Polyphenol oxidase (PPO) activity during germination and early seedling growth of wheat (Triticum aestivum) and effect of seed size, abrasion and light on its activity

Abstract

The most important widespread cereal is Wheat (Triticum spp) which is used throughout the world. An important problem for the flour and flour related products is their darkening and discoloration which is believed to result from polyphenol oxidase (PPO) activities. The most important enzyme responsible for browning of end product in wheat is Polyphenol oxidase (PPO). The factors affecting PPO activity may be germination, light; seed size during germination of wheat grains, the Polyphenol oxidase activity was studied in wheat grain. Increase in PPO activity was observed in bran tissues at the start of germination and gradual decrease with time on 4^th day of germination occurred. An increase in PPO activity was observed up to 4^th day and it was decreased on the 5^th, 6^th, and 7^th day of germination in both embryo and endosperm, while increased in young seedlings.  The effect of light on Polyphenol oxidase (PPO) activity in wheat grain was monitored during germination increased in (PPO) activity was recorded. A successive decrease in seed weight and rising in abrasion time was documented. Stability of PPO is clear in dry seeds and the minor harm come across during harvest or threshing which does not make significant rise and decline in enzymatic action. High enzymatic action was noted in large seed than the smaller ones. A successive decrease in seed weight and rising in abrasion time was documented. Stability of PPO is clear in dry seeds and the minor harm come across during harvest or threshing which does not make significant rise and decline in enzymatic action. Main emphasis of this study was on evaluating PPO activities during germination and factors affecting its activity.