Improved separation of polymeric and monomeric protein fractions using a high resolution column
The main objective of this study was to test the Yarra-SEC 4000 analytical column (300 x 7.80 mm) against the BioSep-SEC s4000 narrow bore column (300 x 4.60 mm) that was used by most researchers up to now, for separation of wheat gluten proteins, using SE-HPLC. The relationship between protein fractions and a range of quality characteristics were then determined. The trials were conducted in the three production areas of South Africa representing the dryland summer rainfall, dryland winter rainfall and irrigated regions. These regions each have specific cultivars developed for their specific conditions. The Yarra-SEC 4000 analytical column yielded nine profile peaks compared to the five of the BioSep-SEC s4000 narrow bore column. Highly significant differences were found between the protein fractions for the irrigated region and the winter rainfall cultivars. Very few significant differences were seen for protein fractions between cultivars in the dryland summer rainfall region. The GLI%p correlated positively with dough rheological characteristics in cultivars of the irrigated region. The UPP positively correlated with dough rheological parameters for cultivars of the irrigated region. No significant correlations were observed between UPP and dough rheological characteristics in the dryland winter rainfall cultivars. The irrigated region cultivars presented more significant correlations between protein fractions and quality characteristics. Significant correlations were obtained between SDSVOL and protein fractions for the winter rainfall region cultivars. No significant correlations were obtained between SDSVOL and protein fractions for the irrigated and dryland summer rainfall cultivars. In this study it was observed that Yarra-SEC 4000 analytical column can be employed successfully in the separation of wheat proteins.