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Antioxidant Activity of Archidendron pauciflorum, Syzygium oleana, Mangifera indica, Theobroma cacao and Cinnamomum burmannii Young Leaves and Their Application as Jelly Drink Colourants



Tuty Anggraini, Vio Novendra and Novelina
 
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ABSTRACT

Background and Objectives: Natural dyes have been used in the food industry and pigments from plants are widely used as such dyes. This research aimed to determine the characteristics of natural dye extracts from the young leaves of Archidendron pauciflorum (A. pauciflorum), Syzygium oleana (S. oleana), Mangifera indica (M. indica), Theobroma cacao (T. cacao) and Cinnamomum burmannii (C. burmannii) and to examine their application as a colourant in jelly drinks. Materials and Methods: The young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii were exposed to Folin-Ciocalteu reagents and Diphenyl Pycryl Hydrazyl (DPPH). The method used in this research was exploratory, 5 treatments were performed on young A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii leaf extracts before their subsequent application in a jelly drink. The pH and antioxidant activity were measured, as were the total polyphenol and anthocyanin contents of young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii and their subsequent application in jelly drinks. Results: The results showed that the antioxidant activity and total polyphenol content of A. pauciflorum both in extract and jelly drinks were the highest among the young leaves. Values of the anthocyanin content in young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii were 17.90±0.03, 19.34±0.02, 74.39±0.07, 26.84±0.01 and 21.61±0.02 mg L–1, respectively, while the anthocyanin contents of jelly drinks made with A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii jelly drinks were 6.90±0.02, 7.39±0.03, 11.79±0.04, 11.79±0.04 and 2.69±0.02 mg L–1, respectively. Conclusion:The young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii can potentially be used as colourants in jelly drinks.

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Tuty Anggraini, Vio Novendra and Novelina , 2018. Antioxidant Activity of Archidendron pauciflorum, Syzygium oleana, Mangifera indica, Theobroma cacao and Cinnamomum burmannii Young Leaves and Their Application as Jelly Drink Colourants. Pakistan Journal of Nutrition, 17: 492-499.

DOI: 10.3923/pjn.2018.492.499

URL: https://scialert.net/abstract/?doi=pjn.2018.492.499
 
Received: November 15, 2017; Accepted: July 10, 2018; Published: September 15, 2018


Copyright: © 2018. This is an open access article distributed under the terms of the creative commons attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.

INTRODUCTION

Jelly drinks are popular food products for all age groups as sources of carbohydrates, such as sugars, fibres and other components. Jelly drinks can be categorized as functional foods because of their health benefits. Jelly drinks usually have attractive colours that make the drink more desirable to consumers. Thus, the best dyes for food products are natural dyes. In addition to their function of making products more attractive, natural dyes are a source of biocompatible components that function as antioxidants. For example, anthocyanins in raspberry and blackberry have been shown to have the potential to inhibit cancer growth, particularly in colon and breast cancer1,2.

Natural dyes such as anthocyanins, carotenoids, chlorophyll and betacyanin are derived from plants or animals. Natural dyes have been used in the food industry, but as technology develops, the use of synthetic dyes is also growing. Synthetic dyes are easier to obtain cheaply and many food manufacturers use these synthetic dyes to reduce production costs. However, the use of synthetic dyes is bad for human health3,4.

According to Hii et al.5 Theobroma cocoa contains bioactive compounds in the form of phenolic compounds, which have antioxidant properties. Theobroma cocoa leaves contain theobromine, caffeine, anthocyanin, leucoanthocyanidin and catechol at levels that vary by the age of the leaves and age of the plant. According to Ramirez et al.6, gallic acid, quercetin, 3-D glucoside, tocopherol, 3-methyl-gallate, propyl gallate, propyl benzoate, catechin, epicatechin, benzoic acid and D-glucose are compounds present in M. indica leaves. In Indonesia, plants, such as Archidendron pauciflorum (A. pauciflorum), Syzygium oleana (S. oleana), Mangifera indica (M. indica), Theobroma cacao (T. cacao) and Cinnamomum burmannii (C. burmannii) are widely found and their fruits and other plant parts are usually consumed. Young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii plants can be potentially used as dyes because of their red colour. However, people have not used these young leaves as a colouring material. If viewed in terms of the young leaf colour, these plants can be used as a material for natural dyes that allegedly have an anthocyanin component. There is a lack of information about the use of the pigments of these young leaves, which has increased research interest in this topic.

