Whole-flours from hard and soft wheat genotypes: study of the ability of prediction test to estimate whole flour end-use.

The aims of this work were to assess the influence of the physicochemical composition of whole flour from soft and hard wheat genotypes on cookie and bread properties, as well as the ability of the prediction tests to estimate the whole meal flour end-use. Flours from hard and soft wheat genotypes proved to have different chemical composition and particle size distribution. Flours from hard wheat had lower particle average size and dietary fiber content, and higher lipid and wet gluten contents than flours from soft wheat. Particle size distribution, water absorption capacity and chemical composition of whole flours strongly influenced bread and cookie making performance. Considering prediction tests, flours from different wheat types were successfully discriminated using SDS-SI, SRC lac, and GI. However, rather weak correlations were found between the prediction test and the cookie and bread quality parameters. The prediction test, standardized for refined flours, showed a poor performance when whole flours were used. Nevertheless, grain texture and whole flour physicochemical properties did affect bread and cookie quality parameters, thus classical prediction tests should be modified in order to estimate the end-use performance of whole flours. Moreover, a standardization of the milling process should be considered.

Flour and starch characteristics of soft wheat cultivars and their effect on cookie quality.

Studies on Argentinian soft wheat cultivars are scarce, although the flours obtained from these wheats are the most suitable for cookie making. This work studies the behavior of the flours obtained from 44 adapted soft wheat lines harvested in two consecutive years for cookie making, focusing on starch properties. Starch granule size distribution, and thermal and pasting properties of flour samples were studied. Large variations in flour and starch characteristics were found between all experimental lines, indicating a wide variability among wheat genotypes and a noticeable effect of crop year conditions. Starch granule size distribution showed the typical bimodal distribution observed for wheat. Flours with higher proportion of large A-type granules were associated with lower damaged starch (DS). As expected, the lower the DS content, the lower the solvent retention capacity, gelatinization temperature and enthalpy, with a positive impact on cookie diameter. Flours from soft wheat genotypes with higher proportion of large A-type granules were associated with lower DS content and reduced water absorption capacity. Both genotype and environment exert an effect on soft wheat flour characteristics.