COLOR CHARACTERISTICS AND ENZYME ACTIVITY OF PEROXIDASE AND POL YPHENOLOXIDASE IN DIFFERENT WHEAT CULTIVARS AND THEIR PASTA: 1- EFFECT OF MILLING PROCESS ON COLOR CHARACTERISTICS AND ENZYME ACTIVITY OF PEROXIDASE AND POL YPHENOLOXIDASE IN DIFFERENT WHEAT CUL TIVARS | ||
| Journal of Food and Dairy Sciences | ||
| Article 2, Volume 29, Issue 11, November 2004, Pages 6421-6433 PDF (3.42 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jfds.2004.240575 | ||
| Authors | ||
| M. T. Ramadan; H. A. Eissa; S. Y. EI-Faham | ||
| Food Technology Dep. National Research Centre, Cairo, Egypt. | ||
| Abstract | ||
| The activity of polyphenoloxidase (PPO) and peroxidase (POD) by milling different durum and soft wheat cultivars was investigated. Also, non-enzymatic browning and color characteristics were determined in milled different durum and soft wheat wheat cultivars. Milling whole-grain into bran and semolina markedly decreased POD and PPO activities in semolina fraction and increased in bran fraction. The highest activity was found in bran fraction. The POD and PPO activities were much higher both in bran fraction and whole kernel for all eight-wheat cultivars than of in semolina fraction. The PPO activity in the bran fraction was three times higher than that semolina fraction, and POD activity was six times greater. No difference in the non-enzymatic browning recorded at 420nm was found between different wheat and different wheat fractions. Results are obvious that milling process of wheat increased the development of red colour parameter a>. The a'-values were in the range of (4.39- 6.09) in whole meal, decreased to (1.10-3.02) in semolina fraction and increased to range (6.28-7.65) in bran fraction of different wheat cultivars respectively. The Hunter colour values of semolina fraction of different wheat cultivars were lower than those of bran fraction. Other color parameters such as Hue angle and chroma also indicated that heat from milling process caused a slight color change. Results indicates that whole meal, bran and semolina become yellow-green but was still reddish because the hue angle was positive. The samples of bran fraction had a 81 value higher 6 times than those of the semolina fraction. But, 81 values of whole meal were lower than those of the bran fraction and higher than in semolina fraction. Results demonstrated that wheat cvs. without bran and/or with low in POD and PPO activities would be suitable for pasta making | ||
| Keywords | ||
| Milling; Polyphenoloxidase; peroxidase; wheat; non-enzymatic browning; and color characteristics | ||
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