BIBECHANA Vol. 21, No. 3, December 2024, 321-327 ISSN 2091-0762 (Print), 2382-5340 (Online) Journal homepage: http://nepjol.info/index.php/BIBECHANA Publisher: Dept. of Phys., Mahendra Morang A. M. Campus (Tribhuvan University) Biratnagar pH profile and acidity analysis of some Nepalese tea brands: effects of tea type and temperature Narendra Kumar Chaudhary∗, Sanjaya Thakur, Sujan Budhathoki, Dipak Baral Department of Chemistry, Mahendra Morang Adarsh Multiple Campus, Biratnagar, (Tribhuvan University) Nepal ∗Corresponding author: Email: chem_narendra@yahoo.com Abstract Tea is a popular beverage enjoyed throughout the world, often as a morning wake-up drink. However, excessive consumption may negatively affect health, especially for those who suffer from acidity. In this study, we report the pH values of four locally available tea brands, Tokla, Ridhisidhi, Suman, and Muna, brewed at cold and hot conditions and flavored with lemon juice as an additive to determine how conditions and additives affect acidity. Hot-brewed tea had an alkaline pH range of 7.74 to 9.03, while cold-brewed tea had a reduced pH range of 7.12 to 7.23. The pH value of lemon-flavored tea ranged from 4.59 to 6.98, suggesting that its acidity may cause problems for those who are sensitive to acid. Milk-based teas exhibited pH values between 6.07 and 7.4, while teas with added sugar had lower pH values. With increasing sugar concentrations, tea becomes more acidic. According to these findings, plain black tea is preferable for individuals who are sensitive to acid, whereas lemon-flavored tea may be uncomfortable for them. Studying the acidity levels of Nepalese tea can therefore provide valuable information about its potential health benefits. In turn, this could lead to research on how brewing techniques and ingredients affect tea chemical composition. Keywords Tea, pH value, acidity, lemon tea, health benefits, flavor. Article information Manuscript received: August 20, 2024; Revised: October 1, 2024; Accepted: October 3, 2024 DOI https://doi.org/10.3126/bibechana.v21i3.68944 This work is licensed under the Creative Commons CC BY-NC License. https://creativecommons. org/licenses/by-nc/4.0/ 1 Introduction Tea is a popular beverage worldwide, and millions of people enjoy it every day because of its refreshing taste, multiple flavors, and numerous health bene- fits [1]. Tea, derived from the leaves of the Camellia sinensis plant, is not only consumed as a daily bev- erage but also holds significant cultural importance, varying across regions and spanning thousands of years of history [2]. Chinese emperor Shen Nong accidentally discovered tea around 2737 BCE when some tea leaves fell into boiling water [3]. Since then, tea has spread globally, becoming an integral part of various cultures [4]. Each culture has devel- 321 http://nepjol.info/index.php/BIBECHANA chem_narendra@yahoo.com https://doi.org/10.3126/bibechana.v21i3.68944 https://creativecommons.org/licenses/by-nc/4.0/ https://creativecommons.org/licenses/by-nc/4.0/ Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 322 oped unique traditions and rituals for its consump- tion [5]. Tea consumption is an essential part of Nepalese culture and economy, with several local brands pro- ducing high-quality tea [6]. The hilly region of Nepal has a suitable climate, fertile soil, and abun- dant water, making it an ideal location for tea plan- tations (Figure 1). The tea produced in this region is of high quality and renowned for its flavor, con- tributing to popularity of hills growing popularity as a destination for tea tourism. The pH of tea is an important factor that can influence its taste, and potential health benefits [7]. It is not only a re- freshing beverage, but also boasts numerous health benefits, supported by scientific