Syzygium oleana plants are of concern due to the presence of phenol in their red shoots. According to Anggrani7, the fruits and leaves of S. oleana contain antioxidants, such as total polyphenols and anthocyanins and can be applied to food products. The application of colourants in food products, such as jelly drink products, is very important. Jelly drinks are made of a gel-shaped liquid product that is easily aspirated, is chewy and can be consumed to delay hunger. Gels can be formed through formation of the junction zone by hydrocolloids (such as carrageenan) along with sugars and acids. Before their application in jelly drinks, the antioxidant activity of the young leaves is measured at various incubation times. Therefore, the purpose of this study was to evaluate the antioxidant activity, total polyphenols and anthocyanin content in A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii young leaf extracts as well as their use in making jelly drinks.

MATERIALS AND METHODS

Materials: The materials used in this study are the young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii, sugar, water, seaweed and lime. Additionally, for chemical analysis, materials such as HCl, methanol, ethanol, Folin-Ciocalteu reagent and DPPH and the microbiological analysis used plate count agar (PCA) media.

Methods: This study used an exploratory method and the treatment involved the addition of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii young leaves into jelly drinks.

Creating the young leaf extracts: Young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii were sorted and then weighed and up to 300 g was then crushed and added to 150 mL of water and filtered. After filtration of the extract, it was evaporated with a rotary vacuum evaporator for 1 h.

Creation of the jelly drink: As much as 10 g of seaweed was then added to 200 mL of water and heated for 1 h at 100°C. After this mixture was filtered, 50 mL of seaweed and filtered water was added to a mixture of 0.5 mL of lime juice, 15% sugar and 10% young leaf extract.

Observations: The pH and antioxidant activity as well as total polyphenol and anthocyanin levels and colour (Hunter Lab) were measured for each of the jelly drinks containing the young leaf extracts (A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii).

Antioxidant activity: Antioxidant activity was determined using the method originally developed by Blois8. A portion (0.1 mL) of the extracted solution (1.0 mg mL–1 methanol) for each young leaf of T. cocoa, M. indica, A. pauciflorum, S. oleana and C. burmannii extract and each jelly drink product were placed in a test tube and well mixed with 3.9 mL of methanol and 1.0 mL of a DPPH solution (1.0 mM in methanol). The mixture was stored at an ambient temperature for various incubation times (2, 15, 30, 45 and 60 min) prior to absorbance measurements at 517 nm (A517 nm). For the jelly drink product measurement, the incubation time was dependent on the results obtained for the optimal incubation time for the extract. All measurements were performed in triplicate.

Total polyphenol test9: The stages of testing the total polyphenol content are as follows:

One gram of the sample was weighed, placed in 10 mL of methanol and put into the vortex for 15 min
Extract was brought up to 1 mL in volume
Two millilitres of distilled water and 1 mL of Folin-Ciocalteu reagent were added
Sample was vortexed for 5 min
One millilitre of 5% Na2CO3 was added
Reaction was allowed to proceed for 60 min in the dark
Absorbance was measured at a wavelength of 725 nm

Anthocyanin content10: For analysis of the anthocyanin content, 1.86 g of KCl was placed in a beaker and distilled water was added to a final volume of approximately 980 mL. The pH was measured and adjusted to a pH of 1.0 (±0.05) with HCl (approximately 6.3 mL). Then, 1 L was transferred to a volumetric flask and diluted to a certain volume (1 L) with distilled water.

pH 4.5 buffer (sodium acetate, 0.4 M): Next, 54.43 g of CH3CO2Na•3H2O was weighed in a beaker and distilled water was added to a final volume of approximately 960 mL. The pH was measured and adjusted to a pH of 4.5 (±0.05) with HCl (approximately 20 mL) and the solution was transferred to a 1 L volumetric flask and diluted with distilled water. The anthocyanin pigment concentration was then calculated and expressed as cyanidin-3-glucoside equivalents, as follows10:


