Effects of particle size in wasted bread flour properties

Bread is wasted at different stages in the food value chain, mainly in industry and retail markets. Wasted bread can be milled into flour to be used in the elaboration of other food products. Milling can generate flours with different particle sizes that influence their properties. This study analysed the effect of particle size (200, 500 and 1000 μm) on the hydration, pasting and gel properties of flours elaborated with four different stale breads. Bread flours show a higher cold water absorption capacity and a lower oil absorption capacity than wheat flour. No differences in water absorption properties after heating were observed. The viscosity curves of bread flours presented lower values than wheat flour curves, and the gels obtained were weaker. Bread flour properties were not influenced by different particle sizes. Therefore, a less aggressive milling, with a lower energy cost, can generates flours with properties similar to finer flours. Flour of different particle size (200, 500 and 1000 μm) of wasted breads were analysed. Hydration, pasting and gel properties of flours were studied. Bread flours show a higher cold water absorption capacity, lower oil absorption capacity, viscosity curves with lower values and weaker gels than wheat flour. Bread flour properties were not influenced by different particle sizes.