Effects of mixing time and oxidizing and reducing agents on extractability and size distribution of gluten proteins as assessed by SE-HPLC and FIFO flow FFF.

NOVEMBER 5-9, 2000 KANSAS CITY, MISSOURI

A A C C 2 0 0 0 A n n u a l M e e t i n g

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Effects of mixing time and oxidizing and reducing agents on extractability and size distribution of gluten proteins as assessed by SE-HPLC and FIFO flow FFF. S. G. STEVENSON (1), K. R. Preston (1), and K. Takatsu (2). (1) Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada; (2) Research and Development Division, Yamazaki Baking Co., Ltd., Tokyo, Japan.

The effects of mixing water-flour dough in the farinograph in the presence of six oxidants and one reducing agent on the extractability and size distribution of gluten proteins was investigated. In the absence of oxidant or reductant, extractability in 0.05 M acetic acid increased with increased mixing time while the remaining amount of protein extractable with 0.05M acetic acid with sonication showed a corresponding decrease. Size-exclusion high performance liquid chromatography (SE-HPLC) and frit-inlet/frit-outlet flow field-flow fractionation (FIFO-flow FFF) showed that mixing dramatically reduced the amount of larger polymeric protein while the proportion of acetic acid extractable smaller polymeric and monomeric protein increased. Faster acting oxidants and the reductant increased the rate of breakdown of the larger polymeric proteins during mixing while the impact of slower acting oxidants was less evident.