca, Mg, K, and Na in tea infusions samples were( 0.68), (6.87), (12.34), (6.95), (152.1), (15.19) mg/l after boiling for 5 min.; (0.68), (7.56), (30.06), (7.56), (148.7), (21.85) mg/l after boiling for 10 min.; (0.57), (7.48), (12.37),(6.95), (145.3), (14.44) mg/l after boiling for 15 min. respectively. On the other hand, the major concentrations of the same element mentioned above obtained in tea leaves were (454), (2260), (7468), (1426), (21700), (3550) mg/kg respectively. The highest value of percentages in the infusions was registered of K equaled to 50.0% in sample (2), however the lowest value was registered of Ca equaled to 4.5% in sample (1). Keywords: Green tea, tea leave, infusion, AAS, Flame Photometer. 1. INTRODUCTION Tea is classified in to three major categories according to the degree of fermentation: unfermented green teas, partially fermented oolong and paochong teas, and fully fermented black and pu-ert teas [1]. Tea leaves are source of mineral elements such as Manganese, Iron, Magnesium, Sodium, Potassium, Copper, Titanium, Zinc, Aluminum, Strontium, Bromine, iodine, phosphorus, and fluorine. The tea infusion contains very little protein, vitamins, and carbohydrate but may be a source of essential dietary metals and binding polyphenols [ 2]. [.Drying and roasting the leaves produces green tea; black tea in obtained after a fermentation process [ 3].Herbed tea is an infusion made from anything other than leaves of the camellia Sinensis,typically, it is the combination of boiling water and dried fruits, flowers or herbs [ 4].Tea is now drown all over the world but especially in India, Indonesia, Sri Lanka, and Japan.Tea is also successfully grown in Africa, namely in Kenya, Malawi, Zimbabwe and South Africa [5]. It grows best at lower temperatures (5-25 C 0 ), high relative humidity (80 90 %), and high annual rain full (around mm). It favors a deep, well-drained, and acidic soil [ 6].The concentrations of elements in soil are reflected in the elements of tea leaves [7-9 ] and when nutrients including elements are used in tea growth, about one month is required until the elements return to the original level [10]. Among the minerals and essential trace elements, Ca, Na, K, Mg and Mn are present in tea leaves at g/kg level, while Fe is present at mg/kg [ 11]. Iron, one of the most abundant metals on Earth is essential to most life forms and to normal human physiology. Iron is an integral part of many proteins and enzymes that maintain good health.in human metabolism; iron is an essential component of proteins involved in oxygen transport [ 12]. Deficiency of iron limits oxygen delivery to cells, resulting in fatigue, poor work performance, and decreased immunity. On the other hand, excess amounts of iron can result in toxicity and even death [ 13]. The total Fe and Mn concentrations in the tea leaves, and the a mounts of these elements available in the tea infusions were evaluated depending on the type of tea and on the method of preparation, more over the possible impact of the tea drinking of the uptake of these elements is discussed [14]. The preparation method (infusion time, temperature, tea-water ratio) has also a great influence [15]. For many people, tea drinking may be a major source of dietary Mn [ 16]. It is recommended to individuals with a high prevalence of iron deficiency to drink tea between meals, and to wait at least 1 hour after eating before taking tea [17]. In the present study, we collected commercial green tea leaves from four different production regions in local Libyan markets. 2. MATERIALS AND METHODS Four marked brands of green tea which commonly consumed in Libya were collected from local markets in 2014 (Table 1). Table 1: Analyzed tea samples No. of sample Name Origin Class 1 Al shanmi China green 2 Paroawd / China green Tour 3 Al Jawhara Egypt green 4 Adam Sri Lanka green Tea infusions were prepared to test the solubility of the metals after (a) 5 min, (b)10 min, (c)15 min as follows: 100 ml of hot distilled water was added to 2 g of sample.after the given time, tea infusion were lift to cool at room temperature for 2 min and then filtered through filter paper (Whatman No 42), then digested by added 3 ml of concentrated HNO 3 65% and 5ml conc. HCL 37%,the sample covered and heated on hot plate, the solution filtered and the infusion diluted to 100ml with deionized water. The phs of the tea infusions were determined potential metrically. Total contents of metals were determined by having a portions of 0.5 g of each brand were digested 303

