2.4. Determination of α-Amylase inhibitory activity

The α-amylase inhibition assay was adapted from Apostolidis et al. (2006) with slight modifications. 40 μl yogurt aqueous extracts and 10 μl α-amylase solution (0.5 mg/ml) were incubated at 25 °C for 10 min. This was followed by the addition of 100 μl amylase substrate mix (amylase activity assay kit, Sigma-Aldrich, Dorset, UK). The reaction mixtures were incubated at 25 °C for 10 min and the absorbance were read at 405 nm using a SpectraMax 190 microplate reader (Molecular Devices Limited, Berkshire, UK). The readings were compared to a control which contained 40 μl of buffer solution instead of the extract. The enzyme inhibition was calculated as below: