The effect of pentosanase on the solubilisation and degradation of arabinoxylan extracted from whole and refined wheat flour.
BACKGROUND
The quality improvement capability of pentosanase (Pn) for whole-wheat Chinese steamed bread (CSB) is not as efficient as that for refined CSB. However, the underlying mechanism remains to be elucidated. In this work, water-extractable arabinoxylan (WEAX) and water-unextractable solids (WUS) were extracted from whole and refined wheat flour, and then treated with Pn under the conditions similar to CSB-making. Solubilisation and degradation of arabinoxylan (AX) caused by Pn treatment were determined.


RESULTS
WEAX from whole flour exhibited higher molecular weight than that from refined flour before and after the treatment with equivalent Pn. Compared with WUS from refined flour, WUS from whole flour had a much lower dissolution degree but the degradation of AX released from the WUS was more efficiently. Moreover, AX released from WUS for refined flour showed a higher Ara/Xyl ratio and the percentage of residual ferulic acid in WUS decreased more significantly.


CONCLUSIONS
The difference in quality improvement degree for Pn in whole-wheat and refined CSB might be mainly explained by its effect on WUS. That is, Pn contributed much more to the solubilisation of WUS from refined flour but provoked degradation predominantly on AX solubilised from WUS isolated from whole flour. © 2016 Society of Chemical Industry.
School of Food Science and Technology in Jiangnan University, Wuxi, Jiangsu, 214122, China.
Wei
W
Yang
School of Food Science and Technology in Jiangnan University, Wuxi, Jiangsu, 214122, China.
Zhijian
Z
Jiang
Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Liya
L
Liu
Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Yanjun
Y
Lin
School of Food Science and Technology in Jiangnan University, Wuxi, Jiangsu, 214122, China.
Li
L
Wang
Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Sumei
S
Zhou
D001939:Bread / Q000032:analysis*; D055598:Chemical Phenomena; D002681:China; D003296:Cooking; D003373:Coumaric Acids / Q000032:analysis; D032641:Eurotiales / Q000201:enzymology; D005433:Flour / Q000032:analysis*; D005511:Food Handling; D063427:Food Quality; D005656:Fungal Proteins / Q000378:metabolism; D006868:Hydrolysis; D055595:Mechanical Phenomena; D008970:Molecular Weight; D010429:Pentoses / Q000378:metabolism; D012995:Solubility; D013227:Steam; D013379:Substrate Specificity; D014908:Triticum / Q000737:chemistry*; D014783:Viscosity; D000067348:Whole Grains / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014995:Xylosidases / Q000378:metabolism*
D003373:Coumaric Acids; D005656:Fungal Proteins; D010429:Pentoses; D013227:Steam; D014990:Xylans; C085118:arabinoxylan; C004999:ferulic acid; D014995:Xylosidases; C110296:arabinoxylanase
Chinese steamed bread; WEAX; WUS; pentosanase; refined wheat flour; whole-wheat flour