How to calculate total phenolic content:
1) Plot the standard calibration curve:
- plot absorbance vs standard concentration (10-100 ug/mL)
- obtain the equation y=mx+c
- ensure R2 is more than 0.95
y=absorbance, x=concentration, m=slope, c=intercept
2) Calculate the concentration of phenolic content in samples using the equation y=mx+c
- rearrange equation; x=(y-c)/m
- x is the concentration of phenolic content in ug/mL
- convert ug/mL to mg/mL if necessary
3) Calculate the total phenolic content (TPC)
- TPC = cv/m
c=concentration of phenolic content
v=volume of methanolic extract solution used
m=weight of extract per mL in gram unit
