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RESEARCH PRODUCT

A contribution to the study of staling of white bread: effect of water and hydrocolloid

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Abstract Staling of white bread at ambient temperature was studied using differential scanning calorimetry and dynamic mechanical thermal analysis. During storage, sample hydration varied slightly, from 0 to 0.4% per day, depending on packaging conditions. An increase in rigidity was observed, which was attributed both to starch retrogradation and to changes in the organization of the amorphous part of crumb. The glass transition temperature of crumb was not significantly modified by these structural changes. Hydrocolloids did not affect the overall shape of the viscoelastic behavior of crumb in the temperature range from −40°C to 80°C, and had a limited influence on the kinetics of starch retrogradation during storage. They decreased significantly the rate of increase in rigidity, compared to control bread. Hydrocolloids were expected to play an important role on the plasticity of the amorphous regions of crumb, either through water retention (as locust bean gum), or by inhibiting gluten-starch interactions (xanthan and alginate). Complexes between the native lipids offlour and amy lose were formed during the first two days of storage. They appeared to reduce the maximum level of starch retrogradation.