A novel extremophilic xylanase produced on wheat bran from Aureobasidium pullulans NRRL Y-2311-1: Effects on dough rheology and bread quality

An extremophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 was produced on wheat bran and its performance in bread making was investigated for the first time. Two different world-wide-used commercial xylanase preparations were also applied in bread making as comparison. Effects of different enzyme dosages on various farinograph and extensograph properties of the dough and bread quality were evaluated in detail. The novel xylanase provided increase in water absorption, development time and stability of the dough and decrease in dough softening degree and mixing tolerance index at a dosage of 100 U/100 g flour. None of the enzymes provided reasonable increase in dough extensibility. There was no direct correlation between the extensograph properties (mainly, resistance and extension) of the bread dough and the bread specific volume. A. pullulans xylanase (125 U/100 g flour) provided remarkable improvement (30%) in bread specific volume as compared to the commercial counterparts. The moisture content values of all the bread samples were within the ideal limits (35-40%). A. pullulans xylanase was the most effective enzyme in decreasing the crumb firmness. Slight improvements in cohesiveness and remarkable decline in springiness and gumminess were observed for all the enzymes tested. The results of this study provide an opportunity for A. pullulans xylanase to be used in bread making at industrial scale. (C) 2018 Elsevier Ltd. All rights reserved.