Optimization of Total Phenolics Content and Total Antioxidant Activity of Black Tea Using Response Surface Methodology

Abstract

Response surface methodology was used to optimize the fermentation conditions for the total phenolics content and antioxidant activity of black tea (Camellia sinensis). Fresh tea leaves were fermented following a rotatable central composite design of eleven experiments replicated thrice. The minimum and maximum fermentation time and temperature were respectively of 1 - 3 h and 30 - 40 °C. The results demonstrated that fermentation time and temperature significantly affect the total phenolics content and antioxidant activity of black tea. The optimum fermentation conditions for the present study were at 36 °C for 35 min which the values for total phenolics content and total antioxidant activity were 38.99 g GAE/100 g dw and 19.74 mg VitC Eq/100 g dw, respectively. Antioxidant activity was strongly correlated with total phenolics content of black tea.

Biochemical investigation of Bangladeshi black tea and their correlation to organoleptic quality evaluation

“…Both TPC and HPS increase during oxidation. Proteolytic enzymes increase the antioxidant activity of tea by hydrolysing phenolic compounds into free phenols through fermentation (oxidation) [ 12 ].…”

Optimization of the factors affecting BT-2 black tea fermentation by observing their combined effects on the quality parameters of made tea using Response Surface Methodology (RSM)

“…Moreover, the proteolytic enzymes during fermentation hydrolyze phenolic complexes into soluble-free phenols and more biologically active phenols. The bioconversion of phenolic compounds from their conjugated to free forms during fermentation enhances their antioxidant activity (Tiku et al, 2017). However, depending on the fermentation process, TPC in black tea can vary significantly (Zareef et al, 2019).…”