Enzyme-assisted extraction for enhanced yields of turmeric oleoresin and its constituents

•Enzyme-assisted extraction of turmeric oleoresin was carried out using acetone.•Process parameters were optimised to get maximum yield of the extractives.•Enzymatic pretreatment of turmeric powder increased the oleoresin yield by 22.5%.•Yield of curcumin increased by 31.83% on enzymatic pretreatment of turmeric powder.•An increase in yield of volatile oil by 70% was also observed.

In the present study, enzyme-assisted extraction of turmeric oleoresin was carried out using acetone as a solvent. The enzymes used for the pretreatment of turmeric prior to solvent extraction were α-amylase, glucoamylase, and a commercial mixture of enzymes containing cellulase and xylanase. The oleoresins were quantified for the content of curcumin and volatile oil after each extraction. Process parameters such as enzyme concentration, pH, incubation time and time of extraction were optimised to get maximum yield of the extractives. An increase of 13.7% and 22.5% oleoresin and 26.04% and 31.83% increase in curcumin yield were observed on enzymatic pretreatment of the turmeric powder by α-amylase and glucoamylase, respectively. The yield of volatile oil also increased significantly by 70% and 53.75% after α-amylase and glucoamylase pretreatment suggesting the feasibility of this process.