Histochemical Localization of Polyphenol Oxidase and Peroxidase from Metroxylon sagu
Onsa G. H.1, Nazamid B. S.2*, Jinap S.2, Bakar J.2, Abdulkarim S. M.2 and Shamsul B.3
1Food Processing Research Center, Shambat, Khartoum, Sudan
2Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
3Biotechnology and Strategic Research Unit, Malaysia Rubber Board, 47000 Sg. Buloh, Selangor Malaysia.
*Author for Correspondence.
Dept. of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
Tel:+603 89468371; Fax:+603-89423552; Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract.
Polyphenol oxidase (PPO) and peroxidase (POD) activities were visualized histochemically at the cellular level of a young and a mature tree of Metroxylon sagu employing histochemical technique. In the mature tree, intense PPO activity was observed in the cell wall of the parenchyma and xylem cells when visualized under light microscope. Pith collected from the young tree showed PPO activity in the amyloplast and mitochondria inner membrane and to some extent in the golgi complex and endoplasmic reticulum. Whereas, a positive POD reaction product was visualized in the cell wall, peroxisomes and to some extent in the cytoplasm and the vacuole. The localization of PPO activity in the amyloplast and being adsorbed by the starch granules is in line with the general view that enzyme is involved in the browning of sago starch.
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