research [8]. Some of the key health benefits associated with regu- lar tea consumption include antioxidant properties, cardiovascular health benefits, weight management, mental health and cognitive function, immune sys- tem support, stress reduction, bone health, skin health, and diabetes management. Polyphenols, such as catechins and flavonoids, help neutralize free radicals and reduce oxidative stress and cel- lular damage [9, 10]. In particular, green tea may help reduce the risk of certain cancers by protect- ing cells from DNA damage and inhibiting tumor growth [11]. Regular tea consumption is associ- ated with improved cardiovascular health [12, 13]. Drinking tea may help lower blood pressure, reduce cholesterol levels, and improve blood vessel func- tion [14]. Some studies have suggested that drink- ing tea may lower the risk of stroke, likely owing to its beneficial effects on blood pressure and choles- terol [15]. The catechin and caffeine components of tea can help boost metabolism and increase fat oxidation, potentially aiding weight loss and man- agement [16]. This can help to regulate appetite and reduce overeating [17]. Caffeine in tea provides a mild stimulant effect, and improves mental alert- ness. Tea, especially green tea, contains L-theanine, which promotes relaxation and can enhance cogni- tive function by working synergistically with caf- feine [18]. Peppermint and ginger tea are known to aid digestion and alleviate symptoms, such as bloating and nausea [19]. Polyphenols in tea can promote the growth of beneficial gut bacteria, con- tributing to a healthy digestive system [20]. Cat- echins in tea have been shown to possess antimi- crobial properties, that can help combat bacteria and viruses [21]. The anti-inflammatory proper- ties of tea can contribute to better joint and bone health [22]. Antioxidants in tea can help protect the skin from damage caused by ultraviolet (UV) rays, thereby reducing the risk of skin cancer and premature aging. Drinking tea may also help im- prove skin hydration and elasticity, giving the skin a healthier appearance [23]. Some studies have sug- gested that green and black tea can help regulate blood sugar levels, improve insulin sensitivity, and reduce the risk of type 2 diabetes [24]. Figure 1: Tea gardens in Nepal. Source: https://highlightstourism.com/2022/12/14/ tea-gardens-a-sight-seeing-in-eastern-nepal. Drinking tea, which is generally considered ben- eficial owing to its antioxidants and other health- promoting compounds, can pose certain health risks. Tea, especially black and green tea, contains caffeine, which can cause sleep disturbances and in- crease anxiety levels in sensitive individuals. Exces- sive and regular consumption of caffeine can lead to heart palpitations and increased heart rate [25,26]. The tannins present in tea leaves hinder the absorp- tion of iron from plant-based diets. Individuals with iron deficiency, pregnant women, and children are at high risk due to tannin contents [27, 28]. Exces- sive tea consumption is associated with decreased bone mineral density and an increased risk of frac- tures, especially in postmenopausal women, owing to the fluoride content of tea leaves [29]. It contains oxalates, which can lead to kidney stones in sen- sitive individuals [30, 31]. Excess tea consumption may lead to health risks due to its high heavy metal content such as Pb, Al, and metal fluorides [32]. Because tea is acidic, some people may experience nausea, acid reflux, or upset stomachs when it is taken on an empty stomach. Tea has been consid- ered as a means of connecting people in society and is a tradition, but not only as a beverage. This study aims to measure and compare the pH values of various Nepalese tea brands under different con- ditions, including brewing times, temperatures, and medium types. 