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Effect of Extraction pH on Hydrangenol Content in Hydrangea Tea
Eun-Seo Beak1, Ha-Rin Park1, Myo-Jeong Kim1,2
1Institute for Digital Antiaging Healthcare, Inje University, Gyeongnam 50834, Korea.
Preventive Nutrition and Food Science
|November 3, 2025
Summary
Optimizing hydrangea tea extraction with acidic conditions significantly boosts hydrangenol content. Adding ingredients like calamansi further enhances hydrangenol yield, improving this bioactive compound
Area of Science:
- Food Chemistry
- Phytochemistry
- Beverage Science
Background:
- Hydrangea tea possesses a distinct sweet flavor and contains valuable bioactive compounds like phyllodulcin and hydrangenol.
- Understanding factors influencing hydrangenol content is crucial for maximizing its yield in tea extracts.
Purpose of the Study:
- To identify key factors, such as water type and pH, affecting hydrangenol concentration in hydrangea tea.
- To develop strategies for increasing hydrangenol yield through optimized extraction conditions and blending materials.
Main Methods:
- Tea extracts were prepared under diverse conditions and analyzed using high-performance liquid chromatography (HPLC).
- The impact of different water types, pH levels (4.0–7.0), and blending materials (ascorbic acid, dried fruits) on hydrangenol content was evaluated.
Main Results:
- Weakly acidic distilled water yielded the highest hydrangenol concentration (14.36 µg/mL), 10.9 times greater than neutral mineral water.
- Hydrangenol content increased as extraction pH decreased; calamansi as a blending material resulted in the highest yield (21.38 µg/mL).
- HPLC analysis confirmed rapid conversion of hydrangenol to hydrangeic acid under neutral and alkaline conditions.
Conclusions:
- Extraction pH is a critical determinant of hydrangenol yield in hydrangea tea.
- Incorporating pH-lowering blending materials, such as calamansi, effectively enhances hydrangenol production in hydrangea tea extracts.
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