Dados do Trabalho

Título

RAPID VISCO ANALYSIS (RVA)OF WHEAT FLOUR (FTB) WITH ADDED TRANSGLUTAMINASE ENZYME (TGase)

Introdução

The average starch content in wheat flours generally ranges between 70% and 75% of the dry weight. This value vary slightly depending on the origin of the wheat and milling process used. Among the most important functional properties of starches are their thermal and pasting properties. The pasting behavior is usually studied by observing changes in the viscosity of a starch system based on rheological principles. In bread dough formation, starch performs the functions of i) water absorption and gel formation; ii) dough structure and volume; iii) gas retention; iv) moisture preservation; and v) participation in chemical reactions, mainly in color and crust formation. When used in bakery products, the reactions promoted by the enzyme transglutaminase result in the modification of the functional characteristics of these products, as various proteins bond, forming a protein network with a viscoelastic texture more suitable for baking. The purpose of the present study was to evaluate whether the addition of the enzyme transglutaminase (85 ppm and 140 ppm) modifies the pasting properties as measured by RVA.

Material e Métodos

The pasting properties of the homogenized mixture samples of wheat flour with TGase were measured using a Rapid Visco Analyser - RVA 4500.

Resultados e Discussão

The peak viscosity in the wheat flour (FTB) sample without TGase was 1241 cP, while with 85 ppm it was 1761 cP, and with 140 ppm of TGase it was 2553 cP. The samples with enzyme addition showed higher tendency to retrogradation, calculated by difference between peak viscosity and minimum viscosity, which values were: FTB equal to 839 cP; FTB_85ppm of TGase equal to 1087 cP, while for the FTB_140ppm sample it was 1471 cP. These indicate that there is a consistent pattern regarding the impact of the addition of TGase on viscosity properties.

Conclusão

This pattern suggests that the addition of TGase increases the Peak Viscosity, Final Viscosity, and Breakdown Viscosity, while it may also increase the Tendency to Retrogradation, the magnitude of these effects being directly proportional to the concentration of TG used. The increase in rheological properties can be attributed to greater starch swelling and the formation of intermolecular bonds between proteins.