Fundamental study on the effect of hydrostatic pressure treatment on the bread-making performance of oat flour

The effect of hydrostatic pressure (HP) has been investigated on cereal starches, proteins and flour systems, but its efficacy in cereal food processing has not been established. This study describes the use of HP as a tool to improve the bread-making performance of oat flour. For this purpose, oat batters were HP-treated at 200, 350 or 500 MPa, and the microstructure was investigated using scanning electron microscopy and bright field microscopy. Furthermore, HP-treated oat batters were added to an oat-bread recipe, replacing 10, 20 or 40% of untreated oat flour. Breads analysis revealed significantly improved bread volume upon addition of 10% oat batter treated at 200 MPa. The staling rate was reduced of all breads containing oat batter treated at 200 MPa. In contrast, bread quality deteriorated due to addition of oat batters treated at pressures a parts per thousand yen350 MPa, independent of the addition level. Overall, weakening of the protein structure, moisture redistribution and possibly changed interactions between proteins and starch were responsible for the positive effects of HP-treatment at 200 MPa on the bread-making performance of oat flour. Protein network formation and pre-gelatinisation of starch did not improve oat-bread quality.