Co-pigmentation of purple sweet potatos (ipomoea batatas l) anthocyanin extract using green tea extract

Journal of Physics: Conference Series PAPER • OPEN ACCESS Co-pigmentation of purple sweet potatos (ipomoea batatas l) anthocyanin extract using green tea extract To cite this article: R Yunilawati et al 2019 J. Phys.: Conf. Ser. 1317 012105 View the article online for updates and enhancements. This content was downloaded from IP address 192.210.185.17 on 10/11/2019 at 12:19 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 Co-pigmentation of purple sweet potatos (ipomoea batatas l) anthocyanin extract using green tea extract R Yunilawati1*, Yemirta1, AA Cahyaningtyas1 and A H Saputro2 1) 2) Badan Penelitian dan Pengembangan Industri - Kementerian Perindustrian Department of Physics, University of Indonesia * retnoyunilawati@gmail.com Abstract. Copigmentation is one of the methods to stabilize and enhance the anthocyanin.color. Green tea has the phenolic compounds (one of them is catechin) that potentially serves as co-pigment. In this study co-pigmentation of purple sweet potato (Ipomoea batatas L) anthocyanin extract with green tea extract were investigated. The anthocyanin was extracted with water at pH 2. Green tea extract was made by maceration in hot water by varying time. The co-pigmentation was conducted by varying ratio of anthocyanin.extract with green tea extract (1:1; 1: 2; 1: 3; 1: 4; and 1:5). The results showed that the total anthocyanin in anthocyanin extract from purple sweet potato was 1700 ppm, the total polyphenol in green tea extract was 10014 ppm. Green tea extract can be used as copigment for anthocyanin from purple sweet potato by evaluating the bathochromic effect (maximum wavelength shift, Δλmax) and hyperchromic effect (the increase of absorbance, ΔAmax). Green tea extract showed the best co-pigmentation in the ratio (1: 1) while the bathochromic effect (Δλmax) was 4 nm and hyperchromic effect (ΔAmax) was 0.548. 1. Introduction The use of natural color in foods and beverages has increased as substitutes for their synthetic colorants. This is caused the increasing awareness of the environmental hazards and the potential sideeffect impacts of synthetic food coloring [1]. Food colorants from plant tissue are widely developed, especially from some edible sources, one of them are anthocyanins. Anthocyanins pigments are watersoluble, widely distributed in the plant. The molecules of anthocyanin are flavonoids group, play a role for the color of red, purple, and blue. Fruits and vegetables were source of anthocyanin extracts can be used as food colorants to sustitute the synthetic color. Anthocyanins also showed some biological functions, like antioxidant, anti-carcinogen activities, anti-inflammatory, hepato-protection capacity and the ability to enhance memory [2][3]. Anthocyanins can also increase the processed foods nutritional value by preventing lipids and proteins oxidation in the food products [4]. Therefore, increasing the application use of anthocyanin in food and beverages industry is very important because of their potential health benefits besides attractive colors. Anthocyanins, like most natural pigments, are unstable and susceptible to degradation easily. The stability of anthocyanin color is affected by pH, solvents, temperature, concentration, structures of anthocyanins, oxygen, light, enzymes, and other substances attached to them. The anthocyanin color stability can be improved by co-pigmentation. Copigmentation is a phenomenon where natural dyes and colorless organic compounds or metal ions form molecular or complex associations. In coContent from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 pigmentation, the anthocyanin molecule reacts with co-pigment directly or through weak interactions, producing an enhanced and stabilized color. Copigments are colorless, but when added to the anthocyanin solution, they increase the color intensity and the stability of the solution. Copigment compounds generally are flavonoids, polyphenols, alkaloids, organic acids, and amino acids. Flavonoids are well-known co-pigments among which flavons, flavonols, flavonons, and flavanols have been vastly studied. Polyphenols are compounds that are naturally found in plants, contain many phenol