Fractionation of sugarcane molasses distillery wastewater and evaluation of antioxidant and antimicrobial characteristics

Sugarcane molasses distillery wastewater (DWW) was fractionated by ultrafiltration (UF) using 100 kDa and 10 kDa membranes. The isolated fractions were characterized for antioxidant activity and content of melanoidins, total phenols, proteins and carbohydrates were measured. Chemical composition of the fractions was determined using GC MS analysis and antimicrobial property was tested against pure microbial cultures. DWW has high antioxidant activity with the melanoidins content around 2 x 10(3) times the total phenols content. Diafiltration leads to loss in antioxidant activity. Removing the bound melanoidins compounds from the pure melanoidins core does not affect the antioxidant activity. Among all fractions, the highest antioxidant activity is shown by the > 100 kDa fraction without diafiltration. Ethanol fractionation of > 100 kDa fraction further separates phenols and melanoidins rich fractions from its structure. Ethanol soluble fraction shows high phenols content while the precipitate or aqueous fraction has high melanoldins and carbohydrate content. Antimicrobial potency is mainly observed in arginine rich > 100 kDa fraction against Bacillus lichenifonnis.