Direct molecular weight determination in the evaluation of dissolution methods for unreduced glutenin

• A comparison of two dissolution methods, gentle stirring and sonication, for solubilising the ultra-large wheat protein glutenin was made based on a direct determination of the molecular weight of dissolved glutenin. The possible physical breakdown of glutenin by sonication was evaluated. Glutenin was isolated by extraction with hydrochloric acid and freeze dried. The extracted glutenin was dissolved either by gentle stirring at 4 °C in phosphate buffer pH 6.8 containing sodium dodecyl sulphate (SDS) or by ultrasonication in the same SDS containing buffer immersed in an ice-bath. The weight average molecular weight and the molecular weight distribution of the dissolved material were determined using asymmetrical flow field-flow factionation using a multiangle light scattering detector coupled on-line with a refractive index detector. These determinations showed that sonication caused physical breakdown of the ultra-large glutenin proteins. The average molecular weight was found to be 5×106 after sonication and 2×107 after gentle stirring.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Annan teknik -- Livsmedelsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Other Engineering and Technologies -- Food Engineering (hsv//eng)

NATURVETENSKAP  -- Kemi -- Analytisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Analytical Chemistry (hsv//eng)

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