Rheological properties of gluten derived from wheat cultivars with identical HMW glutenin subunit composition

Ten spring wheat cultivars possessing identical HMW glutenin subunits (2*, 7 + 8, 5 + 10) were evaluated for gluten and protein content. Gluten conten t was related to flour protein content (r = 0.98). Addition of freeze-dried gluten to the base flour (cv Alpha) to a constant protein level of 12% gen erally increased dough strength. However, the magnitude of variation in mix ing patterns depended more on the type of the supplemental gluten. Fortific ation of the base flour with the freeze-dried gluten from the cv Glenlea pr oduced mixographs with the longest mixing development time (MDT), and highe st band width energy (BWE) and energy to peak (ETP), suggesting that the so urce of gluten had a strong effect on dough rheology. The viscoelastic prop erties of undiluted wet gluten varied between cultivars during mixing refle cting differences in gluten quality. Freshly prepared wet gluten of Glenlea showed extended mixing tolerance as compared to Norseman or Alpha gluten. The wet gluten from cv Glenlea was less extensible with high maximum resist ance to extension and had a larger area under the extensigraph curve than g luten obtained from cv Norseman. Gluten prepared from the cultivars Glenlea , Bluesky and Wildcat were less soluble in aqueous propanol and produced mo re froth when the dough was washed with deionised water. The froth proteins , separated by SDS-PAGE, predominantly contained strongly stained bands in the region corresponding to molecular weight < 50 kDa. The rapid tests such as froth formation and alcohol solubility used in this study to discrimina te various glutens were highly correlated with the mixograph parameters. Th ese methods can be of practical value in evaluating gluten quality. (C) 199 8 Society of Chemical Industry.