Swelling index of glutenin test. II. Application in prediction of dough properties and end-use quality

Small-scale tests, including SDS and Zeleny sedimentation, gel protein, insoluble glutenin content, and a newly developed method, the swelling index of glutenin (SIG), were compared with dough and gluten rheological parameters and end-use quality parameters for 20 wheat cultivars or breeders lines. The SIG test is equal to or slightly better than the other small-scale tests in prediction of dough strength. Quality parameters were divided into two groups according to associations with insoluble glutenin content and glutenin quality. The glutenin quality is defined as the glutenin swelling properties with short swelling time (less than or equal to55 min) that are contributed by soluble and insoluble glutenin content and their swelling properties. Parameters in the first group were mainly dependent on insoluble glutenin content and appeared to reflect gluten strength. Parameters in the second group were dependent not only on glutenin content, but also on glutenin quality. Small-scale tests are best to predict quality parameters within the same group, but not those in the other group. The glutenin swelling curve, obtained with different swelling times, was correlated with mixograph or farinograph data. Dough development time in farinograph and mixing time in mixograph were strongly related to the swelling time of peak SIG value in the swelling curve (r = 0.92, r = 0.86, respectively, P < 0.001). Farinograph stability was significantly related to the time of swollen stage in swelling curves (r = 0.62, P < 0.01). Similar to mixograph or farinograph data, the glutenin swelling curves can be used to differentiate some strong cultivars that can not be differentiated by sedimentation, gel protein, and insoluble glutenin values.