Effect of Microwave Treatment on the Browning and Characteristics of Fresh and Wet Noodles
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
The effects of microwave treatment of wheat flour on the browning and properties of fresh wet noodle were investigated in the present study. Wheat flour was microwaved, before the color of fresh wet dough sheet and polyphenol oxidase (PPO) activity were determined. Also, the effects of microwave treatment on the browning and its characteristics of fresh-wet noodle were studied through analyzing the changes in moisture distribution, free polyphenol content and rheological characteristics of dough sheet, as well as changes in the secondary structure of protein, sulfhydryl group and disulfide bond of wheat flour. The results showed that the whiteness of the fresh wet dough sheet increased with the increasea of microwaving time and microwave power. There was no significant difference in color at a low microwave power, but the whiteness of dough sheet decreased due to gelatinization of wheat flour at a high power of 700 W for 100 s. The PPO activity decreased by 42.78%, and the content of free phenolics decreased by 54.78% within 24 hours compared with the untreated group. The relaxation times T22 and T23 of the dough sheet increased first then decreased, and reached the maximum when a medium-intensity treatment was applied. The free thiol group showed a downward trend, whilst the content of disulfide bond increased, which were 1.29 and 4.38 μmol/g, respectively, for a 100-s treatment at 700 W. As for protein’s secondary structure, the content of α-helices decreased significantly, whilst the content of random coils increased significantly. In terms of the rheological properties of fresh wet dough sheet, both the G' and G" increased first then decreased, and Tanδ also decreased first then increased. In summary, the treatment with a microwave power of 700 W and treatment time of 80 s leads to the best outcome. This study provides a theoretical basis for the noodle industry.
