2.8.2. Total polyphenol content
Total polyphenol content of juice samples were determined using Folin–Ciocalteu assay (Singleton et al., 1965) modified to a microscale (Bae and Suh, 2007). A standard curve of gallic acid (y = 0.00566x, r2= 0.9955) was prepared and results were reported as milligrams of gallic acid equivalent (GAE) per100 ml juice extract.