Effect of heat treatment on wheat dough rheology and wheat protein solubility

Abstract

In the present study, the influence of moisture content, temperature and time during heat treatment of wheat flour was investigated. Heat treatment was carried out on laboratory scale in a water bath at 50-90 degrees C for times up to 3 h. Flour functionality was evaluated by analysing protein solubility in acetic acid as well as by the formation of bread-like doughs, which were then analysed with dynamic oscillatory and rotational rheometry. Effects during heat treatment were explained on a molecular level using a simplified physical model describing wheat dough as a continuous gluten matrix with starch as filler particles. Heat treatment causes the formation of gluten aggregates resulting in decreased protein solubility and lower network strength of dough. Rheological data also indicate the formation of starch aggregates and modified interactions between gluten and starch. The effects were more pronounced in heat-treated flours with increased moisture content due to a higher mobility of the molecules.

Effect of heat‐moisture treatment of germinated wheat on the quality of Chinese white salted noodles

“…Dough stability during prolonged mixing has commonly been considered to be a factor of gluten quality. Generally, the HMT processes cause lower network strength of dough and thus significant deterioration in the mixing properties such as DDT and dough stability due to the gluten protein denaturation, similar results had been observed by Mann et al (2013) and Bucsella et al (2016). Heat-moisture treatment had a significant effect on the mixing behaviors of germinated wheat flour, both treated in form of kernel and flour.…”

“…After germination, the weakening increased obviously, indicating a decrease in the sensitivity of the dough to overmixing (Lorenz, Roewe-Smith, Kulp, & Bates, 1983). Bucsella et al (2016) conducted their experiments at 95°C for 5 min using a retention screws by a continuous process (5-20 L/ hr water), while Mann et al (2013) performed their HMT process through a water bath at 90°C for longer time (30 min), with moisture content of 16.0%-17.0%, which was closer to conditions used in this study. Thus, damage to the gluten during germination was a probable explanation for the increased weakening.…”

“…Wheat germination treatment caused reduced water absorption (59.3%), DDT (2.22 min), dough stability (5.55 min), and increased dough weakening (0.874 N m) compared to wheat flour. On the other hand, denaturation and aggregation of proteins by HMT would lead to decreased protein solubility and thus hydration ability (Mann, Schiedt, Baumann, Conde-Petit, & Vilgis, 2013). After germination, the weakening increased obviously, indicating a decrease in the sensitivity of the dough to overmixing (Lorenz, Roewe-Smith, Kulp, & Bates, 1983).…”

Comparison of the effects of different heat treatment processes on rheological properties of cake and bread wheat flours

“…CFth and BFth had higher C2 values and had lower weakening compared to that of the untreated ones. This observation contradicts the findings of Mann, Schiedt, Baumann, Conde-Petit, and Vilgis (2013). In their study dry heat treated (50-90°C up to 3 h) cake flour showed lower gluten strength due to heat-induced gluten agglomeration that was expressed in low network strength after a longer tempering period.…”

Technological properties of durum wheat semolina treated by heating and UV irradiation for reduction of mycotoxin content

“…In addition, the observed increase in the WA value is related to the higher water uptake of starch granules, as a consequence of the cross‐linked protein network loss surrounding them. Protein aggregation and starch surface modifications after heat treatment lead to changes in starch–protein and starch–starch interactions, also affecting the rheological properties of doughs (Mann, Schiedt, Baumann, Conde‐Petit, & Vilgis, ).…”