Total phenolic content determination
Total phenolic content of snack bar or apple DF was analysed
followed the method of Singleton, Orthofer, and Lamuela-Raventos
(1997) and expressed as catechin equivalents (CtE). The absorbance
at 760 nm was detected using a microplate reader (Spectra-
Max Plus 384, Sunnyvale, CA). A calibration curve (absorbance vs.
catechin concentration mg CtE/ml) was established for the extraction
medium.