The catechins profile and antioxidant activity in different types of green tea bags
Tea and mainly green tea as a rich source of antioxidants has been widely known for some time. The antioxidant capacity of tea including green tea is mainly due to its catechins content. The objective of this study was to determine the relationship between the ORAC value and the catechins content....
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| Format: | Article |
| Language: | Arabic |
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collage of education / university of Misan
2020-05-01
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| Series: | مجلة ابحاث ميسان |
| Subjects: | |
| Online Access: | https://uomisan.edu.iq/eduweb/jmr/index.php/jmr/article/view/32 |
| _version_ | 1827761586455969792 |
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| author | ez al-Din Khazal Najm Al-Zubaidi |
| author_facet | ez al-Din Khazal Najm Al-Zubaidi |
| author_sort | ez al-Din Khazal Najm Al-Zubaidi |
| collection | DOAJ |
| description | Tea and mainly green tea as a rich source of antioxidants has been widely known for some time. The antioxidant capacity of tea including green tea is mainly due to its catechins content. The objective of this study was to determine the relationship between the ORAC value and the catechins content. Regular and decaffeinated commercial green tea bags commonly consumed in the United Kingdom (UK) have been examined using Reversed-Phase High-pressure Liquid Chromatography (RP-HPLC). Teabags were purchased from different local supermarkets in the UK and extracted with natural mineral water at temperature 100°C for 9 minutes at the pre-adjusted pH 4. The level of four catechins (Epi-structured) for the thirteen types of green tea were separated and determined by HPLC analysis, i.e. ()-epigallocatechin (EGC), ()-epicatechin (EC), ()-epigallocatechin-3-gallate (EGCG) and ()-epicatechin gallate (ECG). The standard graphs were validated using certified reference catechins supplied by the Laboratory of the Government Chemist (LGC). The levels of total catechins and oxygen radical absorbance capacity (ORAC) values varied from 34.61to 204.55 mg/g, 830.19- 4197.81 Trolox equivalents/g tea bags for thirteen types of green teas respectively. It was clear from the results of this study that there was a significant linear and positive correlation (r = 0.951, df = 12, p < 0.05) is found to exist between the total catechins contents and ORAC values. It can be concluded that the results of catechins measurements coupled to this; the well-known ORAC assay was successfully modified to measure the antioxidant capacity of the green tea extracts throughout this study. Furthermore, the higher the level of catechins the higher is the antioxidant capacity of the tea. This may stimulus consumers in selecting the type of tea and tea brewing times, exhibiting more health benefits. Nevertheless, the differences between the studied brands are owing to shelf life, production and storage conditions.
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| first_indexed | 2024-03-11T10:15:01Z |
| format | Article |
| id | doaj.art-a9ea993fd2ed428487fb49275f4130e6 |
| institution | Directory Open Access Journal |
| issn | 1815-6622 2789-7354 |
| language | Arabic |
| last_indexed | 2024-03-11T10:15:01Z |
| publishDate | 2020-05-01 |
| publisher | collage of education / university of Misan |
| record_format | Article |
| series | مجلة ابحاث ميسان |
| spelling | doaj.art-a9ea993fd2ed428487fb49275f4130e62023-11-16T10:12:35Zaracollage of education / university of Misanمجلة ابحاث ميسان1815-66222789-73542020-05-01163110.52834/jmr.v16i31.32The catechins profile and antioxidant activity in different types of green tea bagsez al-Din Khazal Najm Al-Zubaidi0College of Basic EducationTea and mainly green tea as a rich source of antioxidants has been widely known for some time. The antioxidant capacity of tea including green tea is mainly due to its catechins content. The objective of this study was to determine the relationship between the ORAC value and the catechins content. Regular and decaffeinated commercial green tea bags commonly consumed in the United Kingdom (UK) have been examined using Reversed-Phase High-pressure Liquid Chromatography (RP-HPLC). Teabags were purchased from different local supermarkets in the UK and extracted with natural mineral water at temperature 100°C for 9 minutes at the pre-adjusted pH 4. The level of four catechins (Epi-structured) for the thirteen types of green tea were separated and determined by HPLC analysis, i.e. ()-epigallocatechin (EGC), ()-epicatechin (EC), ()-epigallocatechin-3-gallate (EGCG) and ()-epicatechin gallate (ECG). The standard graphs were validated using certified reference catechins supplied by the Laboratory of the Government Chemist (LGC). The levels of total catechins and oxygen radical absorbance capacity (ORAC) values varied from 34.61to 204.55 mg/g, 830.19- 4197.81 Trolox equivalents/g tea bags for thirteen types of green teas respectively. It was clear from the results of this study that there was a significant linear and positive correlation (r = 0.951, df = 12, p < 0.05) is found to exist between the total catechins contents and ORAC values. It can be concluded that the results of catechins measurements coupled to this; the well-known ORAC assay was successfully modified to measure the antioxidant capacity of the green tea extracts throughout this study. Furthermore, the higher the level of catechins the higher is the antioxidant capacity of the tea. This may stimulus consumers in selecting the type of tea and tea brewing times, exhibiting more health benefits. Nevertheless, the differences between the studied brands are owing to shelf life, production and storage conditions. https://uomisan.edu.iq/eduweb/jmr/index.php/jmr/article/view/32Camellia sinensisCatechinsAntioxidant CapacityGreen Teadecaffeinated |
| spellingShingle | ez al-Din Khazal Najm Al-Zubaidi The catechins profile and antioxidant activity in different types of green tea bags مجلة ابحاث ميسان Camellia sinensis Catechins Antioxidant Capacity Green Tea decaffeinated |
| title | The catechins profile and antioxidant activity in different types of green tea bags |
| title_full | The catechins profile and antioxidant activity in different types of green tea bags |
| title_fullStr | The catechins profile and antioxidant activity in different types of green tea bags |
| title_full_unstemmed | The catechins profile and antioxidant activity in different types of green tea bags |
| title_short | The catechins profile and antioxidant activity in different types of green tea bags |
| title_sort | catechins profile and antioxidant activity in different types of green tea bags |
| topic | Camellia sinensis Catechins Antioxidant Capacity Green Tea decaffeinated |
| url | https://uomisan.edu.iq/eduweb/jmr/index.php/jmr/article/view/32 |
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