2 Experimental 2.1 Materials and chemicals Four local Nepalese tea brands, Tokla, Ridhisidhi, Suman, and Muna tea, were selected for this study and purchased from the local market of Biratna- gar, Nepal. Distilled water was used to brew the tea samples. They were meshed to remove dirt and brewed according to standard brewing instructions. A digital pH meter was used to measure the pH of brewed tea samples. The pH variation was inves- tigated by varying the brewing conditions, includ- https://highlightstourism.com/2022/12/14/tea-gardens-a-sight-seeing-in-eastern-nepal https://highlightstourism.com/2022/12/14/tea-gardens-a-sight-seeing-in-eastern-nepal Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 323 ing temperature changes and the addition of fresh lemon juice, milk, and sugar to the tea samples. 2.2 Preparation of Tea Samples In each set of experiments, 2 g of dry tea was added to 200 ml of distilled water to prepare tea. The temperature of hot tea was maintained at 90 °C. Various types of tea samples, including teas with milk, sugar, and fresh lemon juice, were prepared using the same procedure but in varying propor- tions. During preparation, the tea samples were occasionally stirred to homogenize them. The pH measurements were performed in triplicate to re- duce error. The entire process of sample prepara- tion and pH measurement is shown in Figure 2. Figure 2: Tea sample preparation and pH measure- ment. 2.3 Statistical Analysis The Origin 2018 version software was used to per- form a one-way ANOVA test to compare the mean differences between multiple groups. The data rep- resents the mean of pH in three replications with ± standard deviation (SD). Pair identification and the display of significant mean differences were ac- complished through post-hoc analysis using Tucky's test. The pH values of p < 0.05 were considered sig- nificant. 3 Results and discussion 3.1 Freshly Brewed Tea The flavor and stability of tea can be greatly influ- enced by pH. Black tea had a pH value of 7.73 to 9.03 under hot conditions, whereas it drops to 7.12 to 7.22 under cold conditions. The pH values of all the freshly brewed teas were within the expected range for black tea, indicating a slightly alkaline na- ture. Suman Tea with a pH of 9.03 under hot condi- tions is relatively more basic than other tea brands. Cooling decreased the pH of all tea brands. As re- ported in previous studies, fresh brewed black tea typically has a pH of 7–9 under hot conditions and a slightly decreased pH of 7.12 7.30 under cold con- ditions [31]. This decrease in pH under cold condi- tions may be due to the release of organic acids [32]. Table 1 presents the pH data for all tea brands un- der cold and hot conditions, which are graphically illustrated in Figure 3. Table 1: pH of black tea in water without flavour S. N. Different Brands of Tea pH Hot Condition Cold Condition 1 Tokla 7.73 ± 0.05 7.2 ± 0.01 2 Ridhisidhi 8.00 ± 0.1 7.18 ± 0.02 3 Suman 9.03 ± 0.05 7.22 ± 0.025 4 Muna 7.76 ± 0.03 7.12 ± 0.005 Each value represents mean pH ± standard deviation (SD) Figure 3: pH of black tea in cold and hot condi- tions. 3.2 Tea with Lemon flavour Table 2 presents the pH data for all brands of black tea containing varying amounts of sugar and lemon juice. The pH value decreased as more sugar was added to the tea. Moreover, an increased concentra- tion of sugar (2 g) resulted in a slightly acidic pH range. Likewise, adding lemon (0.1, 0.2, 0.3, and 0.4 ml), which is highly acidic (pH ~2-3) to black tea containing different levels of sugar (0.5, 1.0, 1.5, and 2.0 g) resulted in a significant drop in pH levels, Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 324 making the tea more acidic. The pH values, ranging from 4.59 to 6.97 after