Strategies for xylitol purification and crystallization: A Review

Abstract

This paper reviews the literature on the main aspects of purification and crystallization of xylitol produced either by chemical or biotechnological routes. Different strategies have been used to clarify media containing xylitol: activated charcoal, pH adjustment, ion-exchange resins, membrane separation, chromatographic methods, liquid-liquid extraction and precipitation, or a combination of these techniques. This study explores the most recent results of research-work carried out in this field as well as the main approaches to recover and crystallize xylitol in a pure form. The effects of impurities, temperature, supersaturation, crystal seed amount, and size on xylitol crystal growth are also discussed. Downloaded by [Michigan State University] at 08:45 01 April 2015 A c c e p t e d M a n u s c r i p t 2

Production and purification of xylitol by Scheffersomyces amazonenses via sugarcane hemicellulosic hydrolysate

“…Another challenge in the xylitol fermentation process is its recovery from the broth. Few studies related to xylitol recovery are reported . Generally, in bioprocesses, recovery and purification are complicated steps that interfere in the final cost of the bioproduct .…”

“…Generally, in bioprocesses, recovery and purification are complicated steps that interfere in the final cost of the bioproduct . Most of the published studies describe crystallization methods for the recovery of xylitol from fermented broth (with hemicellulosic hydrolysates of hardwood, corn cobs, sugarcane bagasse, and synthetic mediums) with a yield between 40% and 60% and purity less than 98% . However, non‐conventional recovery technologies, such as supercritical fluid extraction, are being evaluated for different applications in biorefineries …”

“…Few studies related to xylitol recovery are reported. 19 Generally, in bioprocesses, recovery and purification are complicated steps that interfere in the final cost of the bioproduct. 20 Most of the published studies describe crystallization methods for the recovery of xylitol from fermented broth (with hemicellulosic hydrolysates of hardwood, corn cobs, sugarcane bagasse, and synthetic mediums) with a yield between 40% and 60% and purity less than 98%.…”

“…20 Most of the published studies describe crystallization methods for the recovery of xylitol from fermented broth (with hemicellulosic hydrolysates of hardwood, corn cobs, sugarcane bagasse, and synthetic mediums) with a yield between 40% and 60% and purity less than 98%. 19 However, non-conventional recovery technologies, such as supercritical fluid extraction, are being evaluated for different applications in biorefineries. 21,22 A variety of solvents may be used as supercritical fluids, but carbon dioxide (CO 2 ) is often the most used due to its easy-to-reach supercritical conditions.…”

Synthesis and Characterisation of Polyethersulfone Membranes Incorporated with Titanium Dioxide Nanoparticles for Xylitol Separation from Mixed Sugars Solution

“…3 Xylitol could also be commercially obtained chemically by using catalyst, 4 or biotechnologically by using fungi, bacteria or yeast. 5 The separation performance of xylitol is a complicated process due to presence of impurities and this separation can be achieved by using different techniques such as: (1) crystallisation (75%), 6 (2) adsorption (60%), 7 or (3) membrane technology (82%). 8,9 Based on this, membrane technique is reported to have given the highest purity compared to others.…”