Where:
A = (A520-A 700 nm) pH 1.0-(A520-A700 nm) pH 4.5
MW (molecular weight) = 449.2 g mol–1 for cyanidin-3-glucoside (cyd-3-glu)
DF = Dilution factor established in d
l = Pathlength in cm,= 26 900 molar extinction coefficient (ε), in L and mol–1 and cm–1, for cyd-3-glu
103 = Factor for conversion from g to mg

RESULTS AND DISCUSSION

Analysis of the raw materials
Degree of acidity (pH): The pH of a material is measured to determine its acidity. Based on the analysis performed in this study, the pH values are presented in Table 1.

Table 1. Average Results of an Analysis of the Degrees of Acidity of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii Young Leaves.

Based on Table 1, the degree of acidity (pH) of the raw material ranged from 3.72-5.37. The level of acidity could influence the taste of the jelly drink. In addition to the taste, the acidity will affect the anthocyanin or other polyphenol stability. Diglycoside derivatives are more stable in neutral pH conditions, contrary to the aglycons11. Based on Table 1, S. oleana has the most acidic compounds, followed by C. burmanii, M. indica, A. pauciflorum and T. cacao. There is very little information available on the organic acid compounds of these plants, since the uses for the leaves of these plants are still unknown.

Antioxidant activity measured with DPPH: Antioxidant activity is a widely used term for a parameter that characterizes the ability of different substances and food samples to capture or neutralize free radicals.

Table 2 shows that A. pauciflorum has the fastest reaction time with DPPH, while M. indica and T. cacao need 30 min to react optimally with DPPH. Cinnamomum burmannii needs 45 min of incubation time and S. oleana needs 60 min of incubation time.

Table 1:
Average results of an analysis of the degrees of acidity of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii young leaves

Table 2:
Antioxidant Activities of A. pauciflora, S. oleana, M. indica, T. cacao and C. burmannii young leaves at various incubation times

Table 3:
Total polyphenol analysis of the young leaves of A. pauciflora, S. oleana, M. indica, T. cacao and C. burmannii

Table 4: Anthocyanin content in the young leaves of A. pauciflora, S. oleana, M. indica, T. cacao and C. burmannii

A. pauciflorum has the highest antioxidant activity, followed by S. oleana, T. cacao and M. indica and the young leaves of C. burmannii had the lowest antioxidant activity. To measure the antioxidant activity in A. pauciflorum, 2 min was the optimal time. Therefore, based on the antioxidant properties in A. pauciflorum, the leaves can be classified as a fast-acting material that interacts with DPPH in a short time.

According to Anggraini7, the optimal time to incubate DPPH with samples of S. oleana fruit is for 30 min. Some antioxidants react with DPPH in a short time, but other antioxidants are more reactive with DPPH. It is very important to identify the optimal time for incubation because each plant has a different type of antioxidant with different mechanisms of reaction with DPPH. The important role of anthocyanin in antioxidant activity depends on its pH as well as the proportion of protonated, deprotonated, hydrated and isomeric forms. The antioxidant activities of anthocyanin forms at a pH of 7 decrease in the following order: Cyanidin-3-rutinoside>malvidin-3-monoglucoside = delphinidin-3-mono-glucoside>petunidin-3-monoglucoside12. The leaves of A. pauciflorum are effective against hepatitis C virus and the chronic liver diseases it causes13.

Total polyphenol analysis: The results of the total polyphenol analysis obtained from the raw materials of each young leaf are presented in Table 3.

