Reducing phytate content in wheat bran by directly removing the aleurone cell content with teeth roller mill and ultrasonic cleaner

• There is a positive correlation between phytate content and cumulative strip ratio.
• Teeth roller mill is more effective to reduce the phytate content.
• Teeth roller mill with ultrasonic cleaner could further reduce the phytate content.
• Ultrasonic cleaner could effectively wash the cell content out from broken aleurone cells.

Wheat bran is good for human health due to the abundance of dietary fiber. However, it also contains much phytate which has been well documented as an anti-nutritional factor. This study is the first to explore the effectiveness of reducing phytate content in wheat bran by directly removing the aleurone cell content utilizing different roller mills (smooth roller, coarse smooth roller and teeth roller) and different clean-up methods (brushing and ultrasonic washing). Through analysis of phytate content in wheat bran obtained from different mill systems, the best raw material was found to be obtained from the 5B system. By investigating various roller types and clean-up methods, the optimal technique was found to use a teeth roller mill combined with ultrasonic washing, which could reduce the phytate content by the greatest amount: the reduction of phytate content achieved 62.98% (from 26.80 mg/g to 9.92 mg/g) in wheat bran. The optical microscope observation indicated that ultrasonic washing could wash the aleurone cell content out from broken aleurone cells which were destroyed by the teeth roller mill.