Fig 6. These results same fig 5. and indicated that the color of WWF was darker, redder and yellower with finer millfeed particle sizes. it was observed that WWF with finer millfeed particles exhibited significantly higher PPO activity than that with coarser millfeed particles (P < 0.05). Polyphenol oxidase (PPO) has been implicated as a leading cause of discoloration in fresh noodles and other wheat products.