adding lemon to tea, are con- sistent with studies showing that lemon acidity (pH 2-3) lowers the overall pH of tea mixtures [33]. The pH change follows this order: Suman > Ridhisidhi > Muna ~ Tokla. This increase in acidity can en- hance the antioxidant properties of tea, but might also make the tea tangier and sharper in taste. The Tokla tea brand is more acidic in this context, with a pH of 4.59. A study has shown that the addition of lemon can enhance the bioavailability of polyphe- nols, thereby increasing the health benefits of tea. However, increased acidity may pose discomfort is- sues for acid-sensitive individuals [34]. The results of the variation in the pH of sugar-supplemented tea with and without lemon are graphically presented in Figure 4. Table 2: pH of sugar added black tea with and without lemon S. N. Different Brands of Tea Sugar Content pH Lemon contentBlack Tea Black Tea with Lemon 1 Tokla 0.5 gm 7.49 ± 0.005 6.28 ± 0.005 0.1 ml 1.0 gm 7.25 ± 0.01 5.66 ± 0.005 0.2 ml 1.5 gm 7.07 ± 0.005 5.13 ± 0.01 0.3 ml 2.0 gm 6.80 ± 0.01 4.59 ± 0.005 0.4 ml 2 Ridhisidhi 0.5 gm 7.73 ± 0.015 6.97 ± 0.015 0.1 ml 1.0 gm 7.51 ± 0.015 6.39 ± 0.005 0.2 ml 1.5 gm 7.23 ± 0.02 5.86 ± 0.015 0.3 ml 2.0 gm 6.94 ± 0.015 4.77 ± 0.02 0.4 ml 3 Suman 0.5 gm 8.69 ± 0.005 6.67 ± 0.005 0.1 ml 1.0 gm 8.43 ± 0.015 6.08 ± 0.01 0.2 ml 1.5 gm 8.2 ± 0.01 5.55 ± 0.02 0.3 ml 2.0 gm 7.87 ± 0.02 4.97 ± 0.02 0.4 ml 4 Muna 0.5 gm 7.48 ± 0.01 6.35 ± 0.005 0.1 ml 1.0 gm 7.25 ± 0.01 5.83 ± 0.01 0.2 ml 1.5 gm 6.94 ± 0.01 5.27 ± 0.02 0.3 ml 2.0 gm 6.75 ± 0.01 4.75 ± 0.01 0.4 ml Each value represents mean pH ± standard deviation (SD) Figure 4: pH of sugar added black tea with and without lemon. 3.3 Sugar added Tea with Milk Adding milk to tea generally decreases its pH, mak- ing it acidic, which may be due to the buffering ca- pacity of milk that contains proteins and calcium as its main components. The pH of the tea with 100% milk ranged from 6.07 -7.40. Suman Tea had the highest pH value (7.40). This suggests that it might offer the mildest flavor when milk is added. Muna showed the largest decrease in pH (6.07) af- ter the addition of more sugar to 100 % milk tea. When the milk concentration in tea decreases, the pH value increases slightly, moving toward an alka- line nature [35]. However, some studies have raised concerns that milk might decrease the absorption of certain antioxidants in tea, although the extent of this effect remains debated [36]. The variation in the pH profile of milk tea with added sugar is presented in Table 3, and a bar graph showing this effect is shown in Figure 5. Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 325 Table 3: pH of sugar added milk tea with varying milk-water ratios S.N. Different Brands of Tea Sugar Content pH Milk tea without water 75% Milk & 25% Water 50% Milk & 50% Water 1 Tokla 0.5 gm 6.86 ± 0.05 6.91 ± 0.01 6.94 ± 0.005 1.0 gm 6.70 ± 0.01 6.79 ± 0.005 6.86 ± 0.005 1.5 gm 6.56 ± 0.01 6.71 ± 0.005 6.77 ± 0.005 2.0 gm 6.44 ± 0.03 6.54 ± 0.005 6.62 ± 0.02 2 Ridhisidhi 0.5 gm 7.19 ± 0.01 7.16 ± 0.03 7.13 ± 0.06 1.0 gm 6.99 ± 0.005 6.97 ± 0.01 6.98 ± 0.005 1.5 gm 6.78 ± 0.01 6.84 ± 0.01 6.87 ± 0.01 2.0 gm 6.59 ± 0.005 6.69 ± 0.005 6.78 ± 0.005 3 Suman 0.5 gm 7.40 ± 0.01 7.30 ± 0.005 7.21 ± 0.01 1.0 gm 7.24 ± 0.01 7.17 ± 0.005 7.13 ± 0.02 1.5 gm 7.04 ± 0.005 7.03 ± 0.01 7.03 ± 0.01 2.0 gm 6.82 ± 0.01 6.85 ± 0.01 6.91 ± 0.01 4 Muna 0.5 gm 6.65 ± 0.01 6.75 ± 0.02 6.83 ± 0.005 1.0 gm 6.43 ± 0.01 6.58 ± 0.01 6.73 ± 0.02 1.5 gm 6.22 ± 0.01 6.40 ± 0.01 6.62 ± 0.01 2.0 gm 6.07 ± 0.02 6.29 ± 0.01 6.52 ± 0.005 Figure 5: pH of Tea with different % of milk-water ratio and sugar content. 