Studies on Polyphenol content, flavonoid content, and antioxidant activity of Graviola tea pulp (Annona muricata L.)

Abstract

Tea is the most commonly consumed beverage worldwide due to promote health and prevention of some human diseases. Soursop tea pulp is well-known for containing a significant content of ascorbic acid (TAA), polyphenols (TPC) and flavonoids (TFC). In the present study, different pulp tea samples with varying dates of production were checked for TAA, TPC, TFC, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activities, followed by sensory evaluation. There is a difference in TAA between sample (1) and (4), achieved 7.43 ± 0.04 mg/g DM and 12.21 ± 0.04 mg/g DM, respectively. TFC content ranged between 0.13 and 0.18. The phenolics group in tea is high and there are differences between the 3 recent production samples with (1): 3.81mg QC/g DM fluctuation. In sample 1, the antioxidant activity of the ethanol extract of Soursop was correlated with total phenolic and flavonoid content with values of 0.26 mgAA /g DM, 2.61 mgAA /g DM for DPPH and ABTS scavenging activity, respectively. Moreover, the CIE Lab* color space of the soursop tea is measured in the dark area, the L * difference achieved at 30.82 ± 1.24 (2) lowest and the highest 37.42 ± 4.77 (1). Consumer sensory evaluation is performed with results based on a 5-point scale describing: flavor, aroma, color, and favorite. The results showed sensory acceptance of all four samples and neligible difference in scores.