The HPLC results indicated that the extract contained 68.82 mg/g total phenols and 55.57 mg/g flavonoids, while the colorimetric method indicated 183.13 mg/g total phenols and 7.37 mg/g flavonoids.Colorimetric assay apparently overestimated the amount of polyphenols present in HELZJ. According to Bragagnolo (2001),colorimetric methods have a tendency to overestimate the levels of compounds due to the presence of interfering substances that also react with the reagents. However, chromatographic methods,although more expensive, are considered more specific, since they
are able to isolate these interferences.