Table 3 shows that the total polyphenol content ranged from 518-1328 mg GAE/g. A. pauciflorum has the highest total polyphenol content, while cinnamon has the lowest. The total polyphenol content has a positive correlation with antioxidant activity. Polyphenol compounds have an aromatic ring containing one or more hydroxy groups. The antioxidant activity of the phenolic compounds is related to that of the phenol compounds, where higher phenol compound content was followed by higher antioxidant activity. The total polyphenol content was responsible for the antioxidant activity, A. pauciflorum had the highest antioxidant activity, followed by S. oleana, M. indica, T. cacao and C. burmanii. An investigation of the leaves, peel, stem bar and kernel of mango showed that the total phenolic content ranged from 63.89-11.80 mg GAE g–1 in a distilled water solution and the flavonoid content ranged from 45.56-90.89 mg CE g–1 in a distilled water solution, mangiferin and quercetin were the antioxidants found in mango leaves14,15.

Osman et al.16 stated that cocoa leaves contain polyphenols that consist of epigalo catechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG) and epicatechin (EC). According to Al-Dhubiab17, the dominant polyphenol compounds in C. burmannii are cinnamyl alcohol, coumarin, cinnamic acid, cinnamaldehyde, anthocyanin and essential oil. In addition, Prasad et al.18 analyzed the antioxidant activity of the cinnamon species by high-performance liquid chromatographic analysis combined with an array diode detector (HPLC-DAD) and three flavonoid compounds, quercetin, kaempferol and quercitrin, were observed. According to Anggraini7, the secondary metabolites found in S. oleana are anthocyanins.

Anthocyanin content: Anthocyanins have an optimum absorption at 500 nm, as the basic colours of red, blue and purple in plants are abundant in vegetables and fruits and other plants will degrade these colours at high temperatures to produce high-impact colour changes16. The anthocyanin content of the young leaves studied here can be seen in Table 4.

Table 4 shows that the young leaves of M. indica have the highest anthocyanin levels, while the lowest antioxidant levels are found in A. pauciflorum.

Table 5: pH Values of the jelly drinks

Table 6: Antioxidant activities of jelly drinks

There were differing results for antioxidant activity, A. pauciflorum has the highest antioxidant activity, which means that the antioxidant property in A. pauciflorum is conferred by another polyphenol that is not anthocyanin. Anthocyanins are water-soluble pigments that are naturally present in various plants. This pigment is the colour of fruit blossoms and the leaves of green plants. These pigments have been widely used as natural dyes in various food products and are important antioxidants with health benefits.

The anthocyanin content of these leaves will contribute to the colour of the jelly drink. In addition to appearance, the jelly drink colour has another function, it possesses functional properties due to its antioxidant compounds such as anthocyanin.

Results of the jelly drink analysis: Degree of Acidity (pH): The pH values for jelly drinks containing A. pauciflora, S. oleana, M. indica, T. cacao or C. burmannii young leaves are shown in Table 5.

Anthocyanin is a water-soluble pigment and the stability of factors such as pH (anthocyanin is degraded at pH levels above 7), temperature, light, the absence of co-pigment and the presence of enzymes, oxygen, vitamin C and sugar influences the colour19. Table 4 shows that the acidity of the leaves will contribute to the acidity of the jelly drink. Because all of the fruits have a pH value lower than 7, the addition of acid from another source is unnecessary. S. oleana is the most acidic leaf type.

Antioxidant Activity of Jelly Drinks Containing Leaves of A. pauciflorum, S. oleana, M. indica, T. cacao or C. burmannii: Consumption of jelly drinks containing A. pauciflorum, S. oleana, M. indica, T. cacao or C. burmannii young leaf extracts is associated with health benefits due to the antioxidant activity and presence of polyphenols, including anthocyanin.

Table 7: Total polyphenol content of the jelly drinks

Based on Table 6, the average antioxidant activity of jelly drinks ranged from 10.52-67.56%. The highest antioxidant activity (67.56%) was obtained from the addition of the young leaves of A. pauciflorum. The lowest antioxidant activity (10.52%) was obtained from the addition of young leaves from C. burmannii. Compared with the raw material, the antioxidant activity of the jelly drinks decreases after production, which is caused by antioxidant damage due to oxidation after exposure to air and cooking with high temperatures. In addition, the decrease in antioxidant activity is influenced by the amount of concentrated leaf extract added to the jelly beverage.

