Enhancement of xylooligosaccharides production as a novel antioxidant source through autoclave-assisted oxalic acid pretreatment of sugarcane trash

Abstract

This study explores enhancing xylooligosaccharides (XOS) production as a novel source of antioxidants by utilizing autoclave-assisted oxalic acid pretreatment of sugarcane trash, specifically its tops and leaves. The study aims to optimize the concentration of oxalic acid and the duration of heating to maximize XOS yield and antioxidant activity, while also considering phenolic content as a contributing factor. Initially, through a One Factor at a Time (OFAT) approach, different concentrations of oxalic acid (ranging from 0.5 to 3%) were tested with a consistent 30-min heating period. The optimal XOS level of 6.45 g/L and 70.23% antioxidant activity was achieved at a 1% acid concentration. Subsequently, the focus shifted to optimizing heating durations (30, 45, and 60 min) at the identified optimal acid concentration. The highest XOS concentration of 6.45 g/L was observed at 30 min, while the peak antioxidant activity of 73.32% was attained at 60 min. Moreover, the total phenolic content of XOS, which contributes to its antioxidant properties, was found to be in the range of 9–10 mg GAE/100 mg. These findings highlight the potential of sugarcane trash as a new biomass resource for the production of antioxidant-rich XOS.