Studies On The Effect Of Milling Process On Colors Of The Wet Noodle

This study mainly focused on the discolor of flour and the poor color stability of fresh noodles which were universally concerned in the mill and the fresh noodle's processing industry at present. Through the analysing of flours'physiochemical indexes online and the fresh noodle color, the primary physiochemical indexes that affect fresh noodle color were collected. The following were the results: Flour color whiteness, ash content, the activity of flour polyphenol oxidase dynamic (PPO), and the protein content. They all significant or extremely significant positive correlation with fresh noodle color.The traditional milling technology which was largely adopted in our wheat processing industry was chosen as the research object, according to the analyses of the reason for fresh noodle browning to happen in the milling processing, combined with domestic advanced milling concepts, i.e. fine material special treatment, modifying processing and analying sampled on line, and investigating fresh noodle color stability at last. Through comparing and analyzing the two milling technology, found out the relationships of milling technology and color changes for fresh noodle.In the process of Break, the traditional milling technology emphasised separately grinding for the different size materials, and the classiffication was less between materials. However, the improved procissing payed attention to materials classification, special material treated separately and light roller , reducing the degree of brans fragmentation to ensure the integrity of brans, and extending the difference between materials in break system. Results showed that in the improved processing, the ash contents all reduced by 0.1% in 1B, 2B and 4B mill stream flow, and totally about 25 unites of PPO activity.In the Midds Reduction system, comparing with traditional processing, improving processing payed more attention on the materials classification, and was better in the ash content, PPO activity and color stability for former flour flow's. In Sizing and Residue system, because of the emphasis on the role of Purifiers, ash content and PPO activity were lower than the traditional milling technology.The Purifiers and Re-dust system of flour flow comparison of two processes can be drawn: improving milling process combinated with the special treatment for special materials, extending the flow length of clearing flour, reducing the cross-contamination of different materials and respectively purifying for materials of different PPO activity, to enhance the purity of materials into the mill, lowering the ash content, PPO activity and the wet patches color values on the flour millstream .From the laboratory milling of wheat debranning process, it can be concluded: With the increasing of debranning number, the flour ash content, PPO activity was significantly increased, and fresh patches color values increased significantly, which verified that after the treatment of wheat debranning, simple laboratory milling processes were not in favor of maintaining the stability of the fresh noodle color.