Plants contain structurally different antioxidant and antimicrobial phenolic compounds with different characteristics, such as stability. Caffeic, chlorogenic and gallic acid are unstable at a high pH, while chlorogenic acid is stable at an acidic pH under heat20.

Total polyphenol content: Phenolic compounds in jelly drinks that contain various young leaves also contribute directly to antioxidant capacity. The total polyphenol contents of the jelly drinks produced in this study can be seen in Table 7.

Based on Table 7, the average total polyphenol content of a jelly drink containing young leaves ranges from 1095.5-477.5 mg GAE g–1. Compared with the raw material, the total polyphenol content in jelly drinks decreases. This indicates that the processing adversely affects the total polyphenol content. Polyphenols are secondary metabolites of plants that have potential health benefits, as the dietary plant polyphenols offer protection against the development of cancer, cardiovascular diseases and other generative stresses21. Azulene, cylopentacycloheptane, azulene cylopentacycloheptene and phenol 2,2’-methylene bis[6-C1, 1-dimethylethyl]-4 ethyl are compounds found in the methanolic extract of C. burmannii leaves22. Epicatechin, epigallocatechin gallate and epicatechin gallate are the polyphenols present in the young leaves of T. cacao16.

Anthocyanin content: Anthocyanin as a food dye is not only useful for improving the appearance of the product but is also very beneficial for health.

Table 8:Anthocyanin contents of the jelly drinks

Table 9:
Colour of jelly drinks containing young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii

The anthocyanin contents of jelly drinks containing the young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao or C. burmannii are shown in Table 8.

Based on Table 8, the average anthocyanin content of the jelly beverages ranged from 11.79-2.69 mg L–1. Anthocyanin was not significantly degraded at temperatures of 2.5-80°C but will degrade at temperatures above 80°C16. The most interesting characteristics of anthocyanin are its antioxidant and anti-inflammatory properties, which can help reduce the risk of cardiovascular disease and various diseases caused by oxidative stress23.

Anthocyanin contributes to the colour of jelly drinks, the highest anthocyanin content was observed in M. indica extract, followed by S. oleana, A. pauciflorum, T. cacao and C. burmanii. Different results were obtained for their antioxidant activity, the highest antioxidant activity was found in A. pauciflorum. This indicates that anthocyanin does not contribute to the antioxidant activity of A. pauciflorum. Anthocyanin gives a purple colour to the jelly drinks and contributes to their functional properties24,25.

Colour test: Colour is a property of food products that can be viewed as both a physical (objective) and an organoleptic (subjective) property. Colour is also an important attribute affecting the quality of jelly drinks. The colour of the jelly beverages containing natural dyes from various leaf sources was evaluated using a spectrophotometer (Hunterlab ColorFlex EZ), which yielded 3 colour parameters with L*, a* and b* notation. The resulting percentage values of the jelly drinks are presented in Table 9.

Based on Table 9, the colour analysis of jelly drinks is L* and ranges from 19.79-25.42, while a* ranges from -0.74-7.79 and b* ranges from 1.67-10.70. The resulting colour is also influenced by pH, a higher pH value resulted in a redder colour, which will also fade. According to Eiro and Heinonen26, malvidin 3-glucoside solutions have the greatest co-pigmentation reactions, namely, the reaction of rosmarinic acid with malvidin 3-glucoside, which increases the colour intensity by 260%, while the addition of ferulic and caffeic acid increased the intensity of pelargonidin 3-glucoside. Anthocyanin is the major antioxidant of these young leaves, which have a stable condition for the flavylium cation when heated at 95°C at a pH of 1. Anthocyanin aglycones were degraded by scission into cyanidin-triglycosides, pelargonidin and cyanidin27. Therefore, the implication of this study is that the young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii can be applied to food products, but further studies are needed to determine the types of anthocyanin present in each young leaf.

SIGNIFICANCE STATEMENT

This study uncovered the potential for young leaves with red pigments to be used as colourants, which can be beneficial to increase the functional benefits of the plant in its application in food products. This study will help researchers uncover the critical properties of plants that can function as potential colourants, which many researchers have thus far been unable to explore.

