Effects of Different Drying Methods on Phenolic and Flavonoid Contents and Determination of Antioxidant Capacity of Guyabano (Annonamuricata) Formulated Tea Leaf

Eure Ka Amithyst  M. Granada,

Effects of Different Drying Methods on Phenolic and Flavonoid Contents and Determination of Antioxidant Capacity of Guyabano (Annonamuricata) Formulated Tea Leaf

Abstract:

This study aimed to assess the effects of different drying methods (oven-, sun-, air- and freeze-drying) on the total phenolic content (TPC), total flavonoid content (TFC), and anti-oxidant capacity of Guyabano (Annonamuricata) formulated tea leaf. Spectrophotometric methods such as Folin-Ciocalteu assay and Aluminum Chloride assay were used for the analysis of phenolic and flavonoid content, respectively. DPPH Radical Scavenging Assay was performed to measure the antioxidant ability of the pre-treated plant material to act as radical scavengers as compared commercial guyabano tea. Thermal drying methods (oven- and sun-drying) resulted into notable decline in both phenolic and flavonoid contents. On non-thermal drying methods, significant losses were observed in air-dried leaves. Freeze -drying method preserved the highest levels of phenolic and flavonoid contents in aqueous extracts of dried Guyabano (Annonamuricata) leaves. In conclusion, among all drying methods used in the study, freeze-drying method was found to be the most efficient in maintaining relatively high levels of total phenolic content (TPC), total flavonoid content (TFC). Moreover, there is a significant difference on the antioxidant activity of commercial guyabano tea and formulated guyabano (Annonamuricata) tea leaf in terms of antioxidant capacity in DPPH assay. Formulated guyabano tea had a potential antioxidant agent based on the determined IC50 values. However, its effect was lower as compared to commercial guyabano tea specifically at 15min infusion time.