Effect Of Ozone Treatment On Wheat Flour Quality

Because ozone treatment has an important effect on the quality of wheat flour,this paper intends to control different ozone treatment time(0,5 min,15 min,30 min)and ozone intensity(0.61 g/h and 3.82 g/h)to determine the processing quality and edible quality,so as to clarify the changing law of ozone treatment on the quality of wheat flour and steamed bread.Two different conditions(wheat flour was improved:0.70 g/h,15min;wheat flour was deteriorated:3.82 g/h,15 min)of ozonized wheat flour were selected to mix with unozonized wheat flour in different proportions,so as to clarify the changing law of wheat flour and steamed bread quality with different mixing ratio.The effects of high and low ozone treatments on the p H value,gelatinization characteristics,dough characteristics,protein structure,moisture distribution of the dough and the quality of the steamed bread were compared.The results show that:during low-intensity ozone treatment,with the extension of ozone treatment time,the peak viscosity,dough formation time and stability time of wheat flour increased significantly;low molecular weight protein polymerized into polymer;the value of T₂₁ and A₂₁decreased significantly,but the value of A₂₂ increased significantly;the specific volume,hardness,chewiness and resilience of steamed bread were smaller,and the brightness of slices increased significantly.During high-intensity ozone treatment,with the extension of ozone treatment time,the p H value,the peak viscosity and water absorption of wheat flour increased significantly;the dough formation time and stability time increased first and then decreased;the IPP content increased significantly,but the SPP content and Gli content decreased significantly;the degree of cross-linking of low-molecular-weight proteins were increased;the value of T₂₁,T₂₂and A₂₁ decreased significantly,but the value of A₂₂increased significantly;when the ozone treatment time was more than 15 min,the hardness and chewiness were greater,the specific volume,elasticity,resilience,the number of pores and brightness of slices were smaller.The changes of lipid and volatile components of wheat flour before and after treatment with different intensities ozone were analyzed and compared.The results show that:during low-intensity ozone treatment,with the extension of ozone treatment time,the fatty acid value and the composition of fatty acid of wheat flour changed little;the content of malondialdehyde increased significantly;and the types and concentrations of volatile substances changed significantly.During high-intensity ozone treatment,with the extension of ozone treatment time,the fatty acid value and malondialdehyde content of wheat flour increased significantly;the content of unsaturated fatty acids such as oleic acid linoleic acid and linolenic acid decreased;and the types and concentrations of volatile substances changed greatly.Moreover,the volatile components between wheat flour treated with ozone of high intensity for more than 15 minutes and wheat flour treated with ozone of low intensity were quite different,including 2-pentylfuran,2-pentanone,2-heptanone,1-octen-3one and 2-ethylpyrazine and so on.Two ozonized wheat flours treated with different intensities were mixed into unozonized wheat flour,and the qualities of the mixed flour and the steamed bread were compared.The results show that:compared with unozonized wheat flour,the p H value,the dough formation time and stability time,the protein content and protein molecular weight distribution,the dough moisture distribution,and the specific volume,hardness and chewiness of mixed flour could be changed by adding different amounts of ozonized wheat flour.There is little difference between the three low-intensity ozonized mixed flours.When the addition amount of high-intensity ozonized wheat flour is higher,the quality of the mixed flour is closer to that of over-ozonized wheat flour.