Ozone assisted autohydrolysis of wheat bran enhances xylooligosaccharide production with low generation of inhibitor compounds: A comparative study

In the present study, ozone assisted autohydrolysis (OAAH) was evaluated for enhanced generation of xylooligosaccharide
(XOS) from wheat bran. The total XOS yield with optimum ozone dose of 3% (OAAH-3) was found
to be 8.9% (w/w biomass) at 110 ◦C in comparison to 7.96% at 170 ◦C by autohydrolysis (AH) alone. Although,
there was no significant difference in oligomeric composition (DP 2–6), significant decrease in degradation
products namely furfural (2.78-fold), HMF (3.15-fold), acrylamide (nil) and acetic acid (1.06-fold), was observed
with OAAH-3 as a pretreatment option. There was 1-fold higher xylan to XOS conversion and OAAH-hydrolysate
had higher DPPH radical scavenging activity than AH. PCA plots indicated clear enhancement in XOS production
and lower generation of inhibitors with decrease in treatment temperature. Results of the study therefore suggest
OAAH can be an effective pretreatment option that can further be integrated with downstream processing for
concentration and purification of XOS.