αamylase is an enzyme that splits bonds anywhere along the polymer chain of starch. This results in lowering of viscosity and is mostly seen during storage and not directly after production.

αamylase:
• Found in various ingredients such as spices, fruits, meats, nuts, eggs
• Causes a decrease in viscosity
• Could be deactivated with heat

The video is showing a starch cook with added, not heattreated nuts. It shows an optimal viscosity directly after production. When storing the product, a drastic viscosity drop could be observed after some time resulting from the enzyme activity (of the not heattreated nuts).