What is the function of egg in short crust pastry?

In shortcrust pastry, the egg primarily serves as a binding agent, helping to combine the ingredients and enhance the dough's structure. It adds richness and moisture, contributing to a tender texture. Additionally, the egg can provide a slight sheen when brushed on the pastry before baking, improving its appearance. Overall, it plays a crucial role in achieving the desired consistency and flavor of the pastry.