4 Conclusion The pH of four local Nepalese tea brands was successfully investigated and evaluated to compare their acidity and evaluate their health impacts, par- ticularly in acid-sensitive individuals. Most of the teas studied were basic in nature, and pH variation occurred after the addition of ingredients such as milk, sugar, and lemon flavors in different amounts. Plain black tea is mildly alkaline to neutral, which makes it relatively safe for acid-sensitive individ- uals. The lemon-flavored tea is significantly more acidic, which might be due to the acidic components present in lemons. The acidity level of approxi- mately 4.59 can be sufficiently high to induce dis- comfort in individuals with a tendency for acid re- flux or those with sensitive stomachs. Upon adding sugar to milk-based teas, the pH value decreased, even though the teas maintained a more neutral pH across different milk-water ratios. Therefore, acid- sensitive individuals must prefer to drink tea with milk or black tea without lemons to prevent aggra- vating symptoms, as these preparations have a less acidic pH value. Our research findings provide valu- able information about the chemistry of tea and its potential effects on taste and health, especially for consumers who have specific dietary needs or are sensitive to acidity. References [1] H. Brody. Tea. Nature, 566:S1–S1, 2019. [2] S. Samanta. Potential bioactive components and health promotional benefits of tea (camel- lia sinensis). J. Am. Nutr. Assoc., 41:65–93, 2022. https://doi.org/10.1080/07315724. 2020.1827082 [3] E.J. Paul. The story of tea. Roli Books Private Limited, 2005. [4] L.C. Martin. Tea: The drink that changed the world. Tuttle Publishing, 2011. [5] H. Kuang, M. Luo, and X. Fang. History, phi- losophy, and rituals of tea ceremony: Integra- tion of tradition and modernity. J. Tea Sci. Res., 13, 2023. [6] S. Dhakal. Economic analysis of tea farm- ing in jhapa district, nepal. 2023. https: //doi.org/10.26480/fabm.02.2023.71.76 [7] C.S. Murugesh, J.B. Manoj, D.J. Haware, R. Ravi, and R. Subramanian. Influence of wa- ter quality on nutritional and sensory charac- teristics of green tea infusion. J. Food Process Eng., 40:e12532, 2017. https://doi.org/10. 1111/jfpe.12532 [8] M. Luo, R.-Y. Gan, B.-Y. Li, Q.-Q. Mao, A. Shang, X.-Y. Xu, H.-Y. Li, and H.-B. Li. Effects and mechanisms of tea on parkinson’s disease, alzheimer’s disease and depression. Food Rev. Int., 39:278–306, 2023. https:// doi.org/10.1080/87559129.2021.1904413 https://doi.org/10.1080/07315724.2020.1827082 https://doi.org/10.1080/07315724.2020.1827082 https://doi.org/10.26480/fabm.02.2023.71.76 https://doi.org/10.26480/fabm.02.2023.71.76 https://doi.org/10.1111/jfpe.12532 https://doi.org/10.1111/jfpe.12532 https://doi.org/10.1080/87559129.2021.1904413 https://doi.org/10.1080/87559129.2021.1904413 Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 326 [9] Z. Yan, Y. Zhong, Y. Duan, Q. Chen, and F. Li. Antioxidant mechanism of tea polyphe- nols and its impact on health benefits. Anim. Nutr., 6:115–123, 2020. https://doi.org/10. 1016/j.aninu.2020.01.001 [10] A.-R. Zuo, H.-H. Dong, Y.-Y. Yu, Q.-L. Shu, L.-X. Zheng, X.-Y. Yu, and S.-W. Cao. The antityrosinase and antioxidant ac- tivities of flavonoids dominated by the num- ber and location of phenolic hydroxyl groups. Chin. Med., 13:51, 2018. https://doi.org/ 10.1186/s13020-018-0206-9 [11] Y-L Lin, I-M Juan, Y-L Chen, Y-C Liang, and J-K Lin. Composition of polyphenols in fresh tea leaves and associations of their oxygen- radical-absorbing capacity with antiprolifera- tive actions in fibroblast cells. Journal of Agri- cultural and Food Chemistry, 44:1387–1394, 1996. https://doi.org/10.1021/jf950652k [12] U Peters, C Poole, and L Arab. Does tea af- fect cardiovascular disease? a meta-analysis. American Journal of Epidemiology, 154:495– 503, 2001. [13] N Iwai, H Ohshiro, Y Kurozawa, et al. Re- lationship between coffee and green tea con- sumption and all-cause mortality in cohort of a rural japanese population. Journal of Epi- demiology, 12:191–198, 2002. [14] D Li, R Wang, J Huang, et al. Ef- fects and mechanisms of tea regulating blood pressure: Evidences and promises. Nutri- ents, 11(5):1115, 2019. https://doi.org/10. 