Wheat flour of different qualities: influence of protein content and different emulsifiers on rheological parameters

PONZIO N.; FERRERO C.; PUPPO M.C.

Santiago de Chile

Congreso; II Conferencia Latinoamericana de Cereales; 2011

GRANOTEC

Varietal wheat flours of different quality present differential behaviour when additives are added. Wheat production offers a wide variation on protein percentage which determines different industrial usage. Therefore, the aim of this work was to study the effect of different protein content (low and high N content) in two varietal flours of quite different baking quality, additioned with two emulsifiers, one synthetic, tartaric acid of monoesthers (DATEM)  and a natural one (soybean lecithin, LS); each one of them in three levels (0, 1 and 1,5%). Wheat flour with a different pattern of high molecular weight glutenins, baking quality and protein content (low content = n; high content = N), Baquette 10 (B10) and Buck Pronto (BP) were characterized by physicochemical (% wet gluten, % WG, % ash, sediment high), enzymatic (falling number, FN) and rheological assays through alveographic (P, L, P/L, W) and farinographic (WA, DT, STAB, Soft) parameters. Varietal flours showed significant differences in several parameters. B10 showed the lowers values for physicochemical parameters in n condition. A higher alveographic force was found in BP in both protein levels, n and N. B10 instead, in N improved significantly W values, therefore P/L relationship showed more equilibrated values (P/L @ 1). On the other hand, BP showed the highest development time, stability and the lower softening, in both levels of protein. Tenacity and Extensibility were increased with DATEM in B10, n and N, both of them; P/L remarkable decrease was firstly associated to protein level than the presence of the emulsifier. Inverse effect was showed in P and L with LS in increased levels, at n condition. Higher concentration of DATEM increase P values and decrease L values in BP in n condition, affecting P/L relationship. LS effect on P in BP flour was insignificant in n and N.  Extensibility was affected by LS only in n condition. Genotype, protein level and emulsifiers doses showed a different pattern in farinographic behaviour. Neither DATEM nor LS improved DT or Stability in B10 n, while in N, higher levels of emulsifier decreased both parameters. Instead, BP n with LS, presents an important decrease of stability. BP N in presence of LS showed greater changes than DATEM added. We can conclude that rheological performance is regulated mainly by wheat genotype and by protein content due to nitrogen fertilization and, in a less proportion by the nature and level of the emulsifier.