CONCLUSION

The young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii show potential as colourants for jelly drinks. The results of this study showed that the antioxidant activity and total polyphenol content of A. pauciflora were the highest among the young leaves in both extracts and jelly drinks. The anthocyanin contents of young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii were 17.90±0.03, 19.34±0.02, 74.39±0.07, 26.84±0.01 and 21.61±0.02 respectively, while the anthocyanin contents in A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii jelly drinks were 6.90±0.02, 7.39±0.03, 11.79±0.04, 11.79±0.04 and 2.69±0.02, respectively. The young leaves of A. pauciflorum, S. oleana, M. indica, T. cacao and C. burmannii can potentially be used in jelly drinks as colourants.

ACKNOWLEDGMENT

This study was funded by the Faculty of Agriculture Technology, Andalas University, West Sumatra Indonesia.

REFERENCES
1:  Bowen-Forbes, C.S., Y. Zhang and M.G. Nair, 2010. Anthocyanin content, antioxidant, anti-inflammatory and anticancer properties of blackberry and raspberry fruits. J. Food Comp. Anal., 23: 554-560.
CrossRef  |  Direct Link  |  

2:  Dai, J., A. Gupte, L. Gates and R.J. Mumper, 2009. A comprehensive study of anthocyanin-containing extracts from selected blackberry cultivars: Extraction methods, stability, anticancer properties and mechanisms. Food Chem. Toxicol., 47: 837-847.
CrossRef  |  Direct Link  |  

3:  Kamaljeet, S. Bansal and U. SenGupta, 2017. A study of the interaction of bovine hemoglobin with synthetic dyes using spectroscopic techniques and molecular docking. Front. Chem., Vol. 4. 10.3389/fchem.2016.00050

4:  Pivtsaev, A.A. and V.I. Razov, 2016. Detection of the carcinogenic properties of synthetic and natural dyes using positron annihilation lifetime spectrometry. Toxicol. Res., 5: 1306-1308.
CrossRef  |  Direct Link  |  

5:  Hii, C.L., C.L. Law, S. Suzannah, Misnawi and M. Cloke, 2009. Polyphenols in cocoa (Theobroma cacao L.). Asian J. Food Agro-Ind., 2: 702-722.
Direct Link  |  

6:  Ramirez, N.M., L.M. Farias, F.A. Santana, J.P.V. Leite and M.I. De Souza Dantas et al., 2016. Extraction of mangiferin and chemical characterization and sensorial analysis of teas from Mangifera indica L. leaves of the uba variety. Beverages, Vol. 2, No. 4. 10.3390/beverages2040033

7:  Anggraini, T., 2017. Antioxidant activity of Syzygium oleana. Pak. J. Nutr., 16: 605-611.
CrossRef  |  Direct Link  |  

8:  Blois, M.S., 1958. Antioxidant determinations by the use of a stable free radical. Nature, 181: 1199-1200.
CrossRef  |  Direct Link  |  

9:  Wang, H., G.J. Provan and K. Helliwell, 2000. Tea flavonoids: Their functions, utilisation and analysis. Trends Food Sci. Technol., 11: 152-160.
CrossRef  |  Direct Link  |  

10:  Lee, J., R.W. Durst and R.E. Wrolstad, 2005. Determination of total monomeric anthocyanin pigment content of fruit juices, beverages, natural colorants and wines by the pH differential method: Collaborative study. J. AOAC Int., 88: 1269-1278.
Direct Link  |  

11:  Castaneda-Ovando, A., M. de Lourdes Pacheco-Hernandez, M.E. Paez-Hernandez, J.A. Rodriguez and C.A. Galan-Vidal, 2009. Chemical studies of anthocyanins: A review. Food Chem., 113: 859-871.
CrossRef  |  Direct Link  |  

12:  Muselik, J., M. Garcia-Alonso, M.P. Martin-Lopez, M. Zemlicka and J.C. Rivas-Gonzalo, 2007. Measurement of antioxidant activity of wine catechins, procyanidins, anthocyanins and pyranoanthocyanins. Int. J. Mol. Sci., 8: 797-809.
CrossRef  |  Direct Link  |  

