Crystalline xylitol production from corncob biomass with oral toxicity analysis

• Published in: Industrial crops and products 2022-11, Vol.187, p.115407, Article 115407
• Main Authors: Ahuja, Vishal, Dasgupta, Diptarka, Kshirsagar, Siddheshwar, Ghosh, Prasenjit, More, Snehal, Gupta, Piyush, Behera, Babita, Bhaskar, Thallada
• Format: Article
• Language: English
• Subjects: Biomass; Fermentation; Oral toxicity analysis; Wastewater treatment; Xylitol
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2022.115407

Xylitol, a five-carbon sugar alcohol, has a steady global market and finds application as a natural sugar substitute in various food and confectionery products. Biocatalytic xylitol production, although touted as a greener alternative to conventional chemical catalysis, suffers from certain challenges, the primary being high cost of production. This study demonstrates a process for food-grade xylitol production from corncob biomass with energy reduction through two major process modifications. A non-conventional fermentation strategy was adopted whereby adjusting aeration without agitation, xylitol with high yield (0.86 ± 0.015 g/g), and productivity (0.74 gL-1h-1) could be produced by a GRAS Pichia caribbica MTCC 5703 strain. Xylitol was recovered from the broth in the form of crystals using a combination of membrane-based filtration and crystallization. The crystals demonstrated ~98 % purity when quantified with 1H NMR. Oral toxicity analysis of the crystals demonstrated no adverse effect in female Winstar rats (at a loading of 2000 mg/kg body weight of animals). Overall process statistics showed that 0.584 kg of food-grade xylitol crystals could be produced from 3.5 kg of corncob biomass. The two-process modifications during fermentation and xylitol recovery enabled an energy saving of ~20.842 kW/kg of crystals, providing tremendous advantages for biorefinery-based large-scale xylitol production from corncob biomass. [Display omitted] •Food grade xylitol crystals were obtained from corncob biomass through fermentation.•Xylitol production with high yield (0.86 ± 0.015 g/g) and productivity (0.74 gL-1h-1) was attained.•Two major process modifications during fermentation and xylitol recovery enabled energy savings of ~20.842 kW/kg of crystals.•Xylitol crystals displayed no toxic effect on Female Wistar rats during oral toxicity analysis.