3390/nu11051115 [15] J Pang, Z Zhang, T Zheng, et al. Green tea consumption and risk of cardiovascu- lar and ischemic related diseases: A meta- analysis. International Journal of Cardiol- ogy, 202:967–974, 2016. https://doi.org/ 10.1016/j.ijcard.2014.12.176 [16] J Mielgo-Ayuso, L Barrenechea, P Alcorta, et al. Effects of dietary supplementation with epigallocatechin-3-gallate on weight loss, en- ergy homeostasis, cardiometabolic risk fac- tors and liver function in obese women: Ran- domised, double-blind, placebo-controlled clin- ical trial. British Journal of Nutrition, 111:1263–1271, 2014. https://doi.org/10. 1017/S0007114513003784 [17] BE Carter and A Drewnowski. Beverages con- taining soluble fiber, caffeine, and green tea catechins suppress hunger and lead to less energy consumption at the next meal. Ap- petite, 59:755–761, 2012. https://doi.org/ 10.1016/j.appet.2012.08.015 [18] C Dietz and M Dekker. Effect of green tea phytochemicals on mood and cog- nition. Current Pharmaceutical Design, 23:2876–2905, 2017. https://doi.org/10. 2174/1381612823666170105151800 [19] C Ravikumar. Review on herbal teas. Jour- nal of Pharmaceutical Sciences and Research, 6:236, 2014. [20] X Wang, Y Liu, Z Wu, et al. Tea polyphenols: A natural antioxidant regulates gut flora to protect the intestinal mucosa and prevent chronic diseases. Antioxidants, 11(2):253, 2022. https://doi.org/10.3390/ antiox11020253 [21] VR Sinija and HN Mishra. Green tea: Health benefits. Journal of Nutritional and Envi- ronmental Medicine, 17:232–242, 2008. https: //doi.org/10.1080/13590840802518785 [22] C Huang and R Tang. Tea drinking habits and osteoporotic hip/femur fractures: A case- control study. Pakistan Journal of Medical Sci- ences, 32:408–412, 2016. https://doi.org/ 10.12669/pjms.322.9092 [23] M.-J. Lee, P. Maliakal, L. Chen, X. Meng, F.Y. Bondoc, S. Prabhu, G. Lambert, S. Mohr, and C.S. Yang. Pharmacokinetics of tea cat- echins after ingestion of green tea and (-)- epigallocatechin-3-gallate by humans: forma- tion of different metabolites and individual variability. Cancer Epidemiology, Biomarkers & Prevention, 11:1025–1032, 2002. [24] J. Yu, P. Song, R. Perry, C. Penfold, and A.R. Cooper. The effectiveness of green tea or green tea extract on insulin resistance and glycemic control in type 2 diabetes mellitus: A meta-analysis. Diabetes & Metabolism Jour- nal, 41:251–262, 2017. https://doi.org/10. 4093/dmj.2017.41.4.251 [25] M.M. Lorist and M. Tops. Caffeine, fatigue, and cognition. Brain and Cognition, 53:82–94, 2003. [26] P. Nawrot, S. Jordan, J. Eastwood, J. Rot- stein, A. Hugenholtz, and M. Feeley. Effects of caffeine on human health. Food Additives & Contaminants, 20:1–30, 2003. https://doi. org/10.1080/0265203021000007840 [27] J. Lee. Association between coffee and green tea consumption and iron deficiency anemia in korea. Korean Journal of Family Medicine, 44:69–70, 2023. https://doi.org/10.4082/ KJFM.44.2E https://doi.org/10.1016/j.aninu.2020.01.001 https://doi.org/10.1016/j.aninu.2020.01.001 https://doi.org/10.1186/s13020-018-0206-9 https://doi.org/10.1186/s13020-018-0206-9 https://doi.org/10.1021/jf950652k https://doi.org/10.3390/nu11051115 https://doi.org/10.3390/nu11051115 https://doi.org/10.1016/j.ijcard.2014.12.176 https://doi.org/10.1016/j.ijcard.2014.12.176 https://doi.org/10.1017/S0007114513003784 https://doi.org/10.1017/S0007114513003784 https://doi.org/10.1016/j.appet.2012.08.015 https://doi.org/10.1016/j.appet.2012.08.015 https://doi.org/10.2174/1381612823666170105151800 