Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea
Ishizuchi dark tea, a traditional Japanese post-fermented tea, has attracted considerable attention for its bioactivity. In this study, the effect of water hardness on Ishizuchi dark tea infusions was analyzed. Sensory testing revealed that the teas brewed in hard water were less sour in taste than...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-10-01
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| Series: | Food Chemistry Advances |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2772753X23000734 |
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| author | Chihiro Minamoto Raon Kondo Masaki Shiomi Akihisa Kita Ayuka Tagashira Satoshi D. Ohmura Tsuyoshi Matsuki Jun Yano Kosuke Nishi Takuya Sugahara Kanji Tomioka |
| author_facet | Chihiro Minamoto Raon Kondo Masaki Shiomi Akihisa Kita Ayuka Tagashira Satoshi D. Ohmura Tsuyoshi Matsuki Jun Yano Kosuke Nishi Takuya Sugahara Kanji Tomioka |
| author_sort | Chihiro Minamoto |
| collection | DOAJ |
| description | Ishizuchi dark tea, a traditional Japanese post-fermented tea, has attracted considerable attention for its bioactivity. In this study, the effect of water hardness on Ishizuchi dark tea infusions was analyzed. Sensory testing revealed that the teas brewed in hard water were less sour in taste than those brewed in soft water. The most abundant organic acid found in the tea infusions was lactic acid, with a constant concentration of 4 mmol L−1, regardless of water hardness. The pH of the tea infusions increased from 4 to 5 with increasing water hardness, and a similar increase in pH was observed with increasing concentrations of Ca2+ (or Mg2+) and HCO32− in an aqueous solution of 4 mmol L−1 lactic acid. The antioxidative activity of the tea infusion was clearly independent of water hardness. Therefore, hard water is suitable for brewing Ishizuchi dark tea because tea brewed in hard water has a less sour taste, which is more favored, while maintaining the same degree of antioxidative ability. |
| first_indexed | 2024-03-13T03:27:05Z |
| format | Article |
| id | doaj.art-388450d8f87d436980176dab7b465d22 |
| institution | Directory Open Access Journal |
| issn | 2772-753X |
| language | English |
| last_indexed | 2024-03-13T03:27:05Z |
| publishDate | 2023-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Food Chemistry Advances |
| spelling | doaj.art-388450d8f87d436980176dab7b465d222023-06-25T04:44:47ZengElsevierFood Chemistry Advances2772-753X2023-10-012100253Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark teaChihiro Minamoto0Raon Kondo1Masaki Shiomi2Akihisa Kita3Ayuka Tagashira4Satoshi D. Ohmura5Tsuyoshi Matsuki6Jun Yano7Kosuke Nishi8Takuya Sugahara9Kanji Tomioka10Department of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, Japan; Corresponding author.Department of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, JapanDepartment of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, JapanDepartment of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, JapanDepartment of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, JapanDepartment of Applied Chemistry and Biotechnology, National Institute of Technology (KOSEN), Niihama College, 7-1 Yagumo-cho, Niihama-shi Ehime 7928580, JapanDepartment of Electronics and Control Engineering, KOSEN, Niihama College, JapanFaculty of Fundamental Science, KOSEN, Niihama College, JapanFaculty of Agriculture, Ehime University, JapanFaculty of Agriculture, Ehime University, JapanDepartment of Applied Chemistry and Biotechnology, KOSEN, Kurume College, JapanIshizuchi dark tea, a traditional Japanese post-fermented tea, has attracted considerable attention for its bioactivity. In this study, the effect of water hardness on Ishizuchi dark tea infusions was analyzed. Sensory testing revealed that the teas brewed in hard water were less sour in taste than those brewed in soft water. The most abundant organic acid found in the tea infusions was lactic acid, with a constant concentration of 4 mmol L−1, regardless of water hardness. The pH of the tea infusions increased from 4 to 5 with increasing water hardness, and a similar increase in pH was observed with increasing concentrations of Ca2+ (or Mg2+) and HCO32− in an aqueous solution of 4 mmol L−1 lactic acid. The antioxidative activity of the tea infusion was clearly independent of water hardness. Therefore, hard water is suitable for brewing Ishizuchi dark tea because tea brewed in hard water has a less sour taste, which is more favored, while maintaining the same degree of antioxidative ability.http://www.sciencedirect.com/science/article/pii/S2772753X23000734Dark teaWater hardnesspHSensory testingAntioxidative activity |
| spellingShingle | Chihiro Minamoto Raon Kondo Masaki Shiomi Akihisa Kita Ayuka Tagashira Satoshi D. Ohmura Tsuyoshi Matsuki Jun Yano Kosuke Nishi Takuya Sugahara Kanji Tomioka Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea Food Chemistry Advances Dark tea Water hardness pH Sensory testing Antioxidative activity |
| title | Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea |
| title_full | Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea |
| title_fullStr | Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea |
| title_full_unstemmed | Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea |
| title_short | Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea |
| title_sort | effects of water hardness on the flavor and antioxidant activity of ishizuchi dark tea |
| topic | Dark tea Water hardness pH Sensory testing Antioxidative activity |
| url | http://www.sciencedirect.com/science/article/pii/S2772753X23000734 |
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