Complex sentence: After gallic acid, hydroxytyrosol is believed to be one of the most powerful antioxidants; it's capacity is ORAC 40,000 umolTE/g, this is 10 times higher than Green tea, and 2 times higher than CoQ10.
Split into simpler sentences: After gallic acid, hydroxytyrosol is believed to be one of the most powerful antioxidants. Its oxygen radical absorbance capacity is 40,000 umolTE/g, which is ten times higher than green tea, and two times higher than CoQ10.