groups that can function as antioxidants and are one type of co-pigment that can be used to improve the stability of natural dyes. Green tea has the rich phenolic compound that potentially serves as co-pigment. The major constituents in tea polyphenols are catechins with flavan3ols structures and their polymerized products. The polyphenols content in green tea can reach up to 30% by weight [5]. The high content of polyphenols in green tea allows it to become a co-pigment for anthocyanins. The current study aims to co-pigmentation anthocyanin extract of purple sweet potato with the green tea extract. Copigmentation phenomena are observed as a bathochromic shift (maximum wavelength shift,) and hyperchromic effect (the increase of absorbance). 2. Materials and Methods 2.1. Materials The materials for this research are the purple sweet potato obtained from Bogor, green tea and citric acid (food grade) from local market, folin ciocalteu reagent, sodium carbonate (20%), and gallic acid from Merck. 2.2. Methods 2.2.1. Anthocyanin extraction. The anthocyanin extraction was done based on previous work [6]. The washed and dried purple sweet potato are cut into small pieces, blanched at 70 ° C by adding water 1:2 (w/v)for 10 minutes, and then filtered. The filtrate was added citric acid until pH 2, then mix with the pulp and blended briefly, heated in 90 C for 10 minutes, and then filtered. The filtrate is centrifuged to precipitate the carbohydrate and concentrated using a rotary evaporator to obtained filtrate volume a half of initial volume. The total anthocyanin content was evaluated using the pHdifferential method. 2.2.2. Green tea extraction. Extraction of green tea was done by maceration using water (1:2 w/v) at 80 ° C with varying of time (5 minutes, 10 minutes, 15 minutes, and 20 minutes). The extract is then filtered using carbon active and determined the total polyphenols using Folin Ciocalteu method [7]. A sample of diluted extract (20 µL) was added to distilled water (1.58 mL) in a test tube. After the addition of of Folin-Ciocalteu reagent (100 μL) and saturated Na2CO3 20 % (300 μL), the solution was incubated at 40°C for 30 min. The absorbance of the samples was then measured at 765 nm. Total phenols of green tea extract were expressed as mg gallic acid (GAE). Green tea extract with the highest levels of polyphenols from the maceration process that will be used for purple sweet potato anthocyanin co-pigmentation. 2.3. Co-pigmentation. Co-pigmentation was carried out by mixing purple sweet potato anthocyanin and green tea extract in varying volume ratio 1: 1; 1; 2; 1: 3; 1: 4; and 1: 5. Absorption spectra of purple sweet potato anthocyanin solutions, with and without green tea extract were recorded using a UV-visible spectrophotometer, scanning the visible range from 450 nm to 600 nm. The maximum absorbance change (Amax) at varying wavelengths (λmax) presented the difference in the color intensity, and revealed the possibility of hyperchromic effect (ΔAmax) and bathochromic shift (Δλ), resulting from a co-pigmentation reaction. Optimal co-pigmentation products are stored at room temperature and the absorbance is measured daily and compared to antocyanins without co-pigment. 2 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 3. Results and Discussions Polyphenols are chemical compounds with the basic structure of phenols, naturally present in plants and are useful as antioxidants. Polyphenol extraction from green tea was carried out by maceration using water as solvent at 80 ° C in different times. The total polyphenol content (calculated as gallic acid) of each extract is shown in Figure 1. The highest total polyphenol content was obtained in maceration for 10 minutes with the total polyphenol was 10014.93 ppm (mg/L). Maceration with more than 10 minutes produced the darker extract and the lower total polyphenol. Prolonged heating caused the oxidation of polyphenols [8] so the total polyphenol was decreased after maceration for 10 minutes. The darker extract was also avoided because for applications as co-pigments can interfere with the intensity of color. The extract of green tea polyphenols which was carried out from maceration for 10 minutes be used as a co-pigment in this study. Time of maceration (minutes) 25 20 