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Extract to Fortify the Green Tea Drink Enchanced Antioxidant Activity

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Extract to Fortify the Green Tea Drink Enchanced Antioxidant Activity KKU Res. J. 2015; 20(3) 305 KKU Res.j. 2015; 20(3) : 305-313 http://resjournal.kku.ac.th The Use of Mangosteen Pericarp (Garcinia mangostana L.) Extract to Fortify the Green Tea Drink Enchanced Antioxidant Activity. Rufnia A. Afifah1 and Chutamat Niwat2* 1Department of Food Science and Technology, Faculty of Agricultural Engineering and Technology, Bogor Agricultural University, Bogor, Indonesia 2Food Technology Program, School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand *Correspondenk author : [email protected] Abstract Mangosteen pericarp and tea contain high polyphenol content that has disease preventive properties. This study aimed to utilize mangosteen pericarp for producing added-value product, to evaluate polyphenols stability in green tea drink with mangosteen pericarp extract, and to evaluate the effect of citric acid to the polyphenols stability in green tea drink with mangosteen pericarp extract. Mangosteen pericarp was hot air dried at 50ºC until the moisture content reached 7.43±0.10%. Dried mangosteen pericarp was soaked in distilled water, then the total polyphenol content, DPPH, and FRAP of the extracted solution were analyzed. The extract was added into green tea drink at seven different concentrations (0.1-0.7%). The optimum concentration into green tea was evaluated by sensory test, and then it was mixed with gradual concentrations of citric acid (0.06, 0.1, and 0.2%). The results showed that the total phenolic compound, DPPH and FRAP of the extract were 127.39±1.19 mg GAE/ml sample, 44.92±0.68 mmol TE/ml sample, and 21.49±0.13 mM asorbic acid/ml sample, respectively. The optimum concentration evaluated by sensory test was 0.4%. The mixture of green tea drink with 0.4% mangsteen pericarp extract and 0.2% citric acid showed the lowest pH (2.79), the highest total phenolic compound (25.48±0.38 mg GAE/ml sample), DPPH (57.86±1.25 mmol TE/100 ml sample), and FRAP (5.68±0.33 mM asorbic acid/ml sample) compared with the other treatments (p<0.05). Therefore, mangosteen pericarp extract can be applied in green tea drink and provided more polyphenol content for the product. In addition, citric acid enhanced the stability of polyphenol in green tea drink. Keywords: Antioxidant activity, Citric acid, Green tea, Mangosteen pericarp, Polyphenol. 306 KKU Res. J. 2015; 20(3) 1. Introduction mangosteen pericarp extract may add bitter taste to the green tea drink and yet may Garcinia mangostana L. or mangosteen increase functional properties like antioxidant is a tropical fruit from the family Guttiferae activity because of its high polyphenol (1). Thailand and Indonesia are one of the content. Additionally, the tea condition may high mangosteen production countries, affect the stability of the polyphenol in both where the production is approximately three mangosteen pericarp extract and green tea. and two million tons, respectively (2). The objectives of this research were to Mangosteen consists of endocarp and utilize mangosteen pericarp for producing pericarp. Mangosteen pericarp is the largest added-value product, to evaluate polyphenols part of the fruit, which comprises 66.67% stability in green tea drink with mangosteen of the total fruit (3). The pericarp is usually pericarp extract, and to evaluate the effect discarded as waste due to its unpleasant of citric acid to the polyphenols stability in taste of bitterness, however, it can be a good green tea drink with mangosteen pericarp source of antioxidant according to its rich extract. polyphenol content, such as xanthone (4). The mangosteen pericarp also contains 2. Material and methods tannin that may interfere protein absorption in digestive system when it is consumed in Mangosteens and dried green teas high content (5). Thus, the consumption of were purchased from Baan Duu Market, mangosteen pericarp has increased as Chiang Rai, Thailand. Sucrose and fructose dietary supplement due to their potential syrup (Mitr Phol®, Thailand) were also pharmacological properties (4). The purchased from a local market. extraction of mangosteen pericarp can also Folin-Ciocalteu’s phenol reagent and contain high polyphenol content, therefore trichloroacetic acid from LobaChemi®, it can easily be mixed into food products India; gallic acid, 2,2-Diphenyl-1-picrylhy- and/or beverage like tea. drazyl, and Trolox-6-hydroxy-2,5,7, Tea is one of the most popular drinks 8-tetramethyl-chroman-2-carboxylic acid in the world. More than three billion cups and potassium hexacyano-ferrate (III), from of tea are consumed per day (6). Recently, Sigma