The difference between the red line and the blue and white line of Queen Japanese bread flour lies in the quality and price.

1. quality: the red line is grade a flour, with finer workmanship and whiter color. In contrast, the quality of the blue and white thread is slightly inferior, and it is B-grade flour with a slightly darker color.

2. Price: The red line is more expensive than the blue and white line.

I hope the above information can help you solve the problem. If you have any other questions, please consult relevant professionals.