15 10 5 0 0 2000 4000 6000 8000 10000 Polyphenols (mg/L) Figure 1. The polyphenol total of green tea extract in varying time of maceration Anthocyanins are the most abundant flavonoid constituent of red fruits and vegetables and are used as natural color which soluble in water [9]. These pigments are responsible for the red colors, blue, or purple. The use of anthocyanin in food and beverages have many benefits, besides their attractive colors, they have any function for healthy, like antioxidant, anticancer, and anti-inflammatory. The extraction of anthocyanin in purple sweet potatoes was carried out using water solvents by blanching method. Blanching is one of the most critical steps to increase the stability of purple sweet potato anthocyanins. Blanching can reduce the activity of peroxidase enzyme which makes the anthocyanin color become brownish. Analysis using an UV-vis spectrophotometer shows the optimum absorbance at wavelength 530 nm (Figure2) as in some previous research [10][11]. The concentrated anthocyanin extract contains a total anthocyanin level of 1700 mg / L (calculated as cyanidin glucoside) 3 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 1.4 Absorbance 1.2 1.0 0.8 0.6 0.4 0.2 460 480 500 520 540 560 580 600 620 Wavelength (nm) Figure 2. Visible spectra of purple sweet potato anthocyanin extract Anthocyanins have unstable properties and susceptible to degradation easily. The anthocyanins color stability can be improved by co-pigmentation. In co-pigmentation, an unstable dye molecule reacts with other natural components of the plant directly or through the interaction of covalent bond formation to produce a more stable color [11]. The covalent bond in anthocyanin molecules can occur with an organic acid, an aromatic acyl group, or a flavonoid [12]. Purple sweet potato anthocyanin copigmentation was carried out by adding green tea extract which was rich in polyphenol compounds. The co-pigmentation was conducted by varying ratio of anthocyanin.extract with green tea extract extract (1:1; 1: 2; 1: 3; 1: 4; and 1:5). Co-pigmentation of purple sweet potato anthocyanin has been done previously using organic acids (ferrulic acid and tannic acids) [13]. The result of the addition of green tea extract co-pigments at five concentration levels showed that the outcome of co-pigmentation is dependent on co-pigment concentration. Characteristics of copigmentation can be observed using the UV-vis spectrum to evaluate the presence of hyperchromic effects (increase in intensity/ΔA) or bathochromic shift (shift in wavelength toward visible light/Δλmax) [14]. Absorption spectra of anthocyanin and the co-pigmentation are shown in Figure 2. 2.0 1.8 1:1 1:3 1:2 1:4 1:5 Anthocyanin Absorbance 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 460 480 500 520 540 560 580 600 620 Wavelenght (nm) Figure 3. The absorbtion spectra of anthocyanin (without and with copigment) 4 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 The phenomenon of bathochromic shift (Δλmax) and hyperchromic shift (ΔA) in each variation of copigmentation are shown in Table 1. Increasing green tea extract concentration decreases the absorbance of the outcome of co-pigmentation. The effect of bathochromic occurs in all copigmentation process with Δλmax is 4 nm. The effect of hyperchromic happens on co-pigmentation with ratio co-pigmentation are 1:1, 1:2, and 1:3. The co-pigmentation with ratio 1:1 give the greatest hyperchromic effect (0.548), so the best condition on co-pigmentation is in ratio 1:1.Co-pigmentation of purple sweet potato with green tea extract produces highly pigmented new anthocyanin-catechin complexes linked by CH3CH bridges [15]. These complexes linked results more stable color in anthocyanin. Table.1. Optimation of copigmentation purple sweet potato anthocyanin using green tea extract Anthocyanin : green tea extract λmax Δλmax Absorbans ΔA (volume) (nm) (A) 1. Anthocyanin 530 0.872 2. 1:1 534 4 1.420 0.548 3. 1:2 534 4 0.952 0.080 4. 1:3 534 4 0.898 0.026 5. 1:4 534 4 0.695 -0.177 6. 