Presentation Type
Poster Presentation
Abstract
This study investigated the effects of ultraviolet (UV) light disinfection on key bioactive flavonoid compounds in rooibos tea (Aspalathus linearis). There is an interest in non-thermal food preservation technologies, and UV treatment offers potential advantages for beverage processing. However, concerns exist regarding possible degradation of health-promoting compounds during treatment. Rooibos tea samples were subjected to five UV exposure intensities (0, 25, 50, 75, and 100 mJ/cm²), and concentrations of four major flavonoids (aspalathin, orientin, vitexin, and rutin) were measured using high performance liquid chromatography (HPLC). Surprisingly, most flavonoids showed stability or slight concentration increases at higher UV doses. Aspalathin concentrations increased by approximately 10% at the highest UV doses (75-100 mJ/cm²), while orientin showed the most pronounced response with a 55% increase at 100 mJ/cm². Vitexin remained exceptionally stable across all treatments with only 4% variation, while rutin exhibited a moderate 10% increase at 100 mJ/cm². These findings suggest that UV disinfection at typical treatment doses does not significantly degrade key bioactive compounds in rooibos tea and may potentially enhance extraction or bioavailability of certain flavonoids.
Faculty Mentor
Matthew J. Vergne
Recommended Citation
Ghanem, Sora; Ankiah, Leah; and Ahmed, Yusra, "Spilling the Tea: Effects of UV Disinfection on Bioactive Compounds in South African Rooibos Tea" (2025). Student Scholar Symposium. 117.
https://digitalcollections.lipscomb.edu/student_scholars_symposium/2025/Full_schedule/117
Included in
Analytical Chemistry Commons, Biotechnology Commons, Food Science Commons, Pharmacy and Pharmaceutical Sciences Commons
Spilling the Tea: Effects of UV Disinfection on Bioactive Compounds in South African Rooibos Tea
This study investigated the effects of ultraviolet (UV) light disinfection on key bioactive flavonoid compounds in rooibos tea (Aspalathus linearis). There is an interest in non-thermal food preservation technologies, and UV treatment offers potential advantages for beverage processing. However, concerns exist regarding possible degradation of health-promoting compounds during treatment. Rooibos tea samples were subjected to five UV exposure intensities (0, 25, 50, 75, and 100 mJ/cm²), and concentrations of four major flavonoids (aspalathin, orientin, vitexin, and rutin) were measured using high performance liquid chromatography (HPLC). Surprisingly, most flavonoids showed stability or slight concentration increases at higher UV doses. Aspalathin concentrations increased by approximately 10% at the highest UV doses (75-100 mJ/cm²), while orientin showed the most pronounced response with a 55% increase at 100 mJ/cm². Vitexin remained exceptionally stable across all treatments with only 4% variation, while rutin exhibited a moderate 10% increase at 100 mJ/cm². These findings suggest that UV disinfection at typical treatment doses does not significantly degrade key bioactive compounds in rooibos tea and may potentially enhance extraction or bioavailability of certain flavonoids.