Quantification of polyphenol, antioxidant, and antibacterial from red and purple roselle calyces using maceration extraction under different solvent conditions

Abstract

This research was conducted to extract polyphenols, antioxidants, and antimicrobial red and purple roselle calyces (Hibiscus sabdariffa L.) with maceration techniques using different types of solvents. Total polyphenols were determined using the Folin-Ciocalteu method. The antioxidant activity was expressed as the DPPH reduction, and antimicrobial activity were evaluated against the Staphylococcus aureus and Escherichia coli bacterial strains. The most significant extraction yield was obtained using ethanol at a concentration level of 80% in two rosella varieties (red and purple). In contrast, the polyphenol content of purple roselle was relatively higher than that of red roselle. The maximum total polyphenols in the extraction process in purple roselle with methanol 80% (27.60 mg GAE/g), while the minimum phenolic (9.50 mg GAE/g extract) in red roselle with 50% ethyl acetate solvent. The antioxidant activity increased in the antioxidant test, where 80% methanol extract showed the highest scavenging antioxidant activity, 73.84 ± 0.53% and 62.80 ± 1.57% for purple and red roselle calyces. The inhibition zone was obtained against E. Coli (13.45 ± 3.30 mm) on the purple roselle, and the inhibition zone was obtained for S. aureus (11,4 ± 0,04) on the red roselle. It was concluded that red and purple roselle calyces are a prospective source of antioxidant and antimicrobial phenolic compounds.