Effect of fermentation and microwave radiation processes on physicochemical properties of wheat bran

Wheat bran is a rich source of dietary fiber and for this reason, its application in the food industry has increased. How-ever, the amount of phytic acid and its insoluble dietary fiber is high and can significantly reduce the nutritional and technological quality of food products. The aim of this study is to investigate the effect of fermentation process and microwave radiation on physicochemical properties of bran. The results showed that the amount of phytic acid de-creased from 4805.67mg/100g to 2756.67mg/100g and 3023.33 mg/100g, respectively, but while combining these two processes, there was a significant decrease in the amount of phytic acid (2205.94 mg/100g). Amount of soluble in the control sample (3.63%) decreased during the microwave process (1.06%), while increased during the fermentation pro-cess (9.30%) as well as the combined fermentation and microwave process (6.46%). The results of measurement of L*, a* and b* factors showed that the amount of L* decreased from 56.71 to 50.41, 48.74 and 46.69 during microwave, fermentation and combined process, respectively. Factor a* increased from 4.69 during the microwave process to 5.90 and to 5.46 during the combined process, but there was no significant change during the fermentation process. Factor b* increased from 26.73 to 31.92 during fermentation and 32.63 during the combined process, but decreased to 25.16 during the microwave process. The images obtained from scanning microscopy showed the creation of surfaces with smooth edges in the fermentation process and also revealed the porosity on the surface of bran particles during the microwave process. Based on the results, microwave process has a potential to reduce the amount of phytic acid and furthermore, it causes the drying of fermented bran and increases its storage time accordingly. Therefore, simultaneous use of fermentation and microwave processes is recommended for bran processing and improving its physicochemical properties.