Processing of hazelnut (Corylus avellana L.) shell autohydrolysis liquor for production of low molecular weight xylooligosaccharides by Aureobasidium pullulans NRRL Y–2311–1 xylanase

[Display omitted] •Authoydrolysis integrated with sequential enzymatic hydrolysis was used.•The proposed strategy was effective for low-DP-XOS production from hazelnut shell.•A. pullulans xylanase exhibited superior properties for low-DP-XOS production.•Maximum low-DP-XOS production was obtained at pH 5.0 and 40 °C with 240 U/g XOS.•The low-DP-XOS concentration reached to 22.5 g/L after optimization. In this study, a versatile process for the production of xylooligosaccharides (XOS) with a low degree of polymerization (DP 2–6) from hazelnut shells was designed. This process included autohydrolysis integrated with sequential enzymatic hydrolysis by crude xylanase produced with Aureobasidium pullulans NRRL Y–2311–1 from wheat bran. Autohydrolysis of hazelnut shells was carried out at a solid:liquid ratio of 1:6 (w/w) and 190 °C non-isothermally. The effects of several parameters on enzymatic hydrolysis of the autohydrolysis liquor were determined. The maximum XOS (DP 2–6) production was 22.5 g/L which was obtained at pH 5.0 and 40 °C using enzyme concentration of 240 U/g XOS and substrate concentration of 72 g/L. Under these conditions, 31.29 % of the substrate (total XOS) was converted to low-DP-XOS; xylobiose and xylotriose are being the major oligomers. This is the first study on the application of A. pullulans xylanase in production of xylooligomers from hazelnut shells.