Citral enrichment in Lemongrass (Cymbopogon flexuosus) oil using spinning band equipped high vacuum distillation column and sensory evaluation of fractions

Abstract

Citral is the major constituent of Lemongrass oil (LGO) and has various application in the food, cosmetic and pharmaceutical industry. The present study was focused on enhancement of citral content in LGO employing spinning band column equipped high vacuum fractional distillation setup. The collected fractions were investigated for volatile composition using gas chromatography-mass spectrometry (GC–MS), antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and antibacterial activity against Gram-positive and Gram-negative bacteria. The total citral content varied from 1.90 to 88% in various fractions with highest in major fraction, residue experiment-B (RSD, Ex-B, 88%) with collection of 63 mL. RSD, Ex-B demonstrated the lowest IC50 value of 6.77±0.42µL/mL with 55.84 percent inhibition. Further, strong inhibition was demonstrated by RSD, Ex-B against all tested bacterial strains. The sensory analysis revealed that Lemongrass leaves were dominated with lemony, fresh and grassy; LGO with lemony and fresh; and RSD (Ex-B) with lemony, sweet and fresh notes. The distillation process changed the overall aroma profile of RSD (Ex-B) by eliminating grassy and off odors and makes it useful product for flavor and fragrance application. Citral rich fractions have high economic value as well as application in food industry as a flavor, preservative; in home care and self-hygiene products.

Keywords

• Lemongrass
• Essential oil
• Spinning band
• Vacuum fractional distillation
• Antibacterial
• Antioxidant