Comparative study of phenolic profile, antioxidant and antimicrobial activities of aqueous extract of white and green tea

Abstract

The sole difference between white tea (WT) and green tea (GT) is the former that made only from the buds and young leaves of the Camelia sinensis plant, whilst the latter is made from matured tea leaves. The phytochemical profiles, phenolic compounds, antioxidant, and antimicrobial activity of two varieties of Camellia sinensis teas, white and green, were compared in this study. Total antioxidant capacity, reducing power, DPPH radical scavenging, and Fe+2 chelating activities were used to determine antioxidant activities in water extract of GT and WT. The largest level of phenolic content was discovered in WGTE compared with the lowest amount was found in WWTE (290.67 mg/100 g tea and 185.96 mg/100 g tea, respectively). Phenoilc acids (gallic, benzoic, chlorogenic, ellagic, and ρ-coumaric acids) and flavonoids (rutin and kampherol) were found in the two extracts. The findings of DPPH radical scavenging assays were 84.06 and 82.37% inhibition. In vitro antimicrobial activity was indicated that (WWTE and WGTE) had a high level of activity against Staphylococcus aureus, and gave negative activity against Salmonella typhimurium, and Aspergillus Niger. The WT and GT extracts are a great source of natural antioxidants with biological effects on human health.

Tea and Pleurotus ostreatus intercropping modulates structure of soil and root microbial communities

“…Aqueous extract (AE) content was determined by the full weight method according to the guidelines of the Chinese national standards GB/T8305-2013 44 . Flavonoids were determined using the aluminum trichloride method as described by Zhang et al 45 .…”

Detoxifying Cyanides Using Cyanase Enzyme Complexes Composed of Carbonic Anhydrase via Irreversible Covalent Bonds

“…However, chlorination of cyanide can cause additional environmental problems as it produces highly toxic intermediates, such as cyanogen chloride and other toxic organochlorines. Therefore, eco-friendly methods such as using activated sludge or microorganisms with chemical treatment are adopted, 10,11 but these also have the disadvantage of weakening the survival and activity of microorganisms through the high concentration of cyanide in industrial wastewater. 12 Biodegradative routes can be catalyzed by different types of enzymes, including cyanase, cyanide hydratases, cyanidases (cyanide dihydratases), cyanide mono-and dioxygenases, rhodaneses, 3-cyanoalanine synthases/hydratases, nitrilases, or nitrile hydratases.…”

“…However, chlorination of cyanide can cause additional environmental problems as it produces highly toxic intermediates, such as cyanogen chloride and other toxic organochlorines. Therefore, eco-friendly methods such as using activated sludge or microorganisms with chemical treatment are adopted, , but these also have the disadvantage of weakening the survival and activity of microorganisms through the high concentration of cyanide in industrial wastewater …”