Enhancement of fructan extraction from garlic and fructooligosaccharide purification using an activated charcoal column

Abstract Conventional fructan extraction from most plant sources involves water combined with methanol or ethanol in different solvent ratios, time, and temperature combinations to increase extraction efficiency. Fructan recovery step is usually very laborious using such conventional methods. Three different extraction methods from literature giving optimum fructan yield were compared. Methanol (62.5%) at 55 °C, 15 min was effective and efficient to extract fructan from garlic (18.71 g/100g) compared to the other two methods. Further, in this study, extraction of fructan from garlic was optimized in a rapid solvent extractor system at room temperature (25 °C) with methanol (70%), which increased the fructan yield by 32.20% (20.73 g/100g), with minimal loss in garlic powder recovery. Hemicellulase treatment followed by solvent extraction increased the yield to 21.23 g/100g (total increase of 35.4%) compared to the conventional hot water method. Purification of fructooligosaccharides (FOS) from a mixture containing 15.68 g/100g of fructan in garlic extract using activated charcoal gave 94% 1-kestose in shake flask and 82.4% in a column.