1:5 534 4 0.630 -0.242 Figure 4 showed the changes in absorbance of purple sweet potato anthocyanin and purple sweet potato anthocyanins with co-pigment (green tea extract) are stored at room temperature. Anthocyanin was easily degraded during storage, causing anthocyanin color fading, which were indicated by the decreasing of absorbance. The absorbance decreasing of anthocyanins by the co-pigmentation with green tea extract was slower than anthocyanin without green tea extract. The co-pigmentation of green tea extract can prevent anthocyanin degradation during storage in room temperature. No. 1.4 1.2 Absorbance 1.0 0.8 Without co-pigment With co-pigment 0.6 0.4 0.2 0.0 0 2 4 6 8 10 Days Figure 4. Influence of time storage in room temperature on absorbance of anthocyanin with and without co-pigment (green tea extract) 4. Conclusion Green tea extract showed the best co-pigmentation in ratio purple sweet potato anthocyanin and green tea extract (1: 1) while the bathochromic effect (Δλmax) was 4 nm and hyperchromic effect (ΔAmax) 5 ICOMSET2018 IOP Conf. Series: Journal of Physics: Conf. Series 1317 (2019) 012105 IOP Publishing doi:10.1088/1742-6596/1317/1/012105 was 0.548. The co-pigmentation of green tea extract can prevent anthocyanin degradation during storage in room temperature. References [1] Carocho M, Barreiro MF, Morales P, Ferreira ICFR. 2014. Adding molecules to food, pros and cons: A review on synthetic and natural food additives. Compr Rev Food Sci Food Saf 13:377–99 [2] Cho, J., Kang, J. S., Long, P. H., Jing, J., Back, Y., & Chung, K. S. 2003. Antioxidant and memory enhancing effects of purple sweet potato anthocyanin and cordyceps mushroom extract. Archives of pharmacal research, 26(10), 821-825 [3] Hwang, Y. P., Choi, J. H., Choi, J. M., Chung, Y. C., & Jeong, H. G. 2011. Protective mechanisms of anthocyanins from purple sweet potato against tert-butyl hydroperoxideinduced hepatotoxicity. Food and chemical toxicology, 49(9), 2081-2089 [4] Viljanen, K., Kivikari, R., & Heinonen, M. 2004. Protein− lipid interactions during liposome oxidation with added anthocyanin and other phenolic compounds. Journal of Agricultural and Food Chemistry, 52(5), 1104-1111. [5] Chacko, S. M., Thambi, P. T., Kuttan, R., & Nishigaki, I. 2010. Beneficial effects of green tea: a literature review. Chinese medicine, 5(1), 13 [6] Yunilawati, R., Yemirta, Y., Cahyaningtyas, A. A., Aviandharie, S. A., Hidayati, N., & Rahmi, D. (2018). Optimasi Proses Spray Drying Pada Enkapsulasi Antosianin Ubi Ungu. Jurnal Kimia dan Kemasan, 40(1), 17-24 [7] Singleton, V. L., Orthofer, R., & Lamuela-Raventós, R. M. 1999. Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent. In Methods in enzymology (Vol. 299, pp. 152-178). Academic press. [8] Li, N., Taylor, L. S., Ferruzzi, M. G., & Mauer, L. J. (2013). Color and chemical stability of tea polyphenol (−)-epigallocatechin-3-gallate in solution and solid states. Food research international, 53(2), 909-921 [9] Montilla, E. C., Hillebrand, S., & Winterhalter, P. 2011. Anthocyanins in purple sweet potato (Ipomoea batatas L.) varieties. Fruit, Vegetable and Cereal Science and Biotechnology, 5(2), 19-23 [10] He, Xiu-li, Xue-li Li, Yuan-ping Lv, dan Qiang He. 2015. “Composition and color stability of anthocyanin-based extract from purple sweet potato.” Food Science and Technology 35 (3): 468–73. doi:10.1590/1678-457X.6687. [11] Ghasemifar, E., S. Saeidian, and P. Setareh. 2013. “Stability of Seedless Red Grape Anthocyanin under the Effect of Chlorogenic Acid Copigment, Heating and UV Irradiation.” Journal of Novel Applied Sciences 2 (11): 594–97. [12] Eiro, M. J., & Heinonen, M. (2002). Anthocyanin color behavior and stability during storage: effect of intermolecular copigmentation. Journal of Agricultural and Food Chemistry, 50(25), 7461–6. [13] Susanti, I., Wijaya, H., Hasanah, F., & Heryani, S. 2018. Copigmentation Of Anthocyanin Extract of Purple Sweet Potatoes (Ipomea Batatas L.) Using Ferulic Acid And Tannic Acid. In IOP Conference Series: Earth and Environmental Science (Vol. 116, No. 1, p. 012006). IOP Publishing. [14] Trouillas, P., J. C. Sancho-García, V. De Freitas, J. Gierschner, M. Otyepka, and O. Dangles. 2016. “Stabilizing and Modulating Color by Copigmentation: Insights from Theory and Experiment.” Chemical Reviews 116 (9): 4937–82. doi:10.1021/acs.chemrev.5b00507 [15] Timberlake, C. F., & Bridle, P. (1977). Anthocyanins: colour augmentation with catechin and acetaldehyde. Journal of the Science of Food and Agriculture, 28(6), 539–44. 6