https://doi.org/10.2174/1381612823666170105151800 https://doi.org/10.3390/antiox11020253 https://doi.org/10.3390/antiox11020253 https://doi.org/10.1080/13590840802518785 https://doi.org/10.1080/13590840802518785 https://doi.org/10.12669/pjms.322.9092 https://doi.org/10.12669/pjms.322.9092 https://doi.org/10.4093/dmj.2017.41.4.251 https://doi.org/10.4093/dmj.2017.41.4.251 https://doi.org/10.1080/0265203021000007840 https://doi.org/10.1080/0265203021000007840 https://doi.org/10.4082/KJFM.44.2E https://doi.org/10.4082/KJFM.44.2E Narendra Kumar Chaudhary et al./ BIBECHANA 21 (2024) 321-327 327 [28] I.M. Zijp, O. Korver, and L.B.M. Tijburg. Ef- fect of tea and other dietary factors on iron absorption. Critical Reviews in Food Sci- ence and Nutrition, 40:371–398, 2000. https: //doi.org/10.1080/10408690091189194 [29] S.L. Xia, Z.Y. Ma, B. Wang, S.Y. Guo, X.X. Zhou, and F. Gao. The association between tea consumption and the risk of fracture: A dose- response meta-analysis of prospective cohort studies. Journal of Nutrition, Health & Ag- ing, 25:1046–1052, 2021. https://doi.org/ 10.1007/s12603-021-1677-4 [30] R.P. Holmes, H.O. Goodman, and D.G. As- simos. Contribution of dietary oxalate to urinary oxalate excretion. Kidney Interna- tional, 59:270–276, 2001. https://doi.org/ 10.1046/j.1523-1755.2001.00488.x [31] Y.K. Chong and K.L. Nyam. Effect of brewing time and temperature on the physical proper- ties, antioxidant activities and sensory of the kenaf leaves tea. Journal of Food Science and Technology, 59:510–517, 2022. https://doi. org/10.1007/s13197-021-05034-3 [32] E. Damiani, T. Bacchetti, L. Padella, L. Tiano, and P. Carloni. Antioxidant activity of differ- ent white teas: Comparison of hot and cold tea infusions. Journal of Food Composition and Analysis, 33:59–66, 2014. https://doi.org/ 10.1016/J.JFCA.2013.09.010 [33] B. Saletnik, G. Zaguła, D. Grabek-Lejko, I. Kasprzyk, M. Bajcar, M. Czernicka, and C. Puchalski. Effect of infusion time and addi- tion of lemon juice on the mobility of selected macroelements and aluminium during aqueous extraction of quality brands of leaf tea. Jour- nal of Elementology, 23:611–624, 2018. https: //doi.org/10.5601/jelem.2017.22.3.1449 [34] J. Mohammadzadeh Milani, A. Amuzadeh, and A. Moetamedzadegan. Effect of differ- ent additives on antiooxidant capacity of black tea. Journal of Culinary Science & Technology, 18:67–76, 2020. https://doi.org/10.1080/ 15428052.2018.1502114. [35] A. Rashidinejad, E.J. Birch, D. Sun- Waterhouse, and D.W. Everett. Addition of milk to tea infusions: Helpful or harmful? evidence from in vitro and in vivo studies on antioxidant properties. Critical Reviews in Food Science and Nutrition, 57:3188–3196, 2017. https://doi.org/10.1080/10408398. 2015.1099515 [36] M. Serafini, A. Ghiselli, and A. Ferro-Luzzi. In vivo antioxidant effect of green and black tea in man. European Journal of Clinical Nutrition, 50:28–32, 1996. https://doi.org/10.1080/10408690091189194 https://doi.org/10.1080/10408690091189194 https://doi.org/10.1007/s12603-021-1677-4 https://doi.org/10.1007/s12603-021-1677-4 https://doi.org/10.1046/j.1523-1755.2001.00488.x https://doi.org/10.1046/j.1523-1755.2001.00488.x https://doi.org/10.1007/s13197-021-05034-3 https://doi.org/10.1007/s13197-021-05034-3 https://doi.org/10.1016/J.JFCA.2013.09.010 https://doi.org/10.1016/J.JFCA.2013.09.010 https://doi.org/10.5601/jelem.2017.22.3.1449 https://doi.org/10.5601/jelem.2017.22.3.1449 https://doi.org/10.1080/15428052.2018.1502114. https://doi.org/10.1080/15428052.2018.1502114. https://doi.org/10.1080/10408398.2015.1099515 https://doi.org/10.1080/10408398.2015.1099515 Introduction Experimental Materials and chemicals Preparation of Tea Samples Statistical Analysis Results and discussion Freshly Brewed Tea Tea with Lemon flavour Sugar added Tea with Milk Conclusion