Use of a New GH8 Family Xylanase in Baking and Milling

Transcription

1 Use of a New GH8 Family Xylanase in Baking and Milling Dr. Irina Matveeva Novozymes A/C The 24th Annual IAOM MEA District Conference & Expo's Technical Session Sousse, Tunisia, 5-8 November

2 2 Agenda Arabinoxylan in wheat flour Xylanase functionality in baking Substrate specificity NMR and HPLC results Naturally uninhibited Benefits in milling and baking industries

3 3 Arabinoxylan in wheat flour Main wheat kernel components Starch 65-70% Proteins 10-12% Non-starch polysaccharides (NSP) 2-3% Lipids 1.5-2% Arabinoxylan in wheat flour AX make up 85% of NSP 25-30% is water extractable (WE) 70-75% is water un-extractable (WU)

4 4 Extent of AX degradation Functionality in baking WU-AX HMW WE-AX Gas cell perforation Coalescence and decreased gas retention Lower stability of dough foam Lower loaf volumes with coarser crumb Increase in viscosity Redistribution of previously bound water Better dough foam stability and gas retention Crumb structure homogeneity and increase in loaf volume Gas cell Dough matrix WU-EX LMW WE-AX Drop in dough viscosity Too excessive water release Risk of too soft and sticky dough Poor machinability Reference: Courtin & Delcour Arabinoxylans and endoxylanases in wheat flour bread making. Journal of Cereal Science 35,

5 5 Xylanases are vital for bread making General mode of action for xylanases Water-unextractable arabinoxylan (WU-AX) Principles of desired xylanase impact on dough properties Solubilization of waterunextractable arabinoxylan Endoxylanase Water-extractable arabinoxylan (WE-AX) Redistribution of water in dough Improved gluten network formation Dry, balanced dough Softness Stickiness Extensibility Elasticity Xylose Arabinose Ferulic acid

6 6 Xylanase families used for baking GH8 GH10 GH11

7 7 Substrate specificity? How does the GH8 family differ in degradation of arabinoxylan compared to GH11? The specificity of GH8 has been investigated by 1 H NMR spectroscopy and HPLC and compared to GH11

8 8 Degradation of arabinoxylan GH11 GH8 GH11

9 DP4 DP5 DP3 DP2 9 HLPC measurements HPLC: LW- and HW AX and Insoluble AX h 2 GH8, 1 GH11 Bigger DP s icoshift chromatograms -An ultra rapid and versatile tool for the alignment of spectral datasets Savoranni, et al. 2010

10 Scores PC#2 (20.1%) 10 Multivariate approach on HPCL data PCA Scores [LatentiX] GH8 var I GH8 var II GH GH8 var I GH8 var II GH11 PCA Loadings PC #1 PC # Scores PC#1 (56.6%)

11 11 Substrate specificity GH8 is very active and is only cleaving between unsubstituted xylose resulting in large amount of AX oligomers and a small amount of free xylose GH11 is slower and is cleaving next to un-substituted and mono-substituted xylose resulting in large amount of free xylose. The kinetics and the end-products of GH8 differ from GH11 GH11 GH8

12 12 New xylanase technological tolerance Protein engineered in one of the loops lining the active site to modify substrate specificity and thereby reduce dough stickiness Model of active site of new xylanase Naturally uninhibited Robust performance regardless of flour types High quality bread across different production parameters High performance in various bread types

13 13 Performance in different recipes White pan bread French baguette GH8 GH11 GH11 Bac. sub Bac. sub A. niger GH8 GH11 GH11 GH11 Bac. sub A. niger Bac. sub Bac. sub Chorleywood bread GH8 GH11 GH11 GH11 Bac. sub A. niger Bac. sub Bac. sub

14 14 Conclusions New xylanase Panzea is related to GH8 family cleaving between un-substituted xylose resulting in large amount of arabinoxylan oligomers and a small amount of free xylose: - makes dough more tolerant to different flour quality and variations in processing parameters - combines superior volume performance and desired texture and appearance with a dry, balanced dough all in one product

15 THANK YOU ANY QUETIONS? Acknowledgment for generous contribution of R&D and TS Baking Departments of Novozymes