Abstract:

The pasting and baking properties of waxy flour under different heat treatments at 100 or 120 ℃ for 60 , 90 min
and 120 min were analyzed by RVA, DSC and TA, respectively. The results showed that (1) compared with the control group
without heat treatment, the water-holding capacity and pasting properties of waxy flour were enhanced after heat treatments.
The pasting parameters (peak viscosity, breakdown viscosity and final viscosity) were higher than those of the control. But
when waxy flour was thermally treated under specific conditions (100 ℃), dough setback showed a downward trend. (2)
DSC results showed that both To and Tp increased with longer treatment time for all samples, and △H gradually decreased
along with heat treatment time. The gelatinization temperature range was narrowed after heat treatments. (3) after addition
of thermally processed waxy flour, the specific volume of waxy bread was increased. For 100 ℃/120 min heat treatment
group, the specific volume of waxy bread was increased from 4.26 mL/g to 4.87 mL/g by 14.32% when compared with the
control group. Heat treatment could be beneficial for reducing the hardness, gumminess and chewiness of waxy bread. The
lightness for bread made from heat treated waxy flour decreased with the extension of heat treatment time and increase of
heat treatment temperature. Bread with 30% substitution of waxy flour treated at 100 ℃ for 60 min showed the best sensory
quality.

Key words: heat treatment, waxy flour, pasting properties, baking performance