Physic-chemical and functional characterisation of argentinean wheat related to the industrial quality

A COLOMBO; GT PEREZ; PD RIBOTTA; AE LEON

Rosario, Argentina

Congreso; 1a ICC Latinoamerican Conference on Cereals and Cereal Products; 2007

ICC

It is very important to assess wheat flour quality in order to know its attributes for baking product elaboration. In breeding programmes, in which only small amounts of flour are available, this information is required immediately. As a result, several predictive tests closely related to flour quality are usually used. There is no study that determines which of these tests is more accurate for quality prediction of Argentinean wheat. Likewise, the fundaments of the tests are not well established. The aim of this work, therefore, was to compare the predictive capacity of commonly used physic-chemical tests as well as to assess their relationship with flour components. For this purpose, flour samples were prepared from eighteen Argentine wheat cultivars. The chemical composition of the flours including protein content, total and water-soluble pentosan contents, damaged starch content, gluten content and gliadin and glutenin contents were determined. Additionally, five predictive tests were evaluated: Solvent retention capacity profile (SRC), Alkaline water retention capacity (AWRC), Sodium dodecyl sulfate sedimentation index (SDS-SI), Pelshenke test and Sedimentation index (Zeleny test). In order to determine flour quality, bread samples were elaborated from a comercially weak flour replaced at 30% with each flour under study.Besides, cookies were elaborated with 100% flour samples. Damaged starch content showed lineal associations with carbonate SRC and water-soluble pentosan content was correlated with sucrose SRC and r= 0.61 and r= 0.60 respectively, p< 0.01). SDS-IS test was influenced by protein, gluten, gliadin and glutenin contents (r= 0.82; r= 0.69; r= 0.68 and r= 0.60 respectively, p< 0.01). Zeleny test was positively correlated with gluten and glutenin content (r= 0.67 and r= 0.72 respectively, p< 0.01). To assess the predictive capacity of the proposed tests, cookie factor (CF) was calculated cookie height and width. This parameter was negatively correlated with carbonate, sucrose and water SRC (r= -0.72; r= -0.64; and r= -0.81 respectively, p< 0.01). Lower correlation was found between CF and AWRC (r= -0.62, p< 0.01). Bread loaf specific volume (SV) was used to evaluate breadmaking quality of flour. SV showed strong correlations with Zeleny test and lactic acid SRC (r= 0.73 and r= 0.72 respectively, p< 0.01). So, these tests were both found to be suitable in assessing breadmaking properties of flours. In conclusion, the intrinsic components of wheat flour affecting the different predictions tests were identified. High correlations were found between CF and carbonate, sucrose and water SRC parameters. Likewise, Lactic acid SRC was strongly correlated with SV. Thus, it was clearly showed the capacity of this test to produce a predictive profile closely related to cookie and breadmaking quality of Argentinean wheat flours.