Why is the texture of the pasta in a store-bought pasta salad different to the texture of pasta I've cooked at home?

So I've bought a store-made pasta salad and I've tried to recreate it at home.

It consists of Penne and a tomato dressing, fairly simple, however no matter how hard I try I can't emulate the exact texture of the pasta of the store-bought salad.

At first I thought it was because I overcooked the pasta, but I was pretty certain I didn't. But to be sure I tried several different cooking times on several different batches.

To no avail, the texture I am after still eludes me. The texture of the store bought is soft, yet slightly firm and has a pleasant chewiness to it.

I checked the ingredients on the back of the pasta salad and it says the pasta is made out of Durum Wheat Semolina (and water), this is the same ingredient as the pasta I used is made from.

So now I am left wondering what the difference in texture could be down to; any ideas?