Aldrich®, Canada; sodium carbonate, popularity of tea has increased due to its ascorbic acid and sodium dihydrogen potential health benefits against cardiovascular phosphate from Ajax Finechem®, New diseases and cancer from its antioxidant Zealand; iron (III) chloride hexahydrate and activities (7). Mangosteen pericarp extract disodium hydrogen phosphate from and green tea drink are matched due to the Fisher®, UK were used as chemical regents. acidity properties. The phytochemical 2.1 Preparation of Extract from screening performed on the mangosteen Mangosteen Pericarp pericarp extract showed that the extract is Extraction methods were modified acidic with pH 5 (8). In tea drink, polyphenols from Cheok et al. (10) and Zarena and are stable when pH is below 4 and they are Sangkar (11). Mangosteen was washed and unstable in solutions with pH above 6 (9). separated between fruit and pericarp, and Commercially, the pH of tea drinks is usually then weighed. Mangosteen pericarp was hot adjusted to pH 3.8-4.0. Addition of air dried at 50°C until the moisture content KKU Res. J. 2015; 20(3) 307 reached 7%, then ground into powder using were analyzed for total polyphenols content, a hammer mill (Baan Pramong Co. Ltd, DPPH, and FRAP. Thailand). 2.2 Tea Drink Fortified with Mangosteen pericarp powder (20 g) Mangosteen Pericarp Extract was accurately weighed and placed in a 250 Dried green tea leaves (2 g) were ml Erlenmeyer flask, then distilled water brewed with 150 ml boiled water (95°C) for (100 ml) was added. The mixture was 2 min and filtered. Green tea infusion was stirred for 20 hours on a shaking water bath mixed with 8% fructose and 3% sucrose at 25°C, then centrifuged at 5,000 rpm for (w/v). Varying concentrations of extract 10 min and filtered using Whatman filter (0-0.7%) were then added to the green tea paper No. 1. The filtrate was concentrated drink as shown in Table 1. The optimum using a rotary evaporator controlled at 40°C concentration of mangosteen pericarp for 1 hour at 120 rpm, and then the volume extract applied in green tea drink was of each extract was collected. The extracts obtained from sensory test. were stored in refrigerator 4°C until they Table 1. Formulation of tea drink fortified with mangosteen pericarp extract. Control T1 T2 T3 T4 T5 T6 T7 Ingredients Concentration (%) Tea infusion 88.7 88.7 88.7 88.7 88.7 88.7 88.7 88.7 Fructose 8 8 8 8 8 8 8 8 Sucrose 3 3 3 3 3 3 3 3 Extract 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Next, gradual concentrations of citric mixture stirred until homogenized. Tea acid (0.06, 0.1, and 0.2% w/v) were added drink was then pasteurized at 70oC for 2 min to green tea drink (Table 2). Mangosteen and hot-filled in pasteurized bottles and pericarp extract was then added and the cooled to 40°C (12). Table 2. Formulation of tea drink fortified with mangosteen pericarp extract and citric acid. Control T4 TC1 TC2 TC3 Ingredients Concentration (%) Tea infusion 88.7 88.7 88.7 88.7 88.7 Fructose 8 8 8 8 8 Sucrose 3 3 3 3 3 Extract 0 0.4 0.4 0.4 0.4 Citric acid 0 0 0.06 0.1 0.2 308 KKU Res. J. 2015; 20(3) 2.3 pH measurement 2.7 Ferric Reducing Antioxidant pH of green tea drinks with mangosteen Power (FRAP) pericarp extract were measured according Ferric reducing antioxidant power to AOAC using a pH meter (13). was assayed by Benzie and Strain with few 2.4 Moisture content of modification using ascorbic acid as Moisture content of the dried pericarp standard (17). Mangosteen pericarp extract powder was determined using an oven was diluted 1:200 and tea drink was diluted dryer for overnight or to constant the weight with ratio 1:100, both with distilled water. (14). Diluted mangosteen pericarp extract and 2.5 Total polyphenol content green tea drinks (1.0 ml) were mixed with Total polyphenol content was assayed 2.5 ml 0.2 M phosphate buffer (pH 6.6) and according ISO 14502-1 using gallic acid as 2.5 ml 1% potassium hexacyanoferrate (III). a standard (15). Mangosteen pericarp The mixture was incubated at 50ºC for 30 extract was diluted 1:200 and tea drink was min, then 2.5 ml of 10% trichloroacetic acid diluted with ratio 1:100, both with distilled was added and the mixtures centrifuged for water. Diluted mangosteen pericarp extract 10 min. Supernatant (2.5 ml) was mixed and green tea drinks (1.0 ml) were put into with 2.5 ml of water and 0.5 ml of 1% ferric a tube. Then, 5.0 ml of 10% v/v Folin- chloride. Then, absorbance was measured Ciocalteu reagent and 4.0 ml of 7.5% w/v at 700 nm. sodium carbonate solution was added with 2.8 Sensory Evaluation mixing. The mixture was left for 1 hour at Sensory qualities of green tea drink room temperature and the absorbance with mangosteen pericarp extract were measured at 765 nm using water as blank.
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