2 using 10 ml of a mixture (2:1v/v) concentrated HNO 3 and HCL. The mixture was heated on hot plate,then the digest was transferred in to 100 ml volumetric flask after filtered (Whatman 42) and adjusted to the mark using distilled water Fe, Mn, Ca, Mg were measured by AAS, however, Na and K were measured by Flame Photometer. 3. RESULTS AND DISCUSSION Total contents of metals in tea samples are shown in( Table 2). Table 2: Total contents of metal (mg/kg) in green tea samples No. of sample Fe Mn Ca Mg K Na The contents of metals in the tea leaves can be arranged in the following order, with regards to their total contents: K>Ca>Na>Mn>Mg>Fe. However, the levels of metals in the infusions can be arranged in the following order; K > Na >Ca> Mg >Mn> Fe (Table 3). Table 3: Concentrations of metals in infusion (mg/l) of samples Element Infusion time Sample 1 (mg/l) Sample 2 (mg/l) Sample 3 (mg/l) Sample 4 (mg/l) Fe Mn Ca Mg K Na The percentage of easily hot water soluble forms of Fe, Mn, Ca, Mg, and, Na found in the tea infusions and related to their total contents in dry matter, can be arranged in the following order: K > Na > Mg >Mn>Ca>Fe (Table 4). 304

Table 4: Concentration of metals (mg/kg) and percentages in infusions of samples Element Sample Time 1 2 3 4 mg/k g % mg/k g % mg/k g % mg/k g % Fe Mn Ca Mg K Na 5 34 9.3 30 6.60 21.5 6.55 14 4.

5 16.5 5 490.5 10.1 485 8.6 379.5 7.2 617 8.3 10 569.5 11.8 387.5 6.8 332.5 6.3 1503 20.1 15 618.5 12.8 253 4.5 316.5 6.0 379.5 5.1 5 335 24.5 329.5 23.7 347.5 25.4 327.5 23.0 10 378 27.7 320 23.

3 Table 4: Concentration of metals (mg/kg) and percentages in infusions of samples Element Sample Time mg/k g % mg/k g % mg/k g % mg/k g % Fe Mn Ca Mg K Na Fe can be widely found in nature and is one of the most important elements in. environmental and biological systems as many kinds of compounds. Fe is essentially distributed in hem chrome that occupies (60-70) % of the total Fe in a body [18].. Fe is a necessary and useful element for organisms and a significant part of tissue and blood in animal and human bodies [19] Our study on tea leaves Fe levels found to be ( ) mg/kg and ( ) mg/l with a mean 0.47 mg/l in the infusion and percentages range of Fe was (4.29%- 9.30%) with a mean 6.41% (Table 2,3,4) and ( Figure 1) [14] reported Fe percentage in green tea infusions related to Fe contents in leaves were 1.5%, however, [20] reported Fe levels 460 mg/kg in leaves and (43.0, 38.0) mg/kg (5min, 10min) respectively in the infusions sample1 sample2 sample3 sample4 5min 10min 15min Fig 1: Concentration of Fe (mg/l) in infusions of samples according to three times 305

4 Manganese is present in all the tea leaves samples, ranging from 718 to 2260 mg/kg with a mean 1638 mg/kg in our study. However the value of Mn was found to be higher than those reported by [14] who reported a mean of Mn in green tea leaves samples 1123 was mg/kg. In our study, the levels mean of Mn in the infusions was 5.44 mg/l with a range of 2.37 to 7.56 mg/l, and percentages range was 13.5% to 18.7% with a mean16.73% (Table 2,3,4) and (Figure 2). High doses of dietary manganese can be associated with long-term toxicity. Therefore, an estimated safe and sufficient daily dietary intake is 2-5 mg [21]. Manganese (Mn) is an important element in many biochemical processes in plants and usually acts as an activator for different enzymes [22]. Fig 2: Concentration of Mn (mg/l) in infusions of samples according to three times Magnesium works with calcium to help transmitting nerve impulse in the brain. Both elements give relief in patients having depression [23]. Mg in the tea leaf samples with a mean of 1387 mg/kg, range of 1366 to 1426 mg/kg. Calcium, which is the most common mineral in the body, helps in the transport of long chain fatty acids, which aid in prevention of diseases, high blood pressure and other cardiovascular diseases. The obtained calcium levels are Ca in the tea leaves samples with a mean of mg/kg, range of 7468 to 4842 mg/kg. The results obtained in our study for Mg and were lower than reported by than those reported by [24]. Ca and Mg levels mean in the infusions were (10.47, 6.86) mg/l, range of 5.06 to mg/l and 6.40 to7.56 mg/l respectively. However, percentages range was (4.5 to 20.1 ) % and, ( 23.0 to 27.7) %, with a mean (8.96, 24.65) % of Ca and Mg respectively (Table 2,3,4) and (Figure 3,4). 306

Fig 3: Concentration of Mg (mg/l) in infusions of samples according to three times Fig 4: Concentration of Ca (mg/l) in infusions of samples according to three times Sodium is the major action in

