Curcuma longa L. plant residue as a source for natural cellulose fibers with antimicrobial activity

Natural cellulose fibers extracted from stems of Curcuma longa L. have properties similar to fibers from lignocellulosic crop residues and also inherit antimicrobial properties. Turmeric contains curcumin, the natural compound known to have many medicinal benefits including anti-cancer activity. Turmeric plants are mainly cultivated for its rhizome (tuber) but the plant generates considerable amounts of stem and leaves as residues. Leaves and stems of turmeric plants have been reported to contain oil and other extractives having antimicrobial and anti-insecticidal activities. Such extracts are of limited quantity and hence it is difficult to justify the economic feasibility of using the residues for large scale applications. Natural fibers have a large market and offer higher value addition and options to develop various products. However, fibers obtained from lignocellulosic sources do not have inherent antimicrobial properties. Turmeric stems were treated with alkali solution to obtain natural cellulose fiber bundles. These fibers had cellulose content of about 50%, lignin content of 12% and about 10% ash. Alkali treatment removed surface substances resulting in smooth fiber bundles. Cellulose in the fibers showed typical diffraction peak at 22.7 degrees belonging to the 002 plane. Tensile strength of the fibers at 2.5 g/den (325 MPa) was similar to jute. Fibers showed antimicrobial activity against both gram positive and gram negative bacteria. Turmeric fibers could be useful for wound dressings, textiles, composites and other applications.