Upscaling the cymbopogon citratus (lemongrass) extraction process to obtain optimum alpha-glucosidase inhibitor (AGI) levels

Abstract

Cymbopogon citratus (lemongrass) has a great potential to be commercialized as an anti-diabetic medication due to its alpha glucosidase inhibitor (AGI) activity. To achieve this goal, this paper continues the study of extraction optimization at the pilot scale to determine the effect of sample quantities on AGI activity. This experiment comprised three phases: designing the percolator, optimizing the process parameters and conditions, and determining the correlation between various sample quantities and AGI activity. The effects of macerating the plant material prior to percolation and using different solvent flow rates during extraction were observed. Four different variations were used in the extraction process trials: 63.09 cm3 s-1, 94.64 cm3 s-1, 126.20 cm3 s-1, and 189.30 cm3 s-1. Sample quantities of 400 g and 500 g were used to upscale the analysis. The results showed that maceration did not significantly increase AGI activity (P < 0.17), but it did shorten the time needed to reach equilibrium concentration. Similarly, the solvent flow rate variations did not affect AGI activity (P < 0.078), but they shortened the extraction time. A significant decrease in AGI activities was observed when switching from laboratory to pilot scale, and an even greater decrease in AGI activity was observed when the sample quantity was increased to pilot scale. It was therefore concluded that lemongrass extract can only be used to maintain optimal AGI activity at the maximum sample quantity of 300 g for the percolator designed in this research, which produced an extraction yield of 39.45±1.59%.