5 Fig 3: Concentration of Mg (mg/l) in infusions of samples according to three times Fig 4: Concentration of Ca (mg/l) in infusions of samples according to three times Sodium is the major action in blood and extracellular fluid [25]. The levels of sodium in the tea leaf samples range from 2000 to 3556 mg/kg, with a mean of 2870 mg/kg, the value of Na was found to be higher than those reported by [26] who reported a mean of Na in tea plants leaves samples was 218 mg/kg. In our study, the levels mean of Mn in the infusions was Na levels in the infusions were to 21.85mg/l, with a mean of mg/l. The percentages range was 19.6 to 38.0% with a mean of 25.66% (Table 2,3,4) and (Figure 5). 307

Fig 5: Concentration of Na (mg/l) in infusions of samples according to three times Potassium is important for reducing blood pressure and also increasing blood circulation as well as preventative aid

The value of K was found to be higher than those reported by [26] who reported a mean of K in tea plants leaves samples was 112 mg/kg. K levels in the infusions were 128.20 to 152.

6 Fig 5: Concentration of Na (mg/l) in infusions of samples according to three times Potassium is important for reducing blood pressure and also increasing blood circulation as well as preventative aid on general health [27]. Potassium was the element with high content in all the tea samples analyzed with a mean of 18673mg/kg, and concentration ranging from to mg/kg. The value of K was found to be higher than those reported by [26] who reported a mean of K in tea plants leaves samples was 112 mg/kg. K levels in the infusions were to mg/l, with a mean of mg/l. The percentages were 32.8 to 50.0 % with a mean of % (Table 2,3,4) and (Figure 6). Fig 6: Concentration of K (mg/l) in infusions of samples according to three times The concentrations of Fe, Mn, Ca, Mg, K, and Na in tea leaves samples were higher than Prevention of Food Adulteration (PFA) limit and World Health Organization (WHO) permissible limit. However, the concentrations of metals in the infusions were as the following ; Fe and Mn were higher than permissible limits reported by (WHO 1998a,b) [28][29], Ca, Mg,K, Na were in agreement with limits (WHO). 308

The ph s of green tea infusions were in the range 5.58 of 5.19 (average value) 5.35 these results were higher than results which reported by [14] who reported a mean of 4.

7 The ph s of green tea infusions were in the range 5.58 of 5.19 (average value) 5.35 these results were higher than results which reported by [14] who reported a mean of 4.5 of green tea infusions (Table 5) and (Figure 7). ph Table 5: Values of ph in green tea infusions Infusion time Sample 1 Sample 2 Sample 3 Sample Fig 7: Values of ph in green tea infusions of samples 4. CONCLUSION Concentration of Fe was lesser than other metals (Ca, Mg, Na, Mn and K) in total content infusions and percentages, however concentration of K has higher value than other metals. The percentages which released from total contents of metals in green tea samples were different; in samples 2 & 3 showed decreased in the percentages according to 5 min toward 15 min however, the sample 1 reported increased in the percentages according to 5 min toward 15 min. REFERENCES [1] Xie, G.; Ye, M.; Wang, Y.; Ni, Y.; Su, M.; Huang, H.; Qiu, M., Zhao, A.; Zheng, X.; Chen,T.; Jia, W. J. Agric. Food Chem. 2009, 57, [2] Fiedman, M., Overview of antibacterial, antitoxin, antiviral and antifungal activities of tea flavonoids and tea.mol. Nutr. Food Res. 51, [3] Gorur, F.K.; Keser, R.; Akçay, N.; As, N.; Dizman, S. Iran J. Radiat. Res. 2012, [10] 67. [4] Chan, E.W.C.; Lim, Y.Y.; Chong, K.L.; Tan, J.B.L.;Wong, S.K. J. Food Comp. Anal. 2010, 23,185. [5] GREENOP J. (1997): The Life style Food Index for South African Consumers. Demeter Publications, Gauteng, South Africa. [6] MUSGRAVE T. (2002): Empire of Plants. Cassel, New York. [7] Fernandez-Caceres,p.L., Martin M.J., palos F., Gonzaleze,G. (2001) Different of tea ( Camellia sinensis)varieties and their metal content. J. Agric. food chem...49; [8] Uchimura, K, Katsuda, M., Miura, N. (2007) Determination of the geographical origin in different soil parent materials of tea with inorganic element composition.chopakenkyuhoukoku 103; (in Japanese). [9] Jalbani, N., Kazie, T. G.,Arami, Bm., Jamali, M. K, Afridi, H.I.(2007).Evaluation of total contents of 309

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Determination of the concentration of caffeine, theobromine, and gallic acid in commercial tea samples

Determination of the concentration of caffeine, theobromine, and gallic acid in commercial tea samples Janna Erickson Department of Chemistry, Concordia College, 901 8 th St S, Moorhead, MN 56562 Abstract