13:  Hartati, S., C. Aoki, M. Hanafi, M. Angelina, P. Soedarmono and H. Hotta, 2018. Antiviral effect of Archidendron pauciflorum leaves extract to hepatitis C virus: An in vitro study in JFH-1 strain. Med. J. Indonesia, 27: 12-18.
CrossRef  |  Direct Link  |  

14:  Sultana, B., Z. Hussain, M. Asif and A. Munir, 2012. Investigation on the antioxidant activity of leaves, peels, stems bark and kernel of mango (Mangifera indica L.). J. Food Sci., 77: C849-C852.
CrossRef  |  Direct Link  |  

15:  Fernandez-Ponce, M.T., L. Casas, C. Mantell, M. Rodriguez and E.M. de la Ossa, 2012. Extraction of antioxidant compounds from different varieties of Mangifera indica leaves using green technologies. J. Supercrit. Fluids, 72: 168-175.
CrossRef  |  Direct Link  |  

16:  Osman, H., R. Nasarudin and S.L. Lee, 2004. Extracts of cocoa (Theobroma cacao L.) leaves and their antioxidation potential. Food Chem., 86: 41-46.
CrossRef  |  Direct Link  |  

17:  Al-Dhubiab, B.E., 2012. Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii. Pharmacogn. Rev., 6: 125-131.
CrossRef  |  Direct Link  |  

18:  Prasad, K.N., B. Yang, X. Dong, G. Jiang, H. Zhang, H. Xie and Y. Jiang, 2009. Flavonoid contents and antioxidant activities from Cinnamomum species. Innovative Food Sci. Emerg. Technol., 10: 627-632.
CrossRef  |  Direct Link  |  

19:  Patras, A., N.P. Brunton, C. O'Donnell and B.K. Tiwari, 2010. Effect of thermal processing on anthocyanin stability in foods; mechanisms and kinetics of degradation. Trends Food Sci. Technol., 21: 3-11.
CrossRef  |  Direct Link  |  

20:  Cavalcanti, R.N., D.T. Santos and M.A.A. Meireles, 2011. Non-thermal stabilization mechanisms of anthocyanins in model and food systems-An overview. Food Res. Int., 44: 499-509.
CrossRef  |  Direct Link  |  

21:  Friedman, M. and H.S. Jurgens, 2000. Effect of pH on the stability of plant phenolic compounds. J. Agric. Food Chem., 48: 2101-2110.
CrossRef  |  Direct Link  |  

22:  Pandey, K.B. and S.I. Rizvi, 2009. Plant polyphenols as dietary antioxidants in human health and disease. Oxidative Med. Cell. Longevity, 2: 270-278.
CrossRef  |  Direct Link  |  

23:  Darmadi, A.A.K., D.N. Suprapta, I.G.R.M. Temaja and I.M.D. Swantara, 2017. GC-MS analysis of active compounds of cinnamon leaf extracts (Cinnamomum burmanni Blume). Int. J. Pharm. Bio Sci., 8: 409-415.
CrossRef  |  Direct Link  |  

24:  Martynenko, A. and Y. Chen, 2016. Degradation kinetics of total anthocyanins and formation of polymeric color in blueberry hydrothermodynamic (HTD) processing. J. Food Eng., 171: 44-51.
CrossRef  |  Direct Link  |  

25:  Miguel, M.G., 2011. Anthocyanins: Antioxidant and/or anti-inflammatory activities. J. Applied Pharm. Sci., 1: 7-15.
Direct Link  |  

26:  Eiro, M.J. and M. Heinonen, 2002. Anthocyanin color behavior and stability during storage:‚ÄČ Effect of intermolecular copigmentation. J. Agric. Food Chem., 4: 7461-7466.
CrossRef  |  Direct Link  |  

27:  Sadilova, E., F.C. Stintzing and R. Carle, 2006. Thermal degradation of acylated and nonacylated anthocyanins. J. Food Sci., 71: C504-C512.
